SVIBOR - Papers quoted in CC - project code: 2-15-028

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Papers quoted in Current Contents on project 2-15-028

Quoted papers: 25
Other papers: 115
Total: 140

Title: CHARACTERIZATION OF THE NATURAL RUBBER VULCANIZATES OBTAINED BY DIFFERENT ACCELERATORS

Authors:: Travaš-Sejdić, Jadranka (186622); Jelenčić, Jasenka (41450); Bravar, Mladen (5281); Frobe, Z.

Journal: European Polymer Journal
Number: 0
ISSN: 0014-3057
Volume: 31
Year: 1995
Pages: from 0 to 0
Number of references: 19
Language: engleski
Summary: Zinc diethyldithiocarbamte (ZDEC) is one of the most commonly used accelerators in natural rubber latex technology because of good properties of the corresponding vulcanizates. Many studies using this accelerator have shown the presence of carcinogenic nitrosamines and therefore its unsuitability for production of some goods. Possibility of substitution of accelerator zinc diethyldithiocarbamate with zinc mercaptobenzothiazole, diphenylguanidine, or their combination, in vulcanization of NR latex films was investigated. Four series of ilms weere prepared by sulphur vulcanization, changing the accelerator and accelerator's concentration in latex composition. The data covering estimation of network structure through crosslink density and distribution of different crosslink type, mechanical properties, and resistance to heat and ozone degradation are presented. The influence of type and concentration of accelrrators on these properties of vulcanized films was considered. The results show that combination of accelerators zinc mercaptobenzothiazole/diphenulguanidine may be regarded as a proper substitute for zinc diethyldithiocarbamate as far as good film properties are desirable.
Keywords: natural rubber, N-nitrosamines, vulcanizate properties, network characterization, vulcanization accelerators

Title: MONITORING THE ESTERIFICATION OF SORBITOL AND FATTY ACIDS BY GAS CHROMATOGRAPHY

Authors:: Giacometti, Jasminka; Milin, Čedomila; Wolf, Nikola (54274)

Journal: Journal of Chromatographya
Number: 0
ISSN: 0021-9673
Volume: 704
Year: 1995
Pages: from 535 to 539
Number of references: 11
Language: engleski
Summary: Lauric acid esters of sorbitok, 1,4-sorbitan and 1,4:3,6 isosorbide were synthesized in laboratory. Esterification was carried out at 160C with a catalyst for sorbitol cyclization and esterification, viz., p-toluenesulfonic acid. Lipid classes and polyols were separated and analysed by GC as trimethylsilyl ethers and esters. The purpose of the study was to determine the suitability of GC analysis of these products as a means of following the progress of reactions. The results confirmed the possibility of monitoring lauric acid and sorbitol esterification via the GC determination of lauric acid concetration.
Keywords: lauric acid, sorbitol, gas chromatography

Title: INVESTIGATION OF THE INFLUENCE OF FILLERS 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)

Journal: Journal of Adhesion
ISSN: -
Volume: 47
Year: 1994
Pages: from 201 to 215
Number of references: 17
Language: engleski
Summary: The properties of poly(vinyl acetate) compositions prepared as potential wood adhesives were investigated. The paper presents the results of the influence of various kinds of inorganic fillers based on calcium carbonate and alumino-silicate and an organic filler, starch, oh the adhesive composition properties. The comparison among rheological behavior of the adhesive dispersions concerning the specific role of fillers were made. Mechanical and relaxation properties of the adhesive films could reveal the effect of filler characteristics on the polymer matrix. The significant influences of particle size distribution and specific surface area on the poly(vinyl acetate) adhesive composition were determined, along with other filler characteristics.
Keywords: poly(vinul acetate) adhesives, fillers, calcite, alumino silicates, starch, wood adhesive joint

Title: CORRELATION BETWEEN MECHANICAL PROPERTIES AND DEGRADTION PROCESSES OF POLY(METHYL METHACRYLATE-co-BUTHYL ACRILATE) FILMS

Authors:: Leskovac, Mirela (175223); Kovačević, Vera (74041); Stanojević, Duško (157596); Brajković, N.

Journal: Journal of Applied Polymer Science
ISSN: 0021-8995
Volume: 53
Year: 1994
Pages: from 1717 to 1721
Number of references: 13
Language: engleski
Summary: Copolymer systems based on various molar ratios of methyl methacrylate (MMA)/butyl acrylate (BA) and different mass content of N-methylolacrylamide (NMA), as a cross linking agent, were investigated. The influence of temperature, 150C, under conditions similar to those used in the textile industry, and effect of ultraviolet UV irradiation were examined. The changes of mechanical properties were found to be connected with the cross-linking and/or degradation mechanisms. The effect of copolymer composition on the mechanical properties was established, especially during UV degradation.
Keywords: copolymer systems, poly(methyl methacrylate-c-butyl acrylate, influence of temperature, UV irradiation, mechanical properties

Title: TERMALLY STIMULATED OXYDATIVE DEGRADATION OF HIGH IMPACT POLYSTYRENE WITH NITRIC ACID

Authors:: Hace, Drago (15006); Kovačević, Vera (74041); Pajc, Davorka; 0, 0

Journal: Polymer Engineering Science
Volume: 35
Year: 1995
Pages: from 0 to 0
Language: engleski
Summary: Process of thermo-chemical degradation and transformation of high impact polystyrene HPS and influences of concentrated nitric acid were investigarted by various temperature and time. Pure polystyrene and polybutadiene exposed under the same conditions were comparatively investigated. The mechanisms of simultaneous and/or preferable path of reactions based on IR, UV and 1NMR investigations were proposed. After fractionation of copolymer systems DSC, TGA and DMA, as well as mechanical and morphological measurements were made. Mechanisms of oxydation and nitration depend on temperature and lead to the molecular and chemical heterogenity. The mechanical properties were lowered as a consequence of degradation processes coused by medium nitric acid.
Keywords: high impact polystyrene HLPS, influence of agressive medium conc. HNO3, structural and morphological properties, mechanical properties, heterogenity

Title: PHOTOSTABILITY OF POLYURETHANE ELASTOMERS BASED ON TWO TYPES OF DIISOCYANATES

Authors:: Rek, Vesna (40741); Govorčin, Emi (127332); Sendijarević, Aiša; Sendijarević, Vahid; C. Frisch, Kurt

Journal: Journal of Elastomers and Plastics
Number: 4
ISSN: 0095-2443
Volume: 26
Year: 1994
Language: engleski
Summary: The effect of UV iradiation on the mechanical and thermomechanical properties of polyurethane (PU) elastomers and their morphology was studied. The chemical changes in the PU elastomers exposed to UV radiation were studied by means of Fourier Transform Inferared Spectroscopy (FTIR). The PU elastomers were based on an aromatic isocyanata (4,4'-diphenylmethane diisocyanata) and a cycloaliphatic isocyanata (4,4'dicyclohexylmethane diisocyanata). Poly(caprolactone) 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, prepolymers were prepared from poly(caprolactone) glycol by reacting with corresponding isocyanata at NCO/OH ratios of 2/1 and 4/1. The prepolymers were then chainextended with 1,4-butanediol and the mixture was press-molded in a platen press at 100C. The results showed that the stability of the investigated PY elastomers depend on the chemical structure of the diisocyanata and the hard/soft segment ratio. The processes of photooxidative degradation are more prevalent in PU elastomers based on cycloaliphatic isocyanata than those based on the aromatic isocyanata. In the case of PU elastomers based on the cycloaliphatic isocyanate it was found that the photodegradative processes were enhanced with increasing hard segment concentration. The degree of photooxidative degradation of PU elastomers, as studied by FTIR, correlated very well with the extent of morphological changes and changes in mechanical properties. Although PU elastomers based on the aromatic isocyanata undergo color changes, they exibited better retention of mechanical properties compared to those based on the aliphatic isocyanate.
Keywords: polyurethane, isocyanate componente, photodegradation, morphology, relaxation spectra, mechanical properties

Title: EXPERIMENTAL EVALUATION OF THE MICROWAVE DRYING OF LEATHER

Authors:: Skansi, Darko; Bajza, Željko (140705); Arapović, A.

Journal: Journal of the Society of Leather Technologists and Chemists
Volume: 79
Year: 1995
Number of references: 8
Language: engleski
Summary: The microwave drying of industrially prepared leather has been experimentally investigated on a laboratory scale. The experiments were performed at three different levels of microwave heating power. measuring the mass of the sample through the drying duration, the kinetic drying curves were obtained. For correlation of experimental results the exponential model X= (a-Weq).exp(-b.td)-Xeq and its differential form has been applied. Results obtained show a high level of correlation, and a strong relationship between applied microwave power and drying time (rate), type of leather sample and their pretreatment (vacum and sidewise dewatering).
Keywords: drying, kinetics, leather, microwave heating

Title: THE EXTRACTION OF SODIUM AND POTASSIUM PICRATES WITH POLY(BENZO-15-CROWN-5)MALEIMIDE), POLY(BENZO-15-CROWN-5-)MALEIMIDE-ALT-a-METHYLSTYRENE) AND BENZO-15-CROWN-5

Authors:: Fleš, Dragan; Hace, Drago (15006); Vuković, Radivoje; Flesh, Dragan

Journal: Polymer Bulliten
Volume: 33
Year: 1994
Pages: from 425 to 430
Number of references: 8
Language: engleski
Summary: The distribution of complexes of sodium picrate and potassium picrate with poly(benzo-15-crown-5)maleimide), poly(benzo-15-crown-5)maleimide-alt-a-methylstyrene) and benzo-15-crown-5(b15/5) between water and CH2Cl2 was investigated. Concentration of na-ion with homopolymer in CH2Cl2 was 52%, while the concentration of complex of alternating copolymer and b15/5 with na-ion was 22% and 20% respectively,. Concentration of K-ion complex in CH2Cl2 with homopolymer and alternating copolymer was 90% and with b15/5 the concentration of complex was 40%. The large difference in the complexation ability of Na-ion and K-ion with homopolymer and alternating copolymer is considered to be the consequence of the formation of 1:1 complex with Na-ion and 2:1 complex with K-ion.

Title: THE APPLICATION OF TAFT-HANCOCK STERIC CONSTANTS TO THE FREE-RADICAL INITIATED COPOLYMERIZATION OF N-ALKYLMALEIMIDES WITH ALFA-METHYLSTYRENE

Authors:: Flesh, Dragan; Hace, Drago (15006); Ranogajec, Franjo; Vuković, Radivoje

Journal: Polymer Bulletin
Volume: 33
Year: 1994
Pages: from 445 to 449
Number of references: 10
Language: engleski
Summary: The rates of free-radical initiated alternating copolymerization of alfa-methylstyrene with N-alkylmaleimides (RMI) decrease in the following order: me>Et>Pe-n-Bu-n-Hex>iso-Pr>tert-Bu. A linear relationship was established in the plots of log(kR/kMe) against polar substituent constants gama*, "true steric" factors ES and corrected steric factors ESC. The best fit was obtained in plots of log (kR/KMe) against sigma* and ESC while a large scattering of results was observed in the plot of log(kR/KMe) against ES.

Title: THERMAL PROPERTIES OF POLY(4'-N(BENZO-15-CROWN-5)MALEIMIDE) AND COPOLYMER WITH ALFA-METHYLSTYRENE

Authors:: Flesh, Dragan; Hace, Drago (15006); Vuković, Radivoje

Journal: Polimeri
Number: 4
ISSN: 0351-1871
Volume: 15
Year: 1994
Pages: from 126 to 128
Number of references: 8
Language: engleski
Keywords: activation energy, poly(benzo-15-crown-5)maleimide), poly(benzo-15-crown-5-)maleimide-alt-alfa-metilstyren), pre-exponential factors, reaction rate, thermal stability

Title: EXPERIMENTAL EVALUATION OF THE MICROWAVE DRYING OF LEATHER

Authors:: Skansi, Darko

Journal: Journal of the Society of Leather Technologists and Chemists
Volume: 79
Year: 1995
Language: engleski
Summary: The microwave drying of industrially prepared leather has been investigated on a laboratory scale. The experiments were performed at three different levels of microwave heating power. Measuring the mass of the sample through the drying duration, the kinetic drying curves were obtained. For corelation of experimental results the exponential model X=(a-Xeq).exp(-b.td)-Xeq and its differential form has been applied. Results obtained show a high level of correlation, and a strong relationship between applied microwave power and drying time (rate), type of leather sample and their pretreatment (vacuum and sidewise dewatering).

Title: DEGRADATION OF POLYURETHANE

Authors:: Rek, Vesna (40741)

Number: ani
Volume: 11 D
Year: 1993
Pages: from 5 to 6
Number of references: 107
Language: hrvatski


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