- Type of paper
: Paper in book
Title: INFLUENCE OF ENVIRONMENTAL CONDITIONS ON ADHESIVE JOINT
FAILURE
- Authors:
- Kovačević, Vera (74041)
- Mudri, Irinej (164763)
- Šmit, Ivan
- Hace, Drago (15006)
- Bravar, Mladen (5281)
- Ažman, J.
- Editors
- Allen, K.W.
Publisher: Elsevier Applied Science
ISBN: 1-85166-584-6
Year: 1991
Pages: from 162 to 195
Number of references: 32
Language: engleski
Summary: Effect of components in polychloroprene adhesives on
adhesivejoint failure, such as terpenephenolic resin, mineral additivesand
crossling agent were investigated. The properties of adhesivecomposition
and components in the form of films were alsodetermined before and after
degradation, by using spectroscopic,PSC, TG and X ray analysis. The
mechanical behaviour of adhesivefilms and adhesive joints in various
environmental conditionswere explained by mechanisms of structural and
morphologicalchanges in adhesive layer. Relative lower content of
crystallinephase after degradation depend on additives and could
influenceon adhesive system stability
Keywords: polychloroprene adhesives, components, terpenephenolic resin. adhesive film degradation, adhesive joint failure.
- Type of paper
: Paper in journal
Title: CATALYTIC PREPARATION OF DIACETONE ALKOHOL IN CONTROLLED
FLOW CONDITIONS
- Authors:
- Sišul, Nikica (43395)
- Ciković, Nada (6892)
- Jelenčić, Jasenka (41450)
Journal: React. Kinet.Catal.Lett.
Number: 1
ISSN: 0033-1736
Volume: 45
Year: 1991
Pages: from 111 to 117
Number of references: 13
Language: engleski
Summary: Catalytic preparation of diacetone alcohol from acetone
wasstudied using strong basic ion exchangers as catalysts. Acontinuous
process was carried out in an enlarged laboratoryset-up with controlled
flow rate. Experiments were performed withrespect to experiment duration,
temperature, flow rate, catalystporosity and catalyst-acetone ratio. The
quantity of DAA wasdetermined by gas chromatography. The effects of
temperature,catalyst porosity and catalyst-acetone ratio on the
reactioncourse were significant in comparison with other
parametersexamined. An exponential dependence of C/A ratio on DAA yield
wasfound.
Keywords: acetone, aldol condenzation, catalyst, diacetone alcohol, flow rate, gas chromatography, ion exchanger, kinetics
- Type of paper
: Paper in journal
Title: CATALYC PREPARATION OF MESITYL OXIDE FROM ACETONE
- Authors:
- Sišul, Nikica (43395)
- Ciković, Nada (6892)
- Wolf, Nikola (54274)
- Jelenčić, Jasenka (41450)
Journal: React. Kinet.Catal.Lett.
Number: 1
ISSN: 0033-1736
Volume: 47
Year: 1992
Pages: from 65 to 71
Number of references: 8
Language: engleski
Summary: In the process of the aldol condensation of acetone
thepreparation of mesityl oxide has been studied with respect to
thetemperature and the nature of catalyst. Strong basic ionexchangers
Ionenaustauscher III (Merck III) and Lewatit MP 500were used in the
temperature range from 0 to 50 C. Better resultsare achieved with Merck
III, as is evident from DAA/MO yields,rate constants and energy activation
values. Empiricalexpressions for DAA/MO production are given.
Keywords: acetone, activation energy, aldol condensation, diacetone exchangers, mesityl oxide.
- Type of paper
: Paper in journal
Title: METHODS FOR THE DETERMINATION OF THE CROSSLING DENSITY AND
THE FLORY-HUGGINS PARAMETER X APPLIED TO EPDM VULCANIZATES
- Authors:
- Hrnjak-Murgić, Zlata (120683)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Journal: Kautsch.Gummi.Kunsts.
Number: 11
ISSN: 0022-9520
Volume: 45
Year: 1992
Pages: from 939 to 942
Number of references: 17
Language: engleski
Summary: One of the most important properties of the polymer is
itsmolecular structure and interaction intensity between solvent andpolymer
what also depends on that property. Interactionsintensity in each system
solvent-polymer can be described by theinteraction parameter, X. The
difference among preparedethylene-propylene-diene, EPDM, vulcanizate is in
the amount ofadded curative producing different crosslinking densities in
thepolymer. An attempt to describe network structure for elasticmaterials
requires, of course, information on the crosslingkingdensity interaction
parameter, X, and the crosslinking density,V, were determined by five
different methods for five types ofEPDM vulcanizates. The used methods
were: a) calculation of Vfrom the concentration of the curative, b)
"calibrating" thesample with a solvent to form a system for which X is
alreadyknown, c) stress-strain measurement and determination of
theMooney-Rivlin constant 2C, d) determination of the molecularweight
between crosslinking and e) the shear modulus, G,calculation.
Keywords: EPDM, Crossling density, Huggins parameter, Sweling, Stress-strain measurements
- Type of paper
: Paper in journal
Title: NETWORK CHARACTERIZATION OF ETHYLENE-PROPYLENE-DIENE
POLYMERS FROM STRESS-STRAIN AND EQUILIBRIUM SWELLING MEASUREMENT
- Authors:
- Hrnjak-Murgić, Zlata (120683)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
- Marović, Marijana
Journal: Kautsch.Gummi.Kunsts.
Number: 7
ISSN: 0022-9520
Volume: 46
Year: 1993
Pages: from 529 to 531
Number of references: 14
Language: engleski
Summary: Five samples of ethylene-propylene-diene, EPDM, containing
55wt-% ethylene, were prepared by peroxide curing. The networksthus formed
were highly random which suppose a complex structureand a broad
distribution of molecular weight. The networks werestudied with regard to
their stress-strain isotherms inelongation and their equilibrium swelling
in xylene at roomtemperature. Values of the elastic modulus 2C + 2C
obtained fromthe isotherms support theoretical assumption that the
junctionpoints in the network are firmly embeded in the network mediumand
values of the modulus 2C, show that the chain vectors wereconstrained in
their fluctuation even at large deformation.Values of the structur factor A
were calculated from theequilibrium swelling and show the same agreement
with he theoryas those of the elastic modulus.
Keywords: Ethylene-propylene-diene polymer, Equilibrium swelling, Network characterization, Stress-strain isotherms
- Type of paper
: Paper in journal
Title: PHOTOOXIDATIVE AGEING OF LOW DENSITY POLYETHYLENE
- Authors:
- Jelčić, Želimir (82275)
- Mlinac-Mišak, Marica (98560)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Journal: Angew.Makromol.Chem.
Number: 3522
ISSN: 0003-3146
Volume: 208
Year: 1993
Pages: from 25 to 38
Number of references: 16
Language: engleski
Summary: The efficiency of light stabilizers is investigated by
electricmethods in the initial stage of photooxidative ageing of lowdensity
polyethylene (LDPE). Three types of UV light stabilizersare tried to
improve the UV stability of LDPE: a phosphite
type(3,9-bis-((2,4-di-tert-butyl)phenoxy)-2,4,8,10-tetraoxa-3,9-diphosphasp
iro(5,5)undecane) a benzophenone type(2-hydroxy-4-octyloxy-benzophenone)and
stabilizer based onchelate salt (2,2-thiobis(4-tert-octyl
phenolato)(n-butylamine)nickel(II). LDPE is very susceptible to ultraviolet
light. UVlight stabilizers improve the stability of low densitypolyethylene
for electrical applications, especially the UVstabilizer based on chelate
salt.
Keywords: electric methods, photooxidative ageing, polyethylene low density, stability, UV-stabilizers.
- Type of paper
: Paper in journal
Title: THE INFLUENCE OF CYCLOHEXYLETHYLAMINE FACTICE ON THE
PROPERTIES OF ELASTOMERIC VULCANIZATES
- Authors:
- Opijač-Jovanović, Zlatija
- Jelenčić, Jasenka (41450)
- Wolf, Nikola (54274)
- Husar, Vladimir (106843)
- Bravar, Mladen (5281)
- Dabetić, Miomir (165790)
Journal: Plast. i guma
Number: 4
ISSN: 0351-8787
Volume: 11
Year: 1991
Pages: from 77 to 79
Number of references: 7
Language: hrvatski
Summary: The influence of the so-called amine factices on elastomers
wasexamined. Factice was made using reaction of hydrated soya oiland
sulphur with 2% cyclohexylethylamine and is used asvulcanization
accelerator. Factice was used in quantities of 10,21, 31 i 40 weight parts
to 100 parts of natural, styrenebutadiene and chloroprene rubbers.
Influences of factice onchanges of physical and mechanical properties of
vulcanizates,before and after ageing were investigated.
Keywords: Chloroprene rubber, Factice, Natural rubber, Rate of crosslinking, Styrenebutadiene rubber, Vulcanization.
- Type of paper
: Paper in journal
Title: THE INFLUENCE OF THE PART OF FILLERS AND SOFTENERS ON THE
PROPERTIES OF EPDM VULCANIZATES
- Authors:
- Petrov, Ivan
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Journal: Plast. i guma
Number: 2
ISSN: 0351-8787
Volume: 11
Year: 1991
Pages: from 41 to 44
Number of references: 24
Language: hrvatski
Summary: The influence of carbon black and oil ratio on some
rubberproperties of ethylene-propylene-diene rubbers (EPDM) have
beenexamined Effect of carbon black and oil ration on processing
andproperties of rubber mixtures and mechanical properties ofvulcanizates,
before and after ageing in warm air were examined.The optimum loading of
carbon black was determined from curecurves of loaded and unloaded EPDM
elastomers.
Keywords: Carbon black, EPDM rubber, Extrudability, Rubber properties.
- Type of paper
: Paper in journal
Title: THERMAL AND UV-DEGRADATION OF MODIFIED IMPACT-RESISTANT
POLYSTYRENE
- Authors:
- Jelenčić, Jasenka (41450)
- Mlinac-Mišak, Marica (98560)
- Parać, Ivan (192843)
- Bravar, Mladen (5281)
- Sišul, Nikica (43395)
Journal: Polimeri
Number: 1
ISSN: 0351-1871
Volume: 14
Year: 1993
Pages: from 3 to 6
Number of references: 14
Language: engleski
Summary: A commercial blended impact-resistant polystyrene, PS-HI,
wasinvestigated. It was modified withmethacrylate/butadiene/styrene, MBS,
in the amounts of 5, 10, 15,20 and 25 wt.% and stabilised with the
antioxidant Irganox 245.Films of 300 um tickness were thermally treated at
100 C for 7,14, 21, 28 and 35 days. Colour changes of dumbbells were
measuredon a Data Color 3890 apparatus, showing a change from the whiteto
the yellow area besause of the formation of double bonds.Measurements of
carbonyl and hydroxyl groups, as well aspolybutadiene unsaturation
absorbance were made by IRspectrophotometer.
Keywords: antioxidant, degradation, polystyrene, impact-resistant, thermal ageing, UV ageing.
- Type of paper
: Paper in journal
Title: THE INFLUENCE OF THE COMBINATION OF ACCELERATORS
ZINC-2-MERCAPTOBENZOTHIAZOLE/N,N-DIPHENYLGUANIDINE ON THE PROPERTIES OF NR
LATEX FILMS
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
- Biga, Nevenka (173401)
Journal: Polimeri
Number: 4
ISSN: 0351-1871
Volume: 14
Year: 1993
Pages: from 174 to 178
Number of references: 8
Language: hrvatski
Summary: It is necessary to define the optimal vulcanization system
inorder to get the vulcanizate of desired mechanical properties
andresistance in various ageing processes. The pater examines theinfluence
of the combination of accelerators ZnMBT/DPG (in masspropositions) on
natural rubber latex films. The films wereprepared by sulphur
vulcanization. The concentration ofaccelerators in the combination varied
from 0,75 to 1,50 phr.Tensile strength and elongation at break were
determined beforeand after thermal and UV ageing and ozone degradation.
Theresults show that the mechanical properties of unaged specimensattained
the optimum in the examined range of concentrations ofthe combination of
accelerators. Ozone degradation had the mostdestructive influence and the
greatest intensity of degradation.It proved almost independent of the
concentration ofaccelerators. The mechanical properties o thermal and UV
ageingfilms confirmed their different dependence on the concentrationof
accelerators, which points to different mechanisms governingthese
degradation processes.
Keywords: accelerators, ageing, mechanical properties, natural rubber, vulcanizate.
- Type of paper
: Paper in journal
Title: SULFAMIC ACID INHIBITION EFFECT ON CELLULOSE DEGRADATION
- Authors:
- Ilišković, Nadežda
- Bravar, Mladen (5281)
Journal: Cellulose Chem.Technol.
Number: 2
ISSN: 0576-9787
Volume: 26
Year: 1992
Pages: from 161 to 166
Number of references: 27
Language: engleski
Summary: Bleaching agents damage cellulose molecules to a certain
degree,causing its degradation. Chlorine and its compounds can beespecially
harmful. There is a group of substances which canreduce the degree of
cellulose degradation to some extent. Theseare mostly compounds with
amino-group, the sulfamic acid beingespecially distinguished among them.
Cellulose degradation isespecially present in the chlorination phase and
this work wasthis process. Combining different values of temperature, time
ofchlorination and bleaching agent quantity, as well as differentamounts of
sulfamic acid in the chlorination phase, theoptimal process conditions were
achieved. The best cellulosequality with regard to delignification degree,
brightness andviscosity was obtained when chlorination was carried out at
20,for 60 minutes with 70 % chlorine, with respect to the necesseryamount
and with 2-5 % sulfamic acid, with respect to chlorinepresent.
Keywords: bleaching agents, cellulose, chlorination phase, degradation, sulfamic acid.
- Type of paper
: Paper in journal
Title: THE OPTIMUM OF PAPER PRODUCTION IN THE PHASE OF GRINDING
- Authors:
- Turkalj, Dorothea (57180)
- Bravar, Mladen (5281)
- Ribičić, Josip
Journal: Acta graph.
Number: 3
ISSN: 0353-4707
Volume: 3
Year: 1991
Pages: from 119 to 128
Number of references: 11
Language: hrvatski
Summary: The sample of cellulose was prepared for investigation
ofinfluence of additives on the grinding process. The sample wasobtained
with the laboratory delignification of pine andfire-wood with percentage of
active alcaline. The obtainedcellulose was grinded without and with
additives of three dyes:C.I. Direct Red 28, C.I. Direct Blue 2 i C.I.
Direct Red 75during 15, 30, 45, 60 i 75 minutes. During laboratory process
thesheet papers were obtained. The physical and mechanicalproperties of
paper samples were measured. All the properties arebetter with the time of
grinding. All the additives increase thephysical and mechanical properties
of the cellulose.
Keywords: additives, cellulose, dyes, grinding process, physical and mechanical properties, paper.
- Type of paper
: Paper in journal
Title:
- Authors:
- Bajza, Željko (140705)
- Vuković, Tomislav
- Bravar, Mladen (5281)
- Kovačević, Vera (74041)
Journal: Koža i obuća
Number: 5
ISSN: 0450-8726
Volume: 1
Year: 1992
Pages: from 5 to 7
Number of references: 16
Language: hrvatski
- Type of paper
: Paper in journal
Title:
- Authors:
- Morović, Lj.
- Kovačević, Vera (74041)
- Bajza, Željko (140705)
- Mladinić, B.
Journal: Koža i obuća
Number: 3
ISSN: 0450-8726
Year: 1992
Pages: from 27 to 30
Number of references: 12
Language: hrvatski
- Type of paper
: Paper in journal
Title: THE EFFECT OF NEWLY SYNTHETIZED AGENT FOR FATTLIQUORING
AND BLEACHING ON LIGHT FASTNESS AND MECHANICAL PROPERTIES OF LEATHER
- Authors:
- Kovačević, Vera (74041)
- Mladinić, B.
- Marović, Marijana
- Bajza, Željko (140705)
- Čavara, Ž.
Journal: Koža i obuća
Number: 11
ISSN: 0450-8726
Year: 1992
Pages: from 125 to 127
Language: hrvatski
- Type of paper
: Paper in journal
Title: POSSIBILITY OF THE PROCESSING OF THE SHEEP SKINS
- Authors:
- Kovačević, Vera (74041)
- Bajza, Željko (140705)
- Babić, R.
Journal: Koža i obuća
Number: 9
ISSN: 0450-8726
Year: 1993
Pages: from 109 to 111
Number of references: 2
Language: hrvatski
- Type of paper
: Paper in journal
Title: THE SHOCK - ABSORPTION PHENOMENA IN ATHLETIC SHOE
- Authors:
- Agić, Ante (137300)
Journal: Periodicum Biologorum
Number: 1
ISSN: 0031-5362
Volume: 95
Year: 1993
Pages: from 185 to 188
Language: engleski
Summary: Many injuires in running are related to
insufficientshock-absorption properties of the shoes. A critical test
forshoes is how thev absorb the shock and transmit the force throughthe
body. Recently, improved sole design in running shoes haveconsiderably
reduced shock, through the use of modern foammaterials developed to act as
shock absorbers. It was found thatthe damping characteristics of the
foot-ground interaction playthe key role in reduction of the incoming shock
waves. Thequality of a shock isolation in the shoe is usually described bya
parameters curve as effeciency of energy absorption, shockspectra and
transmissibility matrix properties. Dynamic analysesof normal walking are
performed by measuring foot pressuredistributions. In this paper, a
mathematical modelling of theshock-absorption phenomena in the running
shoes withbiomechanical experiment validation in presented. This method
ofanalysis provides a powerful tool for the future design offootwear.
Keywords: shock isolation, shoe design
- Type of paper
: Paper in journal
Title: THE FENOMENOLOGICAL DESCRIPTION OF LEATHER STRENGHT
- Authors:
- Agić, Ante (137300)
- Bajza, Željko (140705)
Journal: Koža i obuća
ISSN: 0450-8726
Volume: 13
Year: 1991
Pages: from 255 to 264
Language: hrvatski
- Type of paper
: Paper in journal
Title: THE MORPHOLOGICAL CHANGES IN SEGMENTED POLYURETHANE UNDER
THERMAL TREATMENT
- Authors:
- Rek, Vesna (40741)
- Govorčin, Emi (127332)
Journal: Adv. Urethane Sci. Technol.
ISSN: 0044-6378
Volume: 11
Year: 1992
Pages: from 173 to 191
Number of references: 16
Language: engleski
Summary: Segmented polyurethane elastomers with approximately 50% by
wthard segment content were studied. Morphological changes inducedin these
polyurethanes by annealing and quenching wereinvestigated. The
morphological changes were followed bydifferential scanning calorimetry
(DSC) and dynamic mechanicalanalysis (DMA) as well as by static mechanical
measurements. Theannealling processes caused increased mixing of hard and
softsegments. The positions of the endotherms were changed as well asthe T
of PUR. This was reflected in the shifts of the lossmoduli and storage
moduli. This indicates that the domainmorphology is affected by thermal
treatment. There are alsochanges in mechanical properties. The hard and
soft segmentordering results in annealing endotherms that depend on the
typeof PUR, annealing temperatures and the time following the quench.
Keywords: polyurethane, morphological structures, annealing, quenching, phase mixing and separation, hard segment domeins, soft segment.
- Type of paper
: Paper in journal
Title: PHOTODEGRADATION OF POLYURETHANE
- Authors:
- Rek, Vesna (40741)
Journal: Adv. Urethane Sci. Technol.
ISSN: 0044-6378
Volume: 12
Year: 1993
Pages: from 134 to 165
Number of references: 31
Language: engleski
Summary: This chapter is a review of the investigations of
photooxidativedegradation of polyurethane, PUR. The mechanism of
photooxidativedegradation and secondary crosslinking reactions in PUR
arepresented. The course and the intensity of the changes inmolecular,
supermolecular and morphological structures of PUR dueto photooxidative
degradation are reviewed. These structuralchanges were followed by
comparative spectroscopic measurements(IR,NMR,UV), as well as by DSC
analysis, DMA, X-ray measurements,
electron microscopy and GPC measurements samples of PUR samplesbefore and
after various times of photooxidative degradation. Theinfluence of the
nature of the polyols and the isocyanatecomponents used in the syntheses of
PUR on the photodegradativeprocess and changes in PUR structures mentioned
above as well ason the rate of yellowing of PUR samples are discussed.
Thecorrelation between intensities of structural changes of PUR andits
mechanical properties are presented. The influence of thephysical state of
PUR and the thickness of the PUR samples on thephotooxidative stability of
PUR are also described.
Keywords: polyurethane, photodegradation, mechanism of photooxidative degradation, chemical structure, molecular mass, physical state of polyurethane, morphology structure, phase transitions, hard segment domains, soft segment, diisocyanate componente, dynamic mechanical spectras, mechanical properties.
- Type of paper
: Paper in journal
Title: FREE-RADICAL-INITIATED COPOLYMERIZATION OF
ALPHA-METHYLSTYRENE WITH MALEIMIDE
- Authors:
- Fleš, Dragan (68924)
- Vuković, Radivoje
- Kurešević, Vjera
Journal: Journal of Macromolecular Science Chemistry
Number: 10
ISSN: 0022-233
Volume: 28
Year: 1991
Pages: from 977 to 985
Number of references: 11
Language: engleski
- Type of paper
: Paper in journal
Title: COPOLYMERIZATION OF ALPHA-METHYLSTYRENE WITH
N-ALKYLMALEIMIDES
- Authors:
- Ranogajec, Franjo
- Fleš, Dragan (68924)
- Hace, Drago (15006)
- Vuković, Radivoje
Journal: Polymer Bulletin
ISSN: 1070-0839
Volume: 28
Year: 1992
Pages: from 319 to 325
Number of references: 16
Language: engleski
Summary: Alternating copolymers of alpha-methylstyrene (alpha-MeSt)
withN-alkylmaleimides (RMI); R=Et, n-Pr, iso-Pr, n-Bu, n-Hex) wereprepared
in Calvet differential microcalorimeter under differentmonomer-to-monomer
ratios in the feed using AIBN as initiator.The equilibrium constants of
CT-complex monomers have low values:0,02-0,05 L.mol but the mechanism of
copolymerization indicatesthe participation of CT-complex. Equilibrium
constants and rateof decomposition under the TGA conditions are not
dependent onsteric factors, but the rate of copolymerization decreases
withthe increase of bulkiness of alkyl substituent. In highconversion
copolymerization it was observed that in the presenceof an excess of
homopolymerizable RMI, alternating copolymersare quantitatively formed
prior to the formation of poly(RMI).
- Type of paper
: Paper in journal
Title: COPOLYMERIZATION OF ALPHA-METHYLSTYRENE WITH
4-N-(BENZO-15-CROWN-5) MALEIMIDE
- Authors:
- Fleš, Dragan (68924)
- Hace, Drago (15006)
- Ranogajec, Franjo
- Vuković, Radivoje
Journal: Polymer Bulletin
ISSN: 1070-0930
Volume: 29
Year: 1993
Pages: from 153 to 157
Number of references: 11
Language: engleski
Summary: 4-N-(Benzo-15-crown-5) maleimide (I) was prepared by
dehydrationof the corresponding maleamic acid (IV). The
complexationconstant, K=0.07 L mol, between I and
alpha-methylstyrene(alpha-MeSt) was determined by modified
Benesi-Hildebrand NMRmethod. The colopymerization of alpha-MeSt with
homopolymerizableI at different monomer-to-monomer ratios in the feed
wasperformed up to high conversion in Calvet microcalorimeter. Itwas found
that in the copolymerization of alpha-MeSt with excessof I, the alternating
copolymerization precedes thehomopolymerization. The mixture of alternating
copolymer andhomopolymer of I has a single Tg, thus indicating the
miscibilityon molecular level.
- Type of paper
: Paper in journal
Title: INORGANIC POLYMERS I
- Authors:
- Fleš, Dragan (68924)
- Hace, Drago (15006)
Journal: Polimeri
Number: 2
ISSN: 0361-1871
Volume: 13
Year: 1992
Pages: from 57 to 61
Language: hrvatski
- Type of paper
: Paper in journal
Title: INORGANIC POLYMERS II
- Authors:
- Fleš, Dragan (68924)
- Hace, Drago (15006)
Journal: Polimeri
Number: 3
ISSN: 0361-1871
Volume: 13
Year: 1992
Pages: from 93 to 100
Number of references: 15
Language: hrvatski
- Type of paper
: Paper in journal
Title: CROWN ETHERS IN POLYMER CHEMISTRY
- Authors:
- Fleš, Dragan (68924)
- Hace, Drago (15006)
Journal: Polimeri
Number: 4
ISSN: 0361-1871
Volume: 14
Year: 1993
Pages: from 169 to 173
Number of references: 26
Language: hrvatski
Summary: Examples of polymers and copolymers which contain crown
ethersare reviewed in the paper. The introduction points out that thisarea
of study is still in its infancy but that the uniqueproperties of both
crown ethers and polymers promise many usefulapplications and developments.
The paper describes crown ethersas modified in polymer reactions and
polymers which contain crowncompounds as parts of macromolecules.
Keywords: crown ether, as modifier of polymerization reactions, as parts of macromolecules.
- Type of paper
: Paper in journal
Title: STRUCTURE-PROPERTY RELATIONSHIPS IN
POLYURETHANE-POLY(STYRENE-CO-ACRYLONITRILE) BLENDS
- Authors:
- Žerjal, B.
- Musil, V.
- Šmit, Ivan
- Jelčić, Želimir (82275)
- Malavašić, Tatjana
Journal: Journal of Applied Polymer Science
ISSN: 0021-8995
Volume: 50
Year: 1993
Pages: from 719 to 727
Number of references: 15
Language: engleski
Summary: Blends of thermoplastic polyurethane (TPU)
andpoly(styrene-co-acrylonitrile) (SAN) (34% acrylonitrile and
24%acrylonitrile) and polyurethane ionomer (PUI) with SAN(34%acrylonitrile)
were prepared in the melt. The structuralproperties and morphology of the
blends were investigated. TPUand SAN blends were immiscible in the
composition range 30-70%wtof TPU or SAN. In TPU-rich blends, SAN propagates
the separationof hard and soft segments in TPU. In SAN-rich blends,
theinteraction stage depends on acrylonitrile contents. SEMmeasurements
showed that the blends of TPU/SAN were finedispersions and clearly showed a
continous and dispersed phase,whereas the morphology of the PUI/SAN blends
were different.
Keywords: Thermoplastic polyurethane, Styrene-Acrylonitrile copolymers, Blends, Structural Properties, Morphology.
- Type of paper
: Paper in journal
Title: MECHANICAL PROPERTIES OF THERMOPLASTIC POLYURETHANE BLENDS
AND COPOLYMERS OF STYRENE AND ACRYLONITRILE
- Authors:
- Žerjal, B.
- Musil, V.
- Jelčić, Želimir (82275)
- Šmit, Ivan
- Malavašić, Tatjana
Journal: International Polymer Processing VII
ISSN: 0930-777
Year: 1992
Pages: from 123 to 125
Number of references: 3
Language: engleski
Summary: Mechanical data obtained on the blends described in a
previouspaper together with some new data have been correlated with
thetheory derived for the mechanical properties of polymercomposites, to
gain insight into the nature of domaininterfaces, thermoplastic
polyurethanes are blended in the entirecomposition range, with
styrene-acrylonitrile copolymers.Blending with thermoplastic polyurethanes
improves the toughness.Improved toughness is indicated by the increase of
elongation atbreak and by decrease of hardness.
Keywords: Thermoplastic polyurethane, Styrene-Acrylonitrile copolymers, Blends, Mechanical Properties.
- Type of paper
: Paper in journal
Title: THERMALLY STIMULATED CURRENT IN GLASS-LAMINATED
UNSATURATED POLYESTER RESINS
- Authors:
- Jelčić, Želimir (82275)
- Ranogajec, Franjo
- Babić, Lenija
- Ivanković, Z.
Journal: International Polymer Processing VII
Volume: 12
Year: 1991
Pages: from 384 to 390
Number of references: 7
Language: engleski
Summary: Experimental results are reported on the electrical
properties ofglass-laminated unsaturated polyester (UP) resins.
Measurementsof the poling current as a function of temperature reveal
twodifferent activated processes. Above 50 C the activation energyis 160
kJ/mol and has been associated with ionic conduction,possibly by protons,
while at lower temperature (below -70 C) theactivation energy is very low
(less than 40 kJ/mol) andassociated with dipole relaxation. It is concluded
that thelaminated UP resin undergoes a phase transformation between lowand
high temperatures which gives rise to a completely differentelectrical
response. This phase transformation can be associatedwith the glass
transition of UP resin phase. In view of the lowactivation energy-giving
rise to a polarization peak it isconcluded that the low temperature range
(glassy state) favoursstrictly localized motions of charges - most likely
electrons. Athigher temperatures, the behaviour corresponds to
d.c.conductivity and is associated with extended motions of chargecarriers
with limitations at contacts and at internal barriers.According to the air
gap measurements the pronounced dip found inthe temperature dependence of
the poling current (in the rangefrom 20 to -30 C) may be due to separation
of conduction anddipole relaxation current. Thermaly stimulated
depolarization(TSD) current measurements reveal the presence of high
internalfields due to space charges accumulated at the phase boundariesof
glass fibers.
Keywords: Thermally stimulated current, composites, unsaturated polyester resin.
- Type of paper
: Paper in journal
Title: DIELECTRIC SPECTROSCOPY AND THERMALLY STIMULATED
DEPOLARIZATION OF PLASTICIZED POLY(VINYL CHLORIDE)
- Authors:
- Jelčić, Želimir (82275)
- Brajković, N.
Journal: Polimeri
ISSN: 0351-1871
Volume: 13
Year: 1992
Pages: from 183 to 189
Number of references: 13
Language: hrvatski
Summary: Compounding and phase behaviour of poly(vinyl chloride)
compoundswith di-octyl phtalate and chalk is determined by
measuringdielectric permittivity, conductivity and thermally
stimulateddepolarization. The correlation of measured values andcomposition
and temperature is determined. The content of theplasticizer and filler has
a marked influence on all of theproperties. Plasticizer shifts the
relaxation spectrum to highertemperatures, and the filler to lower one.
Measurements accordingto standards ion one point is not enough to determine
thebehavior of compound. The relaxation spectrum should bedetermined in
wide temperature and frequency range.
Keywords: Poly(vinyl chloride), plasticized, filler, dielectric spectroscopy, thermally stimulated depolarization.
- Type of paper
: Paper in journal
Title: OPTIMIZATION OF PLASTICIZED POLY(VINYL CHLORIDE) SYSTEMS
- Authors:
- Jelčić, Želimir (82275)
- Brajković, N.
- Perčulija, I.
Journal: Polimeri
ISSN: 0351-1871
Volume: 13
Year: 1992
Pages: from 69 to 73
Number of references: 4
Language: hrvatski
Summary: The effect of additives on physical properties of
poly(vinylchloride) (PVC) mixtures with the plasticizer (di-octylphtalate)
and filler is determined by measuring density,elongation and strength at
break, hardness, dielectricpermittivity and conductivity. The correlation
of measuredproperties and composition is determined. Calculated and
measuredproperties have been compared. The content of the plasticizer hasa
marked influence on the all properties.The filler influencesonly the
density.
Keywords: Poly(vinyl chloride), plasticized, properties and composition correlation.
- Type of paper
: Paper in journal
Title: ULTRAVIOLET DEGRADATION OF NATURAL REUBBER LATEX FILMS
VULCANIZED WITH DIFFERENT ACCELERATORS
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
- 0, 0
Journal: Polimeri
Number: 4
ISSN: 0351-1871
Volume: 15
Year: 1994
Pages: from 119 to 122
Number of references: 10
Language: engleski
Summary: Natural rubber latex films were prepared by sulphur
vulcanization. Four different accelerators were used: diphenulguanidine,
zinc-2-mercaptobenzothiazole, their combination, and
zinc-diethyldithiocarbamate. The influence of photooxidation on the
physical properties of natural rubber is very complex. It is necessary to
consider the characteristics of the different sulphur crosslink structures,
degradation reactions during ageing, as well as the process of
crystalization that occurs at higher extension ratios. In this work, the
chemical and physical changes of vulcanizates during UV ageing were
studied. The results show that different types of accelerators formed
different crosslink structures. These structures influence changes in the
vulcanizate properties during photooxidation.
Keywords: accelerators, natural rubber, UV ageing
- Type of paper
: Paper in journal
Title:
- Type of paper
: Paper in journal
Title:
- Type of paper
: Paper in journal
Title:
- Authors:
- Skansi, Darko
- Bajza, Željko (140705)
- Arapović, A.
- Type of paper
: Paper in proceedings
Title: DECOMPOSITION OF SODIUM PERBORATE WITH TAED AS ACTIVATOR
- Authors:
- Wolf, Nikola (54274)
- Gomzi, Zoran
Proceedings title: Zbornik radova prvog simpozija hrvatskog društva za tenzide
Language: hrvatski
Place: Rovinj, Hrvatska
Year: 1993
Pages: from 98 to 0
Meeting: Prvi simpozij hrvatskog društva za tenzide
Held: from 05/25/93 to 05/27/93
Summary: Decomposition of sodium perborate has been investigated in
thesolution of detergent without and with (0 - 5%) TAED as activatorat
temperature from 40 to 90 C. Kinetic model of decomposition ofNa-perborate
in alkaline solution was proposed and theexperimental data were tested to
this model. At the lowerreaction with TAED, followed by the formation of
activated oxygenfrom peracetic acid. At the higher temperatures (>80 C),
activeoxygen is deliberated mainly by the reaction of decomposition
ofsodium perborate through the formation of hydroxyl anione.
- Type of paper
: Paper in proceedings
Title: STUDY OF RHEOLOGICAL BEHAVIOUR OF COMPLEX DETERGENT SLURRY
- Authors:
- Hace, Drago (15006)
- Špehar, Zdravko
- Wolf, Nikola (54274)
Proceedings title: Zbornik radova prvog simpozija hrvatskog društva za tenzide
Language: hrvatski
Place: Rovinj, Hrvatska
Year: 1993
Pages: from 215 to 0
Meeting: Prvi simpozij hrvatskog društva za tenzide
Held: from 05/25/93 to 05/17/93
Summary: Investigations have been carried out in order to show
differentinfluence of dry contents, temperature, hydrotropic salt
additionand substitution of phosphate with zeolite on rheologicalbehaviour
of detergent composition. The flow curve approximationwith power law
Ostwald-de Waele by means of linear regressionanalyses using computer
showed a good correlation of the measuredvalues. Preliminary rheological
investigations was made toevaluate the stabilization effect of dispersants
polyelectrolytesor surfactants on 40% water suspension of zeolite.
- Type of paper
: Paper in proceedings
Title: EMULGATORS OF CARBOHYDRATES AND SORBITOLS LONG-CHAIN FATTY
ACID
- Authors:
- Giacometti, Jasminka
- Milin, Čedomila
- Wolf, Nikola (54274)
- Sišul, Nikica (43395)
Proceedings title: Zbornik radova prvog simpozija hrvatskog društva za tenzide
Language: hrvatski
Place: Rovinj, Hrvatska
Year: 1993
Pages: from 343 to 0
Meeting: Prvi simpozij hrvatskog društva za tenzide
Held: from 05/25/93 to 05/27/93
Summary: Importance, physical and chemical properties of
nonionic,biological degradable surfactans consisted long-chain fatty
acid,are described. This group of surfactans is made of mono- anddisorbitan
esters mixture and carbohydrates esters. Sorbitolesters as emulsifiers of
the W/O type appear under the nameSpan,s, emulsifiers of the O/W type. The
compounds of this typehave their application in stability of hormones,
fats, vitaminesand antibiotics. They can be used as stabilizers of the
emulsionsand suspensions, or as additives in the quantity of the
extractedsubstances.
- Type of paper
: Paper in proceedings
Title: THERMAL POLYMERISATION AND ITS EFFECTS ON TUBULAR REACTOR
FOR ETHYLENE HP POLYMERISATION
- Authors:
- Grković, Veljko (151781)
- Blažeković, Ivan
Proceedings title: ELF ATOCHEM 1992 European LDPE Producers Safety Conference
Language: engleski
Place: Paris, Francuska
Year: 1992
Pages: from 1 to 16
Meeting: European LDPE Producers Safety Conference
Held: from 05/21/92 to 05/22/92
Summary: The effect of "dead spots" which are free of motion on
thereaction mixture, on frequency of decomposition in tubularreactor is
given.
The areas with a stationary reaction mixture may originate fromthe
construction error or fault in the course of the reactor,sinstallation
(close to flanges or at lateral gas entranes) or arefound in the areas
damaged due to long-standing exploatation. Insuch an area, a self
accelerated thermal polymerisation ispossible which results in a
decomposition of the reactionmixture.
The minimum diametar of the "dead spot" having of a cylinder andsphere at
given reaction condition and the "time - to -decomposition" in the designed
volume of the reaction mixture iscalculated.
- Type of paper
: Paper in proceedings
Title: OPTIMUM SHOCK ISOLATION
- Authors:
- Agić, Ante (137300)
Proceedings title: Structural Dynamics
Language: engleski
Place: Rotterdam, Nizozemska
Year: 1991
ISBN/ISSN: 906191 1680
Pages: from 245 to 250
Meeting: European conference on structural dynamics
Held: from 07/05/90 to 07/07/90
- Type of paper
: Paper in proceedings
Title: HYPERELASTIC BEHAVIOUR OF LARGE BLOOD VESSELS
- Authors:
- Miović, B.
- Agić, Ante (137300)
Proceedings title: Topics on Biomathematics
Language: engleski
Place: Singapore, Singapore
Year: 1993
Pages: from 151 to 160
Meeting: The World Committe for Biomechanics
- Type of paper
: Paper in proceedings
Title: MODELLING OF THE CHEMICAL DEGRADATION IN POLYMERS
- Authors:
- Agić, Ante (137300)
Proceedings title: Numerical Methods in Thermal Problems
Language: engleski
Place: Stanford, Engleska
Year: 1991
Pages: from 1440 to 1450
Meeting: Numerical Methods in Thermal Problems
Held: from 07/08/91 to 07/12/91
- Type of paper
: Paper in proceedings
Title: A FINITE ELEMENT ANALYSIS OF AGEING PROCESSES IN POLYMERS
- Authors:
- Agić, Ante (137300)
Proceedings title: Proceedings of Nonlinear Engineering Computations 91
Language: engleski
Place: Swansea, Engleska
Year: 1991
Pages: from 721 to 729
Meeting: Proceedings of Nonlinear Engineering Computations 91
Held: from 09/16/91 to 09/20/91
- Type of paper
: Paper in proceedings
Title: LEATHER MICROMECHANICS
- Authors:
- Bajza, Željko (140705)
- Vuković, Tomislav
- Agić, Ante (137300)
Proceedings title: Compedium of Advances Topics on Leather Technology
Language: engleski
Place: Barcelona, Španjolska
Year: 1991
Pages: from 1141 to 1149
Meeting: XXI Congress of the I.U.L.T.C.S.
- Type of paper
: Paper in proceedings
Title: PHOTOSTABILITY OF POLYURETHANE ELASTOMERS BASED ON VARIOUS
TYPES OF DIISOCYANATES
- Authors:
- Rek, Vesna (40741)
- Govorčin, Emi (127332)
- Sendijarević, Aiša
- Sendijarević, Vahid
- C. Frisch, Kurt
Proceedings title: 34th Annual Polyurethane Conference
Language: engleski
Place: New Orleans, U S A
Year: 1992
Pages: from 618 to 628
Meeting: Annual Polyurethane Conference
Held: from 10/21/92 to 10/24/92
Summary: The effect of UV irradiation on the mechanical
andthermomechanical properties of polyurethane (PU) elastomers andtheir
morphology was studied. The chemical changes in the PUelastomers exposed to
UV radiation were studied by means ofFourier Transform Infrared
Spectroscopy (FTIR). The PU elastomerswere based on as aromatic isocyanate
(4,4-diphenylmethanediisocyanate) and a cycloaliphatic
isocyanate(4,4-dicyclohexylmethane diisocyanate). Poly(caprolactone)
glycolof 1250 molecular weight was the polyol used and 1,4-butanediolwas
the chain extender. The elastomers were prepared in a twostep procedure.
First, prepolymers were prepared frompoly(caprolactone) glycol by reacting
with the correspondingisocyanate at NCO-OH ratios of 2:1 and 4:1. The
perpolymers werethen chain-extended with 1,4-butanediol and the mixtures
werepress-molded in a platen press at 100 C. The results showed thatthe
stability of the investigated PU elastomers depended on thechemical
structure of the diisocyanate and the hard/soft segmentratio. The processes
of photooxidative degradation are moreprevalent in PU elastomers based on
the cycloaliphatic isocyanatethan those based on the aromatic isocyanate.
In the case of PUelastomers based on the cycloaliphatic isocyanate it was
foundthat the photodegradative processes were enhanced with increasinghard
segment concentration. The degree of photooxidativedegradation of PU
elastomers, as studied by FTIR, correlated verywell with the extent of
morphological changes and changes inmechanical properties. Although PU
elastomers based on thearomatic isocyanate undergo color changes, they
exhibited betterretention of mechanical properties compared to those based
onthe aliphatic isocyanate.
Keywords: polyurethane, isocyanate component, aromatic isocyanate, cycloaliphatic isocyanate, photodegradation, morphology, relaxation spectra, mechanical properties.
- Type of paper
: Paper in proceedings
Title: CHEMICAL AND THERMAL DEGRADATION OF HIGH IMPACT
POLYSTYRENE IN AGGRESSIVE ACID MEDIUM
- Authors:
- Hace, Drago (15006)
- Kovačević, Vera (74041)
Proceedings title: Stirenski plastomeri
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 83 to 90
Meeting: Stirenski plastomeri
Held: from 06/27/91 to 06/28/91
Summary: High impact polystyrene (PS-HI) is subjected to the action
ofconcentrated nitric acid for a period of 1 to 8 hours at 40 C, 70C and 80
C respectively. Because of the surface action of theaggressive medium,
significant changes in mechanical, structuraland morphological properties
determined for two types of polymersoccur. The effect of the initial
polymer morphology on thethermochemical and degradation processes is
established.
Keywords: high impact polystyrene, aggressive medium, nitric acid, thermochemical degradation, structural and morphological changes of polystyrene
- Type of paper
: Paper in proceedings
Title: A DIELECTRIC INVESTIGATION OF POLYURETHANE /
POLY(STYRENE-CO-ACRYLONITRILE) BLENDS
- Authors:
- Žerjal, B.
- Jelčić, Želimir (82275)
- Šmit, Ivan
- Musil, V.
- Malavašić, Tatjana
Proceedings title: Fourth European Symposium on Polymer Blends
Language: engleski
Place: Capri, Italija
Year: 1993
Pages: from 227 to 230
Meeting: Fourth European Symposium on Polymer Blends
Held: from 05/24/93 to 05/26/93
Summary: The dielectric permittivity, the dielectric loss and
thedielectric loss tangent of
polurethane(TPU)/poly(styrene-co-acrylonitrile) (SAN) blends have
beenstudied, dielectric measurements have shown that the
relaxationprocesses in TPU/SAN blends occur at the same temperature as
therelaxation processes in pure components. This is consistent withthe
immiscible nature of the blends. The addition of TPU to SANproduces a
plasticizing effect at very low concentrations.
Keywords: Thermoplastic polyurethane, styrene-acrylonitrile copolymers, blends.
- Type of paper
: Paper in proceedings
Title: MODIFICATION POLYSTYRENE WITH
POLYSTYRENE-BLOCK-POLYBUTADIENE COPOLYMER
- Authors:
- Mlinac-Mišak, Marica (98560)
- Jelčić, Želimir (82275)
- Janović, Zvonimir
Proceedings title: Stirenski plastomeri
Language: hrvatski
Place: Zagreb
Year: 1991
ISBN/ISSN: 86-7483-010-2
Pages: from 91 to 95
Meeting: Stirenski plastomeri
Held: from 06/27/91 to 06/28/91
Summary: The incorporation of a rubber phase in glassy polymer, as
is wellknown in the case of high impact polystyrene (HIPS), leads to
anincrease in their impact strength. The opacity of HIPS precludesits use
in applications requiring transparency. Block copolymersoffer new
approaches for obtaining multiphase polymers in whichan elastomer phase is
present in the matrix of polystyrene and inmost cases such systems besides
higher impact strength showappreciable tranparency. In the present study,
the preparationand properties are discussed for polymer blends obtained
bycombining polystyrene and SB block copolymers. Mechanicalproperties of
glass clear polystyrene are determined by the totalrubber phase volumes
indicating certain contribution of blockpolystyrene to that phase and
producing an improvement incorrelation with mechanical properties with
respect to the totalpolybutadiene alone.
Keywords: polystyrene, styrene-butadiene copolymer, blends.
- Type of paper
: Paper in proceedings
Title: POLYSTYRENE AND STYRENE-BUTADIENE COPOLYMERS, MIXTURES,
BLENDS, ALLOYS
- Authors:
- Jelčić, Želimir (82275)
Proceedings title: Stirenski plastomeri
Language: engleski
Place: Zagreb
Year: 1991
ISBN/ISSN: 86-7483-010-2
Pages: from 31 to 35
Meeting: Stirenski plastomeri
Held: from 06/27/91 to 06/28/91
Summary: Reasons for polymer blending, their properties, economy
andmarket is described. The earliest types of blends were preparedby using
natural miscibility of the components. Blends ofhomopolymer were recently
developed using graft or blockcopolymers.
Keywords: Polystyrene, styrene-butadiene copolymer, mixtures, blends, alloys.
- Type of paper
: Paper in proceedings
Title: INVESTIGATION OF THE INORGANIC FILLERS INFLUENCE ON THE
PROPERTIES OF POLY(VINYL ACETATE) ADHESIVES
- Authors:
- Kovačević, Vera (74041)
- Lučić, Sanja
- Hace, Drago (15006)
- Glasnović, Antun (13493)
- Šmit, Ivan
- Bravar, Mladen (5281)
Proceedings title: The Adhesive Society
Language: engleski
Place: Williamsburg, Engleska
Year: 1993
ISBN/ISSN: 93-070199
Pages: from 297 to 300
Meeting: The Sixteenth Annual Meeting
Held: from 02/21/93 to 02/26/93
Summary: The paper presents the results of the investigations about
theinfluence of various kinds of inorganic fillers based on
calciumcarbonate and alumosilicate as well as of the reference strachfiller
on adhesive properties of poly(vinyl acetate) composition.The filler were
characterized by chemical composition, particlesize distribution, surface
area and crystalline structure. Therheological behaviour of poly(vinyl
acetate) adhesiveconcerning the specific role of the structural and
morphologicalparameters of the filler. The mechanical properties of
theprepared films of poly(vinyl acetate) adhesives containing thedefined
amounts of selected fillers were determined. Theinfluences of the fillers
on the strength characteristics of thewood adhesive joint were also
studied. The results definitelyestablished that fillers particle size
distribution along withtheir other characteristics may exert considerable
influence onthe adhesive properties of the poly(vinyl acetate)
compositions.
Keywords: poly(vinyl acetate) adhesive composition, inorganic filler, calcium carbonate, alumosilicate, characteristic of filler, rheology of adhesive.
- Type of paper
: Paper in proceedings
Title: THE ROLE OF RUBBER PRODUCTS DURABILITY IN MARINE
ENVIRONMENT AGEING CONDITIONS
- Authors:
- Bravar, Mladen (5281)
- Jelenčić, Jasenka (41450)
- Markovčić, Nada
- Hell, Zvonimir
Proceedings title: Sorta 94'
Language: hrvatski
Place: Dubrovnik
Year: 1994
Pages: from 191 to 200
Meeting: XI Simpozij teorija i praksa brodogradnje
Held: from 05/19/94 to 05/21/94
Summary: This overview presents and discusses isssues with numerous
dilemmas and difficulties arisingf in the course of the selection of a
reliable elastomeric materials for the production of structural parts and
products in shipbuilding. The existing lack of materials and product
standardization concering the durability in service in marine environment
may be paretly compensated by considering and reasonably using the novel
findings obtained in outdoor terrestrial environmental ageing and in
accelerated laboratory tests. The need for establishing the real marine
environment polymer ageing experiments and simulating them appears as s
required assignment of materials scientists in naval architecture and
shipbuilding.
Keywords: rubber, ageing of polymers, marine environment
- Type of paper
: Paper in proceedings
Title: EFFECT OF POLYMER-FILLER ADHESION ON THE FILM PROPERTIES
OF POLY(VINYL-ACETATE) ADHESIVES FILLED WITH CALCITE FILLERS
- Authors:
- Kovačević, Vera (74041)
- Lučić, Sanja
- Hace, Drago (15006)
Proceedings title: Dani plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from 87 to 94
Meeting: 13 Dani društva plastičara i gumaraca
Held: from 09/26/95 to 09/29/95
Summary: The mechanical properties of film adhesives depend verz
strong on the degree of interfacial bond developed between
poly(vinyl-acetate) polymer matrix and calcite filler. In the present paper
tensile properties were evaluated in the composition range 0-15 wt %
calcite, along with filler surface modifications with stearic acid. State
of dispersion of the filler in the polymer matrix has been analyzed by
studying the morphology of the adhesive films with the help of scanning
electron microscopy. Tensile strength increased with filler concentration,
while breaking elongation decreased. The tensile increase was attributed to
the increase of adhesion between polymer and filler. Generation of
discontinuity in adhesive film structure through formation of stress
concentration points accounted for breaking elongation decrease and
relative tensile strength decrease, when very coarse filler particles were
present. The tensile breaking strength data were analysed usign some models
in orther to understand the generation of discontinuity or weakness in the
structure of two-phase adhesive films. Breaking elongation improvement of
adhesive films depend on the effectiveness of the coupling agent in the
optimisation work of adhesion, wetting ability of the polu(vinyl-acetate)
and, as a result, lowering the freee surface energy of the interface.
Keywords: poly(vinyl acetate)(PVAC) adhesive, composite PVAC matrix/CaCO3 filler, adhesion, mechanical properties of film
- Type of paper
: Paper in proceedings
Title: LOW DENSITY POLYETHYLENE RHEOLOGICAL MEASUREMENTS
- Authors:
- Jelčić, Želimir (82275)
Proceedings title: Dani plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from 42 to 47
Meeting: 13 Dani društva plastičara i gumaraca
Held: from 09/26/95 to 09/29/95
Summary: Polymer melts are viscoelastic, non-Newtonian fluids, whose
viscosity and elasticity depend on the shear rate, i.e. on the rotational
frequency of rotors or screws. The effect of polyethelene type, molecular
structure and melt flow rate on the results of measurement on the different
rheological equipment is studied. Mixer gives relatively high viscosity
values, and it is suitable for high shear, turbulent flow and high
temperature; and for determination of chemical and physical changes,
degradation and crosslinking. Extruder capillary rheometer make available
measurements of sluidity and viscosity curves by medium and high shear
rates. Rotational rheometer make possible to determine the viscoelastic
properties and to determine the polymer relaxation-spectrum. Rotational
rheometers can perform measurements in wide frequency range, and this
result combined with the capillary measurements gives very wide shear rate
range.
- Type of paper
: Paper in proceedings
Title: VISCOELASTIC BEHAVIOR OF THE DEGRADABLE POLYMERS
- Authors:
- Agić, Ante (137300)
- 0, 0
Proceedings title: Dani plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from 58 to 61
Meeting: 13 Dani društva plastičara i gumaraca
Held: from 09/26/95 to 09/29/95
Summary: The complex behavior and structure of the nonlinear
continuua have described on the best way by the internal variable's
formalism. The generalized stress-strain constitutive equations for
degradable viscoelastic continuua have developed by use this theory. The
behaviors of the material have uniquely defined by the structure of the
free energy and evolution equations for internal coordinates (constitutive
equations on the microscopis level). The equivalent microscopic behavior as
accompanied degradation mechanism has described by set of internal
variables (free volume, viscous damping, domage, crosslink density). The
nonlinear behavior has described by three thermodynamics tensor functions
and by generalized shift factors. Some experimentally detected anomaly
under degradative environment5 can be explained by proper microstructure's
models.
- Type of paper
: Paper in proceedings
Title: INVESTIGATION OF ADHESIVE AND ADHESIVE BONDS PROPERTIES IN
DEGRADATION CONDITIONS
- Authors:
- Kovačević, Vera (74041)
- Lučić, Sanja
- Hace, Drago (15006)
- Cerovečki, Željko (17973)
Proceedings title: Od uzorka do podataka informacije
Language: hrvatski
Place: Zagreb
Year: 1995
Meeting: CROSS
Summary: In the paper an overview of investigations the adhesive
systems based on PUR, CCl i PVAC was given. The results showed that
adhesive composition and the separate components had significant influence
on adhesive properties and quality characteristics.
Keywords: adhesives, composition and components, adhesive quality
- Type of paper
: Paper in proceedings
Title: CONTROLLED PHOTODEGRADATION OF POLYETHYLENE
- Authors:
- Mlinac-Mišak, Marica (98560)
- Jelčić, Želimir (82275)
- Jelenčić, Jasenka (41450)
- Božić, Dražen
Proceedings title: Dani plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from 62 to 66
Meeting: 13 Dani društva plastičara i gumaraca
Held: from 09/26/95 to 09/29/95
Summary: Photodegradable polystyrene was prepared by addition of
organic metal salts which enhance photooxidative degradation of
polystyrene. By addition of UV stabiliyers, photodegradative process was
controlled. Laboratory testing of enhanced photooxidative degradation of
polystyrene by ultravioletic light was proceed in Xenotest chamber.
Enhanced photooxidative degradation, mixture of polystyrene and organic
metal salts, was confirmed by observation of carbonyl index variation,
yelowing index and dielectric properties.
- Type of paper
: Paper in proceedings
Title: SYSTEM OF PROJECTING SHOES
- Authors:
- Agić, Ante (137300)
Proceedings title: Informacijski sustavi IS 95'
Language: hrvatski
Place: Varaždin
Year: 1995
Pages: from B7-13
Meeting: 6 Međunarodni Simpozij IS 95'
Held: from 09/11/95 to 09/13/95
- Type of paper
: Paper in proceedings
Title: EXPERIMENTAL EVALUATION OF MICROWAVE DRYING OF LEATHER
- Authors:
- Skansi, Darko
- Bajza, Željko (140705)
- Arapović, A.
Proceedings title: XXIII IULTCS CONGRESS
Language: njemački
Place: Friedrichshafen, Njemačka
Year: 1995
Meeting: XXIII IULTCS CONGRESS
Held: from 05/15/95 to 05/20/95
Summary: Das Mikrowellentrocken von industriell vorbereitem Leder in
den Laboratoriums mabstab experimentell erfoscht. Man fuhrte die
Experimente auf drei vershiedenen Studfen der Mikrowellenheizung. In dem
die Masse des Probekorpers wahrend Dauer des Trockensverfahrens gemessen
wurde, hat man kinetische Trockenkurven erhalten. Zwecks korrelation von
Experimentalresultaten wurden das Exponentialmodell und seine X-(a-Xeq).exp
(-b.td)-Xeq verschiedenen Formen angewandt. Die erzielten Resultate weisen
eine Hochkorrelation und hohe Abhangigkeit wwischen der angewandeten
Mikrowellenstarke und Dauer des Trockenszerfahrens, des Ledertype so wied
ihrem Vorbearbeitung (Vakuum und seitenwisen Wasserablub).
Keywords: trocknen, kinetisch, leder, mikrowellenheizung
- Type of paper
: Paper in proceedings
Title: DIE VERSCHIEDENEN MOGLICHKEITEN OKOLOGISCH ANNEHMBARER
LEDERHERSTELLUNG
- Authors:
- Bajza, Željko (140705)
- Bravar, Mladen (5281)
- Agić, Ante (137300)
Proceedings title: XXIII IULTCS CONGRESS
Language: njemački
Place: Friedrichshafen, Njemačka
Year: 1995
Meeting: XXIII IULTCS CONGRESS
Held: from 05/15/95 to 05/20/95
Summary: Vorschriften uber das Klared der Abwasser und ihrer
Bearbeitung, bzw. uber das Deponieren der Abfalle weisen auf die
Verpflichtung des Anpassungsprozesses der Lederherstellung auf. Besonders
streng sind die chrommengen reguliert und es werden immer mehr die
Moglichkeiten der Einfuhrung der alternativen Gerbenmethoden gepruft wie
z.B. die Einfuhrung der andereren mineralischen, pflanzlichen oder
synthetischen Gerbmittel. In dieser Arbeit wurde das Gerbprozeb mit den
Chromsalzen durchgefuhrt, weiter mit den Aluminiumsalzen, mit dem
Aldehydgerbe, pflanzlichenm Gerbe und synthetischem Gerbe. Die Experimente
wurden an Rindleder mit dem Salzen der Gewichtskategorei 25-30 kg
durchgefuhrt. Es wurden chemische, physikal-mechanische und thermische
Untersuchungen der Fertigleder gemacht. Es wurden auch Abwasser pH
untersucht, de4r chemische Sauerstoffverbrauch und die chrommenge.
Gleichzeitig wurden die Lederuntersuchungen in verschiedenen Phasen der
Herstellung gemacht vom rohen, geascherte, nachgerbenden bis fertigem
Leder.
- Type of paper
: Summary in proceedings
Title: THE INFLUENCE OF ACCELERATOR
Zn-2-MERCAPTOBENZOTHIAZOLE/N,N-DIPHENYLGUANIDINE TO THE PROPERTIES OF NR
LATEX FILMS
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
- Biga, Nevenka (173401)
Proceedings title: XII Skup hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 344 to 0
Meeting: XIII Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
- Type of paper
: Summary in proceedings
Title: NETWORK CHARACTERIZATION OF ETHYLENE-PROPYLENE-DIENE
POLYMER FROM STRESS-STRAIN AND EQUILIBRIUM SWELLING
- Authors:
- Hrnjak-Murgić, Zlata (120683)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Proceedings title: XIII Skup hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 343 to 0
Meeting: XIII Skup hrvatskih kemičara
Held: from 02/08/93 to 02/10/93
- Type of paper
: Summary in proceedings
Title: DETERMINATION OF POLYMER-SOLVENT INTERACTION PARAMETERS OF
ETHYLENE-PROPYLENE-DIENE RUBBER VULCANIZATES IN DIFFERENT SOLVENTS
- Authors:
- Hrnjak-Murgić, Zlata (120683)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 63 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: Two types of ethylene-propylene-ethylidiene norbornene
rubbers,EP-ENB, differing in ethylene contents, 55 and 65 wt.%,
havingethylidene norbornene content 4,0 wt.% were vulcanized by
dicumylperoxide, DCP at 4-8 phr levels in the presence
ofacetaldehyde-aniline condensation product as accelerator. Thevulcanizates
were defined by physical and mechanical properties.Polymer-solvent
interaction parameters, X were determined byequilibrium swelling method and
by tensile stress-strainmeasurement. About twenty solvents were in the
experiments. Theobtained data were compared and discussed with that found
in theliterature in similar investigations. Interaction parameters
wereobserved to differ according to the determination method. Thisevolved
to pronounced difficulties at EP-ENB of lower networkdensities, particulary
in strong swelling media. A carefulselection an scrutiny of experimental
data an of the literatureones would be required for the elaboration of the
conceptions ofpolymer network density.
- Type of paper
: Summary in proceedings
Title: SOME PECULIAR CHARACTERISTICS OF LOW DENSITY POLYETHYLENE
AFTER UV AGEING
- Authors:
- Jelenčić, Jasenka (41450)
- Dabetić, Miomir (165790)
- Mlinac-Mišak, Marica (98560)
- Jelčić, Želimir (82275)
- Bravar, Mladen (5281)
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 76 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 02/18/92
Summary: Low density polyethylene, LPD, OKITEN F 20 RZA was used
forphotostability and thermal oxidation resistance
studies.Benzophenone-type UV stabiliser CHIMASSORB 81 and the phosphite
-type antioxidant ULTRANOX 626 were used in combinations. Theadditivated
films of 300 um thickness were used for acceleratedageing under Desaga UVIS
apparatus at 366 nm for various lengthsof irradiation times, up to 35 days.
The films were investigaedby ir spectroscopy and by the determination of
electricalproperties, ie, dieletric constant E and loss factor E.
Colourdevelopment on ageing was monitored by CIE chromacity diagram.Thermal
ageing of thin plaques of LPD was also carried put. irspectrometry did not
reveal oxidized species in UV ageing andthe induction period of stabilized
LDPE troughout the irradiationtime may be presumed. Some of the
combinations of addedstabilizers produced interesting dependencies of the
dielectricloss levels. Ionic species formation and their disappearance
maybe postulated at relatively shorter irradiation times. Thepolarization
current was increased for longer aged samples.Yelowness index changes, in
spite of their fluctuation did notindicate any evidence for the formation
of coloured degradativeproducts in thermally aged LDPE stabilized by the
appliedcombination of stabilisers.
- Type of paper
: Summary in proceedings
Title: THERMAL AND UV-DEGRADATION OF MODIFIED IMPACT-RESISTANT
POLYSTYRENE
- Authors:
- Jelenčić, Jasenka (41450)
- Mlinac-Mišak, Marica (98560)
- Parać, Ivan (192843)
- Bravar, Mladen (5281)
Proceedings title: 33th IUPAC Congress
Language: engleski
Place: Budapest, Mađarska
Year: 1991
Pages: from 7070 to 0
Meeting: 33th IUPAC Congress
Held: from 08/17/91 to 08/22/91
Summary: A commercial type of blended impact-resistant polystyrene
(HIPS)was investigated. HIPS was modified
withmethacrylate-butadiene-styrene (MBS) in amounts of 5, 10, 15, 20and
25%. The samples were protected with antioxidant, Irganox245. Films, 300um
thick thermally treated at 100 C and separatelyu.v. irradiated at 360 nm
for 24, 72, 120 and 168 hours.Dumbbells and straigth test pieces were only
thermally treated on100 C for 7, 14, 21, 28 and 35 days. Colour change of
alldumbbells were measured on Elrepho in u.v./visibleregion.Measurements of
carbonyl and hydroxyl groups, as well aspolybutadiene unsaturation
absorbance of films were recorded oni. r. spectrophotometer.
- Type of paper
: Summary in proceedings
Title: RECENT DEVELOPMENT IN THE STUDY OF DEGRADATION AND
STABILIZATION ON SOME COMMERCIALLY IMPORTANT POLYMERS
- Authors:
- Bravar, Mladen (5281)
Proceedings title: 33th IUPAC Congress
Language: engleski
Place: Budapest, Mađarska
Year: 1991
Pages: from 765 to 0
Meeting: 33th IUPAC Congress
Held: from 08/17/91 to 08/22/91
Summary: Low density polyethylene submited to sucsessive injection
-moulding cycles to simulate reprocessing and/or recycling wascharacterized
in degradation terms including newly developedmethod for measuring
thermally stimulated depolarization currnet,TSDC. Impact-resistant
polystyrene, IPS, consisting of commercial polystyrene grafted with low
molecularcis-1,2-polybutadiene and containing added Irganox antioxidantswas
found to be fairly well protected to thermo-oxidativedegradation. Aromatic
polyurethane elastomers may undergodual-type photolytic yellowing pethways,
depending on the type ofUV-degradation and environmental condition.
- Type of paper
: Summary in proceedings
Title: DETERMINATION OF N-NITROSAMINES IN NATURAL RUBBER FILMS
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Bravar, Mladen (5281)
- Jelenčić, Jasenka (41450)
Proceedings title: Od uzorka do podataka i informacije
Language: hrvatski
Place: Opatija
Year: 1993
Pages: from 70 to 0
Meeting: Od uzorka do podataka i informacije
Held: from 10/20/93 to 10/23/93
Summary: During the vulcanization process of rubber compounds and in
thecourse of rubber processing organic chemicals are used asingredients in
small quantities. Some of them, however, mayproduce secondary amines, which
in turn may react with present NOcompounds that, in test on animals, are
recognized ascancerogenic substances even in the amounts of some tenths
ofppb,s. When trying to determine such small quantities ofN-nitrosamines, a
viable sample preparation method is necessary,as well as a reliable and
sensitive instrumental method fornitrosamine determination. The entire work
of the analyst willfully depend on the throughness in the sample
preparation. Inthis paper, for the preparation on the sample, the method
orrubber extraction in a sold phase, i.e. the sorbent extraction,has been
applied. The method has proved to be efficient, highlyselective and fast.
Additionally, the solvent usage is muchlesser than at standard separation
methods. After the extractconcentration, the qualitative and quantitative
analyticdetermination of the nitrosamine by GC/MS system was performed.
- Type of paper
: Summary in proceedings
Title: THERMAL DEGRADATION AND PHOTODEGRADATION ON POLYMERS AND
POLYMERIC MATERIALS
- Authors:
- Bravar, Mladen (5281)
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 7 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: CONTROLLED PLASTICS DEGRADATION
- Authors:
- Mlinac-Mišak, Marica (98560)
Proceedings title: Dani plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 8 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: PHOTOSTABILITY OF POLYURETHANE ELASTOMERS BASED ON
DIFFERENT MOLECULAR WEIGHT OF POLYOL
- Authors:
- Govorčin, Emi (127332)
- Rek, Vesna (40741)
- Sendijarević, Aiša
- Sendijarević, Vahid
- C. Frisch, Kurt
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 10 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: THE EFECT OF VARIOUS TYPES OF DIISOCYANATES ON
POLYURETHANE ELASTOMERS PHOTOSTABILITY
- Authors:
- Rek, Vesna (40741)
- Govorčin, Emi (127332)
- Sendijarević, Aiša
- Sendijarević, Vahid
- C. Frisch, Kurt
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 11 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: ULTRAVIOLET DEGRADATION OF NATURAL RUBBER VULCANIZED WITH
DIFFERENT TYPES OF ACCELERATORS
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 12 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: MODELLING OF PHYSICAL AGEING IN POLY/VYNIL ACETAT/
- Authors:
- Agić, Ante (137300)
- Bravar, Mladen (5281)
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 27 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: ELECTRICAL PROPERTIES OF LOW DENSITY POLYETHYLENE AND
(ETHYLENE-co-VYNILACETATE) COPOLIMERS
- Authors:
- Jelčić, Želimir (82275)
- Badanjak, Vesna
- Mlinac-Mišak, Marica (98560)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 30 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: RUBBER IN SURFACE PROTECTION
- Authors:
- Jelenčić, Jasenka (41450)
Proceedings title: 11. Dani Društva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 48 to 0
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 06/15/93 to 06/18/93
- Type of paper
: Summary in proceedings
Title: INFLUENCE OF SOME SOLVENTS ON THE SWELLING PROCESSES AND
ON THE MECHANICAL PROPERTIES OF COPOLYMER ACRYLATE SYSTEM
- Authors:
- Leskovac, Mirela (175223)
- Kovačević, Vera (74041)
- Bravar, Mladen (5281)
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 8 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: The coating system based on the copolymer butyl
acrylate/methylmethacrylate, BA/MMA was investigated on various use
properties.The added crosslinking agent was N-methylacrylamide, NMA.
Thesystem was exposed to the influence of selected solvent in orderto
determine their controling role in the course of the systemdepending by the
presence of the solvent, along with thedevelopment of equilibrium swelling
were monitored. Themechanical properties of the system were compared with
itsinitial structural parameters. These properties were found toreflect the
concurrent course of the degradation and crosslinking reactions. Some
conclusions may be drawn concering thedegradative processes exerted by
selected solvents and therepercussions on designing the behaviour of the
system in textileindustry processing conditions were discussed.
- Type of paper
: Summary in proceedings
Title: INFLUENCE OF THE INORGANIC COMPONENTS ON THE PROPERTIES OF
THE POLY(VINYLACETATE) COMPOSITIONS
- Authors:
- Lučić, Sanja
- Kovačević, Vera (74041)
- Bešić, Zdravka
- Hace, Drago (15006)
- Šmit, Ivan
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 8 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: The influence of some inorganic fillers in the
adhesivecomposition based on poly(vinil acetate) was investigated.Chemical,
physical and morphological characteristics of somesuitable fillers were
evaluated. The influence of the fillers onphysical, rheological and
chemical properties of adhesives in theform of polymeric films as well in
the prepared wooden joint wasdetermined. There were some conclusions
formulated deriving fromfindings which disclose the relationship between
the performancesof the adhesive joint and the chemical and
morphologicalcharacteristics of fillers in the adhesive composition.
- Type of paper
: Summary in proceedings
Title: INVESTIGATION OF MECHANICAL PROPERTIES OF VARIOUS
POLYACRYLATE SYSTEMS
- Authors:
- Cerovečki, Željko (17973)
- Stanojević, Duško (157596)
- Leskovac, Mirela (175223)
Proceedings title: 33rd IUPAC Congress
Language: engleski
Place: Budapest, Mađarska
Year: 1991
Pages: from 7112 to 0
Meeting: 33th IUPAC Congress
Held: from 08/17/91 to 08/22/91
Summary: Mechanical properties of complex polyacryle systems,
togetherwith other properties, represent a basis for optimisation ofmonomer
- additives ratio parameters obtained by mechanicalinvestigations enable
quantitative insight into influence ofmonomers and additives on mechanical
behaviour of materials andpossible improvement of physical properties.
- Type of paper
: Summary in proceedings
Title: MODIFICATION OF POLYACRYLATE COPOLYMERS AND THEIR
CHEMICAL STABILITY
- Authors:
- Stanojević, Duško (157596)
- Leskovac, Mirela (175223)
- Kovačević, Vera (74041)
Proceedings title: 33rd IUPAC Congress
Language: engleski
Place: Budapest, Mađarska
Year: 1991
Pages: from 7117 to 0
Meeting: 33th IUPAC Congress
Held: from 08/17/91 to 08/22/91
Summary: The investigations about influence of various monomers
incopolymer-acrylate system on the optimal properties were made.The
structural, morphological and mechanical properties weredefined depending
on obtained added additives and compositions.The samples in form of thin
films were subjected to the influenceof selected medias organic solvents
and/or water to researchtheir chemical stability.
The conclusions about dependence on composition and influence ofmedia based
on changes in chemical and mechanical properties weredrawn.
- Type of paper
: Summary in proceedings
Title: MECHANICAL PROPERTIES DEFINING OF POLYMER MATERIALS
- Authors:
- Leskovac, Mirela (175223)
- Kovačević, Vera (74041)
- Bravar, Mladen (5281)
- Stanojević, Duško (157596)
- Agić, Ante (137300)
Proceedings title: Od uzoraka do podataka i informacije
Language: hrvatski
Place: Opatija
Year: 1993
Pages: from 94 to 0
Meeting: Od uzorka do podataka i informacije
Held: from 10/20/93 to 10/23/93
Summary: The define of the requirements to be put on materials
andproducts ought to assure the quality control in production andevaluate
their application suitability. Mechanical properties ofa wide range of
polymeric materials based on polyacrylatesystems, along with other
characteristics, should be viewed asthe outer display picture of the inner
structure and therelationship of constituents, enabling the supervision
andprediction of their behaviour in defined application conditions.
The mode of approach in mechanical testing is not only highlyinfluence by
an investigation assignement, but also by commentsthat need to be
specified and that should be implemented in theprocessing program,
product, and/or application aim. Variousdirective-giving boards limit, in
their own manner, the testingconditions. We therefore give here the
comparison of theseconstraints, in order to offer conditions for the
efficacioustesting procedure.
A steady rise of demands put on materials and productperformances, along
with developments in informatics, hasresulted in computer controled systems
in the domain ofinstruments and apparatus for mechanical property testing.
Thepossibility to command and combine the input and outputparameters of the
applied programs, renders feasible themeasurement that comply with the
requests of boards and enablethe testing procedures that are adjusted to
specific needs of anyparticular investiagtion assignement.
A numeric/graphic method of the measurement process is presented,comprising
the statistical scheme by arranging the softwareparameters according to the
board requists. The conclusions aredrawn that conform to the defined input
information concerningthe materials composition effect and application
conditions.
- Type of paper
: Summary in proceedings
Title: LEATHER AS COMPOSITE
- Authors:
- Bajza, Željko (140705)
- Bravar, Mladen (5281)
- Kovačević, Vera (74041)
- Agić, Ante (137300)
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 7 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: According to its structure the animal skin as a natural
polymeris a multicomponential continuum with a distinct porosity.
Theleather as a porous membrane is analyzed in this article. Themechanical
behaviour is analyzed in terms of the thermodynamicsof materials. The
influence of humidity and vapour, of the fatcontent, as well as of the
finishing, on the quality of leatherare showed in this article. The
degradation with its side effectsis analyzed from the point of the
generalized diffusion. Usingthe simplified stratified model of materials
the whole complexityof mechanical examinations have been pointed to. The
articlepresents an analytical evaluation of the standard examinations
sofar. A from of a multicomponential material is suggested as
anillustration of the complexity of the morphological structure.The
material constant is discussed (definition anddetermination), e.g.
elasticity module, Poisson distribution,porosity, coefficient of thermo
diffusion, coefficient of volumedilatation, chemical potential. The
chemical potential and thereleased energy are mutually consistent. Beside
the mechanicalload the dominant force is the gradient of the
chemicalpotential. A comparison between the models of the structure
ofcollagen is carried out, such as the spatial presentation of
thearrangement of microfibrils in the stereocoordinate system, thespecial
arragement of sequences, the model of the formation ofcovalent bridges
between the chain and the formation of thecrystal netword of collagen. The
notion of strain and deformationis expressed in terms of the referential
volume.
- Type of paper
: Summary in proceedings
Title: STRUCTURAL CHANGES OF LEATHER IN PROCESS OF MANUFACTURING
MEASURED BY FOURIER-TRANSFORM INFRARED SPECTROSCOPY
- Authors:
- Bajza, Željko (140705)
- Posarić, J.
Proceedings title: European Conference on Analytical Chemistry
Language: engleski
Place: Edinburgh, Škotska
Year: 1993
Pages: from 7 to 0
Meeting: European Conference on Analytical Chemistry
Held: from 09/05/93 to 09/11/93
Summary: During the process of tanning and manufacturing, a raw
hidechanges its properties and chemical structure. Changes ofchemical
structure, related to removing some components of livetissues, like
globular proteins, fats or serum and adding orbonding of auxilliaries like
tannages, fat-liquors, limings,finishers, etc., could be analysed using
different analyticaltechniques and methods. One of the most powerful
techniques isthe structural analysis of complex materials,
infraredspectroscopy (IR), has been used in leather research for manyyears.
Developments made in the field of measurement of reflectedlight and the
introduction of fast Fourier transform (FT)techniques have established new
methods and their applicationshave been described recently. In this work
the structuralbehaviour of leather during the manufacturing
process,step-by-step, was of special interest. Samples prepared undernormal
conditions of manufacturing process were analysed usingmeasurements of
attenuated total reflected (ATR) light on Fouriertransform infrared (FTIR)
spectrophotometer. The FTIR spectra ofATR light from the surface show a
very complex pattern of signalrelated to the chemical structure of
additives and of leatheritself. Computed differential spectral analysis was
used to solvestructural problems caused by the complex structure of
leather,snatural matrix. A very large area of use of bouth techniques
wasfound in the fields of analysis and Q.C. in tanning processes.
- Type of paper
: Summary in proceedings
Title: INFLUENCE OF DIISOCYANATE COMPONENTE ON THE PHOTOSTABILITY
OF POLYURETHANE
- Authors:
- Rek, Vesna (40741)
- Govorčin, Emi (127332)
Proceedings title: 34th International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 57 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: The influence of UV irradiation on the stability of
polyurethaneelastomer, PUR, on the base of aromatic
4,4-diphenylmethanediisocyanate and aliphatic 4,4-dicyclohexylmethane
diisocyanatewere investigated. The polyol component was
poly/caprolactone/glycol and chain extender was 1,4-butanediol. Synthesis
reactionwas performed by the procedure of prepolymer and at molecularratio
NCO/OH 2/1 and 4/1. The mixture was pressmoled in a Carverpress at 100 C.
The stability against UV irradiation werefollowed throught the changes of
mechanical and dynamichemicalproperties as well as trought the changes in
physical transitionsand morphological structure of PUR. The results showed
that thestability of the investigated polyurethanes depend on
thediisocyanate component and their content in synthesis of PUR.
Theprocesses of photooxidative degradation are more expressed in PURon the
base of aliphatic diisocyanate. The higher NCO/OH ratio inPUR on the base
of aliphatic diisocyanate also lead to greaterdegradative processes. The
extents of photooxydative degradationof the examined PUR elastomers
correlate well with the extents ofthe changes in mechanical properties,
phase transitions andmorphological structure. The aromatic polyurethane has
greaterstability from the view of the mechanical properties but
thestability is less expressed againts the changes of the colour.
- Type of paper
: Summary in proceedings
Title: THE EFFECTS OF DIFFERENT MOLECULAR WEIGHT OF SOFT SEGMENT
IN POLYURETHANE ON THEIR PHOTOOXIDATIVE STABILITY
- Authors:
- Govorčin, Emi (127332)
- Rek, Vesna (40741)
Proceedings title: 34th International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 58 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: The effects of molecular weight of soft segment in
segmentedpolyurethane, PUR, elastomers on their photooxidative
stabilitywere investigated. The irradiation was performed using the
UVlamp. PUR elastomers were on the base of polyether soft segmentswith
different molecular weight and different NCO/OH ratio. Twoseries of PUR
elastomers were synthetised.The first is based onhard segment of
4,4-diphenylmethane diisocyanate, MDI, chainextended with 1,4-butanediol,
BD, and poly/oxytetramethylene/glycol M.W.=1000, PTMEG. The second series
is also based on hardsegments made from MDI and BD but with
poly/oxytetramethylene/glycol M.W.=2000, PTMEG. For both series the NCO/OH
ratio was2/1and 4/1. The changes in structure and properties
afterirradiation were followed using a thermal analysis, dynamicmechanical
testing and stress-strain behaviour. It was found thatthe molecular weight
of soft segments as well as the NCO/OH ratiohave the influence on the UV
staility of the exmined PURelastomers. The correlation between the
compositions of the bothsinvestigated series of PUR elastomers and the
intensities of thechanges of mechanical properties as well as phase
transitionsafter iradiation were established.
- Type of paper
: Summary in proceedings
Title: DEGRADATION OF POLYURETHANE
- Authors:
- Rek, Vesna (40741)
Proceedings title: 11 Dani DruŠtva plastičara i gumaraca
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 5 to 6
Meeting: 11. Dani Društva plastičara i gumaraca
Held: from 07/15/93 to 07/18/93
- Type of paper
: Summary in proceedings
Title: POLYURETHANE FLEXIBLE FOAMS ON THE BASE OF POLYMER POLYOLS
- Authors:
- Sadadinović, Jasminka
- Rek, Vesna (40741)
Proceedings title: 12. Leobener Kunststoff Kolloquium
Language: engleski
Place: Leoben, Austrija
Year: 1993
Pages: from 0 to 0
Meeting: XII Leobener Kunststoff - Kolloquium
Held: from 11/01/93 to 11/03/93
- Type of paper
: Summary in proceedings
Title: CHARACTERIZATION OF CHEMICAL AND MORPHOLOGICAL STRUCTURE
OF SEGMENTED POLYURETHANE
- Authors:
- Rek, Vesna (40741)
Proceedings title: 12. Leobner Kunststoff Kolloquium
Language: engleski
Place: Leoben, Austrija
Year: 1993
Pages: from 0 to 0
Meeting: 12. Leobner Kunststoff Kolloquium
Held: from 11/01/93 to 11/13/93
- Type of paper
: Summary in proceedings
Title: POLYURETHANE ELASTOMERS AND THEIR MECHANICAL PROPERTIES
UNDER DEGRADATION INFLUENCE
- Authors:
- Kovačević, Vera (74041)
- Hace, Drago (15006)
- Sučeska, Muhamed (5281)
Proceedings title: 33th IUPAC Congress
Language: engleski
Place: Budapest, Mađarska
Year: 1991
Pages: from 259 to 0
Meeting: 33th IUPAC Congress
Held: from 08/17/91 to 08/22/92
Summary: The thermal structure of polyurethane elastomers as a
maincomponents in adhesive composition could flay important role
inmechanical properties. The stess-strain curves were correlatedwith
specific morphology characteristics. The results fromdynamic mechanical
measurements are provided and discussed inorder to develop the fundamental
relation between the propertiesand structure in whole, especially in
degradative conditions.
Keywords: polyurethane adhesive composition, mechanical properties, dynamic mechanical analysis, structure and properties of polyurethane, degradation.
- Type of paper
: Summary in proceedings
Title: STUDY OF CHEMICAL AND THERMAL DEGRADATION OF IMPACT
RESISTANT POLYSTYRENE AFTER NITRIC ACID ATTACK
- Authors:
- Hace, Drago (15006)
- Kovačević, Vera (74041)
- Pajc, Davorka
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 62 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: Some grafted copolymer system based on butadiene/styrene,
HIPS,were processed by extrusion, pressing and injection mouldingtechniques
into test plaques which were afterwards submitted tothe action of agressive
medium, concentrated nitric acid atseveral temperatures for various time
periods. The reactions onthe surface of samples were studied by IR
spectroscopy as well asby Tg determinations and weight losses which were
correlated withtoughness changes, mechanical properties diminishing
andmicroscopy observations. The structure of molecular packing wascredited
for sorption phenomena and for the diffusion and theoxidative degradation
in the heterogeneous composition of polymermatrix of grafted
butadiene/styrene copolymer as well as in thegel phase of multiphase of the
polymeric system. Some conclusionswere given concerning the limits of the
HIPS material resistanceto the process of hydrolyse, nitration and
oxidative degradationat various test temperatures in reference to the
preparationmethods of the test plaques.
Keywords: grafted copolymer systems HIPS, agressive medium - concentrated nitric acid, toughness, thermal properties, hydrolysis, nitration, oxidative degradation.
- Type of paper
: Summary in proceedings
Title: INFLUENCE OF THE INORGANIC COMPONENTS ON THE PROPERTIES
THE POLY(VINYL ACETATE) COMPOSITIONS
- Authors:
- Lučić, Sanja (186655)
- Kovačević, Vera (74041)
- Bešić, Zdravka
- Hace, Drago (15006)
- Šmit, Ivan
Proceedings title: 34th IUPAC International Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 3 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: The influence of some inorganic fillers in the
adhesivecomposition based on poly(vinyl acetate) was investigated.Chemical,
physical and morphological characteristics of somesuitable fillers were
evaluated. The influence of the fillers onphysical, reological and chemical
properties of adhesives in theform of polymeric films as well in the
prepared wooden joint wasdetermined. There were some conclusions formulated
deriving fromfindings which disclose the relationship between the
performancesof the adhesive joint and the chemical and
morphologicalcharacteristics of fillers in the adhesive composition.
Keywords: poly(vinyl acetate) adhesive composition, inorganic fillers, film properties of adhesive, wooden adhesive joint.
- Type of paper
: Summary in proceedings
Title: PREPARATION AND CHARACTERIZATION OF IRON (II) POLYMERIC
CHELATES WITH DL-METHIONINE
- Authors:
- Hace, Drago (15006)
- Đanić, E.
- Šmit, Ivan
- Đanić, Husein
Proceedings title: 34th IUPAC Internatioal Symposium on Macromolecules
Language: engleski
Place: Prag, Čehoslovačka
Year: 1992
Pages: from 48 to 0
Meeting: 34th IUPAC International Symposium on Macromolecules
Held: from 07/13/92 to 07/18/92
Summary: Complexes of biologically essential amino acids iron (II)
werethe subject of many investigations. They take important role inlife
activity of human organism. The chelates of iron andmethionine examined
before did not show tendency of forming Fe-Sbond. Only the -NH group and
one or both oxygen atoms fromcarboxylate group coodinated with iron. The Fe
(III) methioninechelate had a monomeric structure (1), and Fe (II) chelate
ofsame kind formed a weakly associated polymeric structure (2).Synthesis
and properties of iron (II) Fe-S bonding polymericchelate with
DL-methionine were investigated. The complexes wereprepared with FeCl*7HO
and FeSO*4HO. Iron to sulfur bond wasproved by IR spectrometry. Carboxylate
bridges were alsodetermined in polymeric complex. For structural
identification ofpolymer properties the following methods were used: IR,
UV/VISspectrometry, WAXD, elementary and TG analysis. The yield ofreaction
and stability properties will be also discussed. On thebasis of
investigation information the structure of polymericcomplex was suggested.
Keywords: Iron(II) polymeric chelates with DL-methionine, chemical bonds in chelates, structural identification WAXD, elementary and Tg analysis, structure of polymeric complex.
- Type of paper
: Summary in proceedings
Title: PROPERTIES OF ADHESIVES AND ADHESIVE BONDS IN APPLICATION
CONDITIONS
- Authors:
- Kovačević, Vera (74041)
- Lučić, Sanja
- Hace, Drago (15006)
- Cerovečki, Željko (17973)
Proceedings title: Od uzoraka do podataka i informacija
Language: hrvatski
Place: Opatija
Year: 1993
Pages: from 124 to 0
Meeting: Od uzorka do podataka i informacije
Held: from 10/20/93 to 10/23/93
Summary: Adhesive problems and measuring methods for investigations
ofadhesive materials are very important for production, qualitycontrol and
in specific case adhesive joint assurance. Concerningthe variations,
several standards and methods of specificanalysis were compared. In the
paper the results of polyurethaneand polychloroprene adhesive were
considered along with themethods of investigations of specific properties
viscosity, drycontent and shear and peel strengths. The conclusions
aboutadhesive products conserned the specific characteristcs ofadhesives
and adhesive joints, also in degradative conditions.
Keywords: adhesives, adhesive joints, standards, methods to solve specific problems, degradative conditions.
- Type of paper
: Summary in proceedings
Title: MECHANISM OF COPOLYMERIZATION OF ALPHA-METHYLSTYRENE AND
MALEIMIDE
- Authors:
- Fleš, Dragan (68924)
- Vuković, Radivoje
- Kurešević, Vjera
- Fleš, Dragan
Proceedings title: XII Sastanak kemičara Hrvatske
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 225 to 0
Meeting: XII Sastanak kemičara Hrvatske
Held: from 02/11/91 to 02/13/91
- Type of paper
: Summary in proceedings
Title: PREPARATION OF BLEND OF ALTERNATIG COPOLYMERS AND
HOMOPOLYMERS OF CORRESPONDING ELECTRON ACCEPTORS BY CHEMICAL METHOD
- Authors:
- Vuković, Radivoje
- Ranogajec, Franjo
- Fleš, Dragan (68924)
- Fleš, Dragan
Proceedings title: XII Sastanak kemičara Hrvatske
Language: hrvatski
Place: Zagreb
Year: 1991
Pages: from 155 to 0
Held: from 02/11/91 to 02/13/91
- Type of paper
: Summary in proceedings
Title: STRUCTURE OF POLY(4-N-(BENZO-15-CROWN-5)MALEIMIDE) AND
COPOLYMER POLY(4-N-(BENZO-CROWN-5)MALEIMIDE-ALT-ALPHA-METHYLSTYRENE)
DETERMINED BY WAXD METHOD
- Authors:
- Šmit, Ivan
- Fleš, Dragan (68924)
Proceedings title: XIII Skup hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 64 to 0
Held: from 02/08/93 to 02/10/93
- Type of paper
: Summary in proceedings
Title: COMPLEXES OF SODIUM AND POTASSIUM IONS WITH
4-N-(BENZO-15-CROWN-5)MALEIMIDE) AND
POLY(4-N-(BENZO-15-CROWN-5)MALEIMIDE-ALT-ALPHA-METHYLSTYRENE)
- Authors:
- Fleš, Dragan (68924)
- Hace, Drago (15006)
- Ranogajec, Franjo
- Vuković, Radivoje
Proceedings title: XIII Skup hrvatskih kemičara
Language: hrvatski
Place: Zagreb
Year: 1993
Pages: from 104 to 0
Held: from 02/08/93 to 02/10/93
- Type of paper
: Summary in proceedings
Title: THE ROLE OF RUBBER PRODUCTS DURABILITY IN MARINE
ENVIRONMENT AGEING CONDITIONS
- Authors:
- Bravar, Mladen (5281)
- Jelenčić, Jasenka (41450)
- Hrnjak-Murgić, Zlata (120683)
- Travaš-Sejdić, Jadranka (186622)
Proceedings title: epf 94
Language: engleski
Place: bASEL, SWITZERLAND
Year: 1994
ISBN/ISSN: 0
Pages: from 2.10 to 0
Meeting: 5th European Polymer Federation Symposium on Polymeric Materials
Held: from 10/09/94 to 10/12/94
Summary: The overview presents issues along with some dilemmas and
difficulties arising in the course of the selection of the reliable
elastomeric materials for the production of structural parts and products
in shipbuilding. The existing lack of materials and products
standardization concering the durability in service in marine environment
may be partly composed by considering the novel findings obtained in
outdoor terrestrial environmental ageing and in accelerated laboratory
tests. The need for establishing the real marine environment polymer ageing
experiments and simulating them appears as a necessary assignment for
materials scientists in naval arhitecture and shipbuilding.
- Type of paper
: Summary in proceedings
Title: PHOTOSTABILITY OF POLYURETHANE ELASTOMERS BASED ON VARIOUS
TYPES OF DIISOCYANATES
- Authors:
- Rek, Vesna (40741)
- Govorčin, Emi (127332)
- Editors
- 0, 0
Proceedings title: EPF 94
Language: engleski
Place: BASEL, SWITZERLAND
Year: 1994
ISBN/ISSN: 0
Pages: from 2.38 to 0
Meeting: 5th European Polymer Federation Symposium on Polymeric Materials
Held: from 10/09/94 to 10/12/94
Summary: The effect of UV radiation on the mechanical and
thermomechanical properties of polyurethane (PUR) elastomers and their
morphology was studied. The PUR elastomers were based on an aromatic
isocyanate (4,4'-diphenylmethane diisocyanate) and a cycloaliphatic
isocyanate (4,4'-dicyclohexylmethane diisocyanate). Poly(caprolachone)
glycol of 1250 molecular weight was the polyol used and 1,4-butanediol was
the chain extender. The elastomers were prepared in a two step procedure.
First, prpolymers were prepared from poly(caprolactone) glycol by reacting
with the corresponding isocyanate at NCO:OH ratios of 2:1 and 4:1. The
prepolymers were then chain extended with 1,4-butanediol and the mixtures
were press molded in a platen press at 100 C.The results showed that the
stability of the investigated PUR elastomers depended on the chemical
strucure of the diisocyanate and the hard/soft segment ratio. The processes
of photooxidative degradation are more prevalent in PUR elastomers based on
the cycloaliphtic isocyanate than those based on the aromatic isocyanate,
in the case of PUR elastomers based on the cycloaliphatic isocyanate it was
found that the photodegradative process were enhanced with increasing hard
segment concentration. Although PUR elastomers based on the aromatic
isocyanate undergo color changes they exhibited better relation of
mechanical properties compard to those based on the aliphatic isocyanate.
- Type of paper
: Summary in proceedings
Title: PHOTODEGRADATION OF POLYURETHANES
- Authors:
- Rek, Vesna (40741)
Proceedings title: EFP 94
Language: engleski
Place: BASEL, SWITZERLAND
Year: 1994
ISBN/ISSN: 0
Pages: from 2.38 to 0
Meeting: 5th European Polymer Federation Symposium on Polymeric Materials
Held: from 10/09/94 to 10/12/94
Summary: This paper ia s review of the investigations of
photooxidative degradation of polyurethane, PUR. The mechanism of
photooxidative degradation and secondary crosslinking reactions in PUR are
presented. The course and the intensity of the changes in molecular,
supermoleculr and morphological structures of PUR due to photooxidative
degradatin are reviewed. These structural changes were followed by
comparative spectroscopic measurements (IR, NMR, UV), as well as by DSC
analysis, DMA, X-ray measurements, electron microscopy and GPC measurements
of PUR samples before and after various times of photooxidtive degradation.
The influence of the nature of the polyols and the isocyanate components
used in the synthesis of PUR on the photodegradative process and changes in
PUR structures mentioned above as well as on the rate of yellowing of PUR
samples are discussed. The correlation between intensities of structural
changes of PUR and its mechanical properties are presented. The influence
of the physical state of PUR and the thickness of the PUR samples on the
photooxidative stability of PUR are also described.
- Type of paper
: Summary in proceedings
Title: THE INFLUENCE OF ACCELERATORS OF SULPHUR VULCANIZATION ON
THE STRUCTURE OF CROSSLINKING
- Authors:
- Vrban, Ljiljana
- Travaš-Sejdić, Jadranka (186622)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
- 0, 0
Proceedings title: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makr
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 0
Pages: from s-426 to 0
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: THE EFFECT FO MOLECULAR WEIGHT OF POLYOLS ON
PHOTOSTABILITY IN POLYURETHAN ELASTOMERS
- Authors:
- Govorčin, Emi (127332)
- Rek, Vesna (40741)
- Sendijarević, Aiša
- Sendijarević, Vahid
- C. Frisch, Kurt
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 0
Pages: from S-449 to 0
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: ANNAEALING PROCESS IN SEGMENTED POLYURETHANE
- Authors:
- Rek, Vesna (40741)
- Govorčin, Emi (127332)
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 0
Pages: from S-456 to 0
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: STUDY OF THERMOCHEMICAL DEGRADATION SYSTEM OF
COPOLYMER/BUDADIENE-g-STYRENE/
- Authors:
- Pajc, Davorka
- Hace, Drago (15006)
- Kovačević, Vera (74041)
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 0
Pages: from S.447 to 0
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title:
- Type of paper
: Summary in proceedings
Title: EFFECT OF MOLAR VOLUME OF SOLVENT AND VULCANIZATE
STRUCTURE ON INTERACIONS IN THE SYSTEM SOLVENT-CROSSLINKED POLYMER
- Authors:
- Hrnjak-Murgić, Zlata (120683)
- Jelenčić, Jasenka (41450)
- Bravar, Mladen (5281)
- Marović, Marijana
- 0, 0
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from S-450 to 0
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: X-RAY INVESTIGATIONS OF BICOMPONENT INJECTION MOULDED
POLYPROPYLENE
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Zipper, P.
Proceedings title: Sinopsisi
Language: engleski
Place: Zagreb
Year: 1995
Pages: from S-437
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
Summary: Rectangular plates obtained by bicomponent injection
moulding of commercial polypropylenes were investigated by applying wide
angle x-ray methods. The mouldings were prepared on the way that skin and
core of the plates are the same materials or materials differing in molar
mass distribution. The influence of different skin and core materials on
the distribution of crystallite modifications and preferred orientation in
the mouldings are derived from intensities of scattering reflections. Since
the structure varies with increasing distance from the gate profiles of
several parameters characterizing the orientation and concentration of the
crystallite modifications, as well as apparent crystallite sizes l(hki),
are evaluated and presented in dependance on the distance from the gate.
The degree of alignement of the crystallographic direction c with the
reference direction z (flow direction) are expressed wqith the values of
the mean square cosine cos2O. The results show that viscosity, e.g. molar
mass distribution, has a profound effect on orientation of
alfa-crystallites and amount and distribution of beta-modification. In
general, the4 high viscosity materials have higher oriented
alfa-crystallites in surface layers, the bigger crystallite size L(hkl),
and higher amount of beta-modification which increases with increasing
distances from the gate.
- Type of paper
: Summary in proceedings
Title: ESTERIFICATION OF SORBITOL AND LAURIC ACID WITH CATALYST
p-TSA
- Authors:
- Giacometti, Jasminka
- Wolf, Nikola (54274)
- Gomzi, Zoran
- Milin, Čedomila
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
ISBN/ISSN: 0
Pages: from B-121 to 0
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: THE INFLUENCE OF CaCO3 FILLER ON THE PROPERTIES OF
POLY(VINYL ACETATE) BASED POLYMERS
- Authors:
- Lučić, Sanja
- Kovačević, Vera (74041)
Proceedings title: Sinopsisi
Language: hrvatski
Place: Zagreb
Year: 1995
Pages: from S-461 to 0
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
- Type of paper
: Summary in proceedings
Title: STRICTURAL MECHANICS OF BIOLOGICAL TISSUE
- Authors:
- Agić, Ante (137300)
Proceedings title: 3th Inter.Congress on Industrial and Applied Mathematics
Language: engleski
Place: Hamburg, Njemačka
Year: 1995
Pages: from 217
Meeting: 3th Inter.Congress on Industrial and Applied Mathematics
Held: from 07/05/95 to 07/09/95
Summary: The mechanical Behaviour of the tissue as collagen fiber
structure embedded in matrix (ground substance) has modeled in order to
better understanding some observed fascinate phenomena. The stress-strain
constitutive relations for collagen fibers have based on a
three-dimensional Lanir stochastic model. The randomness of the
microstructure has described by the fiber's volume rations, their
orientation and undulation distribution functions. Transition from
microscopic to the macroscopic overall response has formulated by the use
of probabilistic micromechanics and homogenization theory. A Voronoi Cell
Finite Element has used to solve numerically constituent balance equations.
Keywords: Biological Tissue, Lanir stochastic model, Voronoi cell finite element, Homogenization, Micromechanics
- Type of paper
: Summary in proceedings
Title: X-RAY INVESTIGATIONS OF BICOMPONENT INJECTION MOULDED
POLYPROPYLENE
- Authors:
- Travaš-Sejdić, Jadranka (186622)
- Zipper, P.
- Eigell, F.
Proceedings title: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makr
Language: engleski
Place: Zagreb
Year: 1995
Pages: from S-437
Meeting: XIV. Skup hrvatskih kemičara i IV. hrvatski simpozij o kemiji i tehnologiji makromolekula
Held: from 02/06/95 to 02/08/95
Summary: Rectangular plates obtained by bicomponent injection
moulding of commercial polypropylenes were investigated by applying wide
angle x-ray methods. The mouldings were prepared on the way that skin and
core of the plates are the same materials or materials differing in molar
mass distribution. The influence off different skin and core materials on
the distribution of crystallite modifications and preferred orientation in
the mouldings are derived from intensities of scattering reflections. Since
the structure varies with increasing distance from the gate profiles of
several parameters characterizing the orientation and concentration of the
crystallite modificatyions, as well as apparent crystallite sizes L(hkl),
are evaluated and presented in dependance on the distance from the gate.
The degree of alignement of the crystallographic direction c with the
values of the mean-square socine. The results show that
viscosity, t.g. molar mass distribution, has a profound effect on
modification. In general, the high viscosity materials have higher oriented
alfa-crystallites in surface layers, the bigger crystallites in surface
layers, the bigger crystallite siye L(hkl), and higher amount of
beta-modification which increases with intereasing distances from the gate.
- Type of paper
: Ph.D.
Title:
Faculty: Fakultet strojarstva i brodogradnje Zagreb
Author: AGIĆ ANTE
Date of defense: 03/31/94
Language: hrvatski
Number of pages: 140
Summary: The analzsis of stress-strain behaviors of viscoelastic
bodies is studied in this work. By applying the method of internal
variables in thermodynamics of continua, the general equations of nonlinear
viscoelastic behavior are developed. The formalisms of internal variables
made it possible to incorporate the effect of humidity, damage, ageing or
other phenomena into the constitutive equations. The isotropic viscoelastic
continuum is described by three thermodynamic functions and the
superposition factor. The constitutive equations which are developed
represent the basic elements of numerical model of thermoviscoelastic
behavior. Interpolation of the displacement field and geometry of the body
is performed by the finite element method. Nonlinear equilibrium equations
are solved by incremental procedure. For each time step the equilibrium
value of stress and strain and the participating increment of material time
was iteratively determined. For the plane stress and plane strain, as well
as for axially symmetric three dimensional bodies, computer program was
developed. Program was tested by the illustrative example of the analysis
of stress-strain in viscoelastic cylinder caused by transient temperature
field.
Keywords: nonlinear viscoelasticity, internal coordinates, finite element, methods, thermodynamics of continuua
- Type of paper
: Ph.D.
Title:
- Type of paper
: Ph.D.
Title:
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Author: BAJZA ŽELJKO
Date of defense: 07/15/94
Language: hrvatski
Number of pages: 140
- Type of paper
: M.A.
Title: CHARACTERIZATION OF THE NATURAL RUBBER VULCANIZATES
OBTAINED WITH DIFFERENT ACCELERATORS, AND CONSIDERATION OF THE PROBLEMS OF
N-NITROSAMINES
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Author: TRAVAŠ-SEJDIĆ JADRANKA
Date of defense: 04/14/94
Language: hrvatski
Number of pages: 114
Summary: The investigation of suitability of a few sulphur
vulcanization's accelerators as a substitution for zinc
diethyldithiocarbamate were examined. Zinc diethyldithiocarbamate has been
recognized as a chemical responsible in building carcinogenic
N-nitrosamines during reactions of vulcanization. The presence of the
carcinogenic N-nitrosamines in the natural rubber latex films vulcanized
with accelerator zinc diethyldithiocarbamate and combination of
accelerators zinc mercaptobenzothiazole/diphenulguanidine was investigated.
It was investigated whether the films vulcanized with accelerators zinc
mercaptobenzothiazole, diphenylguanidine do satisfy expected
physico-mechanical, chemical, and other properties. Samples of natural
rubber latex films were prepared by sulphur vulcanizations with the
different concentrations of four stated accelerators. The volatile
n-nitrosamines and a substances wich turn into N-nitrosamines after
nitrosation were isolated from the samples by ectraction with "artificial
saliva". The qualitative and quantitative analyses of N-nitrosamines were
performed by gas chromatography/mass spectrometry system. In atention to
estimate the network structures of vulcanized films and crosslinking
efficiency of the accelerators the determinations of network chain
concentrations were carrying out by the method of equilibrium swelling of
the vulcanized films in benzene. To examine the mechanical properties of
vulcanized films and to correlate the effect of accelerators on the
mechanical properties the stress-strain measurements were performed. The
change of mechanical properties of the vulcanized films during degradation
processes of oxidative thermal, photooxidation, and ozone degradations were
followed. Chemical changes which occured in vulcanizated films during
photooxidation were recorded by IR spectroscopy. The results confirmed that
natural rubber latex films vulcanized with accelerator zinc
diethyldithiocarbamate show a certain levels of the volatile
N-nitrosamines, as well as the substances wich turn into N-nitrosamines
afternitrosation. In the films vulcanized with combination of accelerators
zinc mercaptobenzothiazole/diphenylguanidine the volatile N-nitrosamines
were not confirmed. The results of determinations of the network chain
concentrations and the stress-strain measurements, before and after rubber
degradation, allow the conclusion that the combination of accelerators zinc
mercaptobenzothiazole/diphenylguanidine may be viewed as a proper
substitute for the accelerator zinc diethyldithiocarbamate.
Keywords: degradation, crosslink concentration, N-nitrosamines, physico-mechanical properties, natural rubber, sulphur vulcanization's accelerator, rubber vulcanizate
- Type of paper
: M.A.
Title: ŽIVANJE UTJECAJA ANORGANSKE KOMPONENTE NA SVOJSTVA
POLIMERNIH KOMPOZICIJA NA BAZI POLI(VINIL-ACETATA)
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Author: LUČIĆ SANJA
Date of defense: 07/12/94
Language: hrvatski
Number of pages: 88
Summary: In the present work, the influences of inorganic component
on the properties of the poli(vinul-acetate) adhesive composition were
investigated. The aim of the work was to investigate the effect of filler
characteristics on the interactions in the interphase. Morphological and
granulometric characteristics such as particle shape, diameter, particle
size distribution and specific surface area have specific influence,
besides the importance of chemical surfaces, on the rheological and
mechanical properties of the PVAC composition. The results provided that
more spherical mediu,, fine calcite pareticles with low specific surface
area and borad particle size distribution, surface treated with stearic
acid contribute in the interphase to the lower stresses and viscosity of
the system. As the result of interactions with polymer matrix higher
strength and toughness of the composite film duet to lower amount of the
stress points but with retained elasticity was obtained.
Keywords: Poly(vinyl-acetate) composition, Calcite fillers, Stearic acid tretment, Filler characterisation, Rheological behaviour, Mechanical properties
- Type of paper
: M.A.
Title: STUDY OF THERMO-CHEMICAL DEGRADATION OF COPOLYMER
(BUTADIEN-g-STYRENE) SYSTEM
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Author: PAJC-LIPLIN DAVORKA
Date of defense: 12/28/94
Language: hrvatski
Number of pages: 128
Summary: Processes of thermo-chemical degradation and transformation
of high impact polystyrene (PS-HI) under influences of concentrated nitric
acid were investigated by various temperatures and time. Comparative, pure
polystyrene and butadiene were exposed under the same conditions and
ezplored as a components of complex copolymer/butadiene-g-styrene/system to
get insight into the processes of oxidation degradation and nitration of
PS-HI system. The mechanisms of simultaneous and/or preferable path of
reactions depending on the treatment conditions were proposed, based on
comparative measurements of IR, UV and 1HNMR spectroscopy and yellow index.
Thermal DSC, TGA and DMA analysis along with viscosity number and nitric
content were made also after fraction of copolymer samples. Mechanical and
morphological measurements before and after nitric acid exposure were done.
Various oxidative structures in styrene/butadiene copolymer chains were
proved such as introduction of nitro group in aromatic and aliphatic part
of copolymer system. At lower temperature the results showed that the
primary reactions of copolymer nitration existed, but simultaneous and
preferable oxidation caused also the molecule degradation at higher
temperature. Multiplet of microcrazing wered created and changed the
morphological structure what improved further media diffusion into the
copolymer system. Molecular inhomogenity of polystyrene samples, after the
same exposure to conc. nitric acid at higher temperatures and time, was
found after partial fractionation into oligomer fractions such as sol
fractions soluble in benzene and gel fractions insolube in benzene but
soluble in dimetilformamide. Soluble fractions were characterized with
formed oxidative groups and gel fractions with preferable nitro groups and
mostly lower viscosity number. The mechanical properties of investigated
(PS-HI) system was lowered as a consequence of ageing process and
degradation. The conclusions about processes were made based on partial
investigations of the system components.
Keywords: copolymer(styrene-g-butadiene), nitric acid, ageing, oxidative degradation, chemical degradation, fractionation, IR-spectra, UV-spectra, structural analysis, scanning electron microscopy, mechanical properties, thermogravimetric analysis differential scanning colorimetry, dynamic mechanical analysis
- Type of paper
: Mentorship
Title: THE STUDY OF SYNTHESES NAD PROPERTIES OF POLYMER POLYOLS
AND INFLUENCE OF POLYMER POLYOLS STRUCTURE ON THE PROPERTIES OF COULD
MOULDING POLYURETHANE FOAMS
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Date of defense: 11/02/92
Number of pages: 130
Author: Sadadinović dipl. ing. Jasminka
Degree level: Ph.D.
- Type of paper
: Mentorship
Title: THERMAL TREATMENT COAL FOR PITCHES AND PITCH COMPOSITES
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Date of defense: 11/19/92
Number of pages: 94
Author: Vuletić-Šagarjelo dipl. ing. Slavka
Degree level: M.A.
- Type of paper
: Mentorship
Title: CHARACTERIZATION OF THE NATURAL RUBBER VULCANIZATES
OBTAINED WITH DIFFERENT ACCELERATORS, AND CONSIDERATION OF THE PROBLEMS OF
N-NITROSAMINES
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: JELENČIĆ JASENKA
Date of defense: 04/14/94
Number of pages: 114
Author: Travaš-Sejdić pripravnik Jadranka
Degree level: M.A.
- Type of paper
: Mentorship
Title: INVESTIGATION OF INORGANIC COMPONENT INFLUENCE ON THE
PROPERTIES OF THE POLI(VINYL-ACETATE) COMPOSITION
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: KOVAČEVIĆ VERA
Date of defense: 07/12/94
Number of pages: 88
Author: Lučić dipl. ing. Sanja
Degree level: M.A.
- Type of paper
: Mentorship
Title: THE INFLUENCE OF MEDIA ON DEFORMATION OF POLYAMIDE 6
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: REK VESNA
Date of defense: 11/15/94
Number of pages: 114
Author: Španiček magistar Đurđica
Degree level: Ph.D.
- Type of paper
: Mentorship
Title: DEPENDENCE OF PROCESSES OF MECHANICAL DEFORMATION OF
LEATHER MATERIALS IN CONECTION WITH STRUCTURE
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Mentor: KOVAČEVIĆ VERA
Date of defense: 07/10/94
Number of pages: 140
Author: Bajza Željko
Degree level: Ph.D.
- Type of paper
: Mentorship
Title: STUDYK OF THERMO-CHEMICAL DEGRADATION OF COPOLYMER
(BUTADIEN-g-STYRENE)SYSTEM
Faculty: Fakultet kemijskog inženjerstva i tehnologije Zagreb
Date of defense: 12/28/94
Number of pages: 128
Author: Pajc dipl. ing. Davorka
Degree level: M.A.
- Type of paper
: Survey/Study
Title: QUALITY PRODUCTION ASSURANCE OF POLYURETHANE ADHESIVE
TERMOFIX
- Authors:
- Kovačević, Vera (74041)
Ordering party: Chromos, Tvornica sintetskih smola
Year: 1994
Number of pages: 12
Language: hrvatski
Summary: In this study the quality characteristics of new product
adhesive Termofix used in shere and allied industry were defined based on
literature references and quality assurance needs in ISO 9000 series. The
investigation methodology were also defined. The conclusions about product
quality which could serve the producer as market references as well as the
part in quality assurance szstem in enterprice were drown.
Keywords: product quality assurance, adhesive Termofixd based on PUR, new product
- Type of paper
: Invited lecture
Title: DEGRADATION OF POLIURETHANES, Dr.sc. Vesna Rek
Institution: Fakultet kemijskog inženjerstva i tehnologije
Year: 1995
- Type of paper
: Invited lecture
Title: DEGRADATION OF POLY(BUTADIENE-1,4-g-STYRENE)
Institution: Fakultet kemijskog inženjerstva i tehnologije
Year: 1995
- Type of paper
: Invited lecture
Title: INVESTIGATION OF COMPOSITE PROPERTIES OF
POLY(VINYL_ACETATE)
Institution: Fakultet kemijskog inženjerstva i tehnologije
Year: 1995
- Type of paper
: Invited lecture
Title: THE INFLUENCE OF ADHESION POLYMER-FILLERS ON THE FILMS OF
POLIVYNILACETATES ADHESIVE
Institution: Fakultet kemijskog inženjerstva i tehnologije
Year: 1995
- Type of paper
: Invited lecture
Title: RUBBER IN SURFACE PROTECTION
Institution: Fakultet kemijskog inženjerstva i tehnologije
Year: 1993
- Type of paper
: Invited lecture
Title:
