Back SearchTitle: POLYMERISATION KINETICS AND MOLECULAR CHARACTERISTICS OF 'NEODYMIUM' POLYBUTADIENE: INFLUENCE OF HALOGENATING AGENT CONCENTRATION
Page Range: p.T/1-5
Author(s): Akhmetov I G; Kozlov V G; Salakhov I I; Sakhabutdinov A G; D'yakonov G S
File size: 95K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
The polymerisation of butadiene in the presence of a catalytic system consisting of neodymium versatate, diisobutylaluminium hydride and hexachloro-p-xylene was studied with particular reference to the effect of the halogenating agent concentration on the kinetic laws governing the process and to the molecular characteristics of the polybutadiene formed. The concentration of the halogenating agent had a significant effect on the catalytic activity, maximum activity being achieved with Cl:Nd molar ratios of 2.4-3.0. Data on the MWD of polybutadiene, combined with kinetic parameters of the polymerisation process, confirmed the previous suggestion that the polymerisation of butadiene in the presence of the catalytic system studied proceeded on at least two types of active centres that differed in the probability of chain restriction. Variation of the Cl:Nd molar ratio led to a change in the concentration and ratio of different types of active centre. 9 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.7-10)
Title: PRODUCTION OF BUTYL RUBBER BY SUSPENSION POLYMERISATION USING A MODIFIED CATALYTIC SYSTEM
Page Range: p.T/7-10
Author(s): Markina E A; Chelnokova S Z; Sofronova O V; Akhmed'yanova R A; Ziyatdinov A S; Shiyapov R T; Sakhabutdinov A G; Gil'mutdinov N R; Gil'manov K K
File size: 76K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
The introduction of the optimum amount of isoprene into the aluminium chloride-based catalytic complex used in the synthesis of butyl rubber was shown to make it possible to conduct copolymerisation under more stable conditions and with high isobutylene concentrations. This made it possible to increase the polymer yield while retaining the optimum characteristics and physical properties of the polymer. The physicomechanical properties of butyl rubber obtained using the modified catalyst system were found to be similar to those of butyl rubber produced under normal conditions. 9 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.10-13)
Title: POLYMERISATION OF ISOPRENE ON A SODIUM-MAGNESIUM CATALYTIC SYSTEM. INFLUENCE OF THE POLYMERISATION CONDITIONS ON THE MICROSTRUCTURE AND MOLECULAR WEIGHT CHARACTERISTICS OF 3,4-POLYISOPRENE
Page Range: p.T/11-14
Author(s): Tverdov A I; Otvalko Z A; Mironyuk V P; Kuz'min S V
File size: 67K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
The molec.wt. characteristics and microstructure of 3,4-polyisoprene obtained on a sodium-magnesium catalytic system were shown to be influenced by the concentration of the catalyst and the ratio of its components, the monomer content in the charge and the polymerisation temperature. By varying these factors, it was possible to produce 3,4-polyisoprene with a wide range of molec.wts. (from 20,000 to 250,000) and a content of vinyl units of 48-90 wt %. 13 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.13-16)
Title: INFLUENCE OF THE MACROMOLECULAR STRUCTURE OF POLYMERS ON THE PROPERTIES OF MULTICOMPONENT THERMOPLASTIC ELASTOMER COMPOSITES
Page Range: p.T/15-19
Author(s): Novokshonov V V; Glukhov V V; Kropachev R V; Musin I N; Kimel'blat V I
File size: 136K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
The influence of the macromolecular structure of the rubbers on the properties of three-component thermoplastic elastomers (TPEs) was studied. The investigation was conducted on blends of LDPE with nitrile rubber and with one of three ethylene-propylene-diene terpolymers. Chemical modification (partial crosslinking) was shown to be a reasonably effective means of optimising the macromolecular structure of the initial polymers. By careful selection of the initial components and use of chemical crosslinking, it was possible to improve the strength properties of TPEs by a factor of 2 to 3. Macromolecular design also affected the high-elastic characteristics and oil resistance of composites. In analysis of the results obtained, however, it was also necessary to take into account the variations in the molecular composition of the initial polymers and the monomer distribution along the macromolecular chain. 11 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.16-20)
Title: PRODUCTION OF MODIFIERS OF THE RESORCINOL-UROTROPIN TYPE ON THE BASIS OF NEW NITROGEN-CONTAINING HETERORINGS
Page Range: p.T/21-23
Author(s): Logvinova M Y; Shukkur A K; Sakharova E V; Potapov E E
File size: 61K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
Complexes for chemical modification of vulcanisates were synthesised by the interaction of equimolar aqueous solutions of resorcinol and nitrogen-containing heterorings, e.g. teotropin, homourotropin and benzohomourotropin. IR spectroscopy, elemental analysis and mass spectrometry were used to study the molecular complexes. The formation of molecular complexes was shown to be due to the emergence of a strong, highly ionic, hydrogen bond between the components. Vulcanisates modified with a molecular resorcinol-benzourotropin complex were superior in nominal strength, temperature resistance and tear strength to vulcanisates modified with resorcinol-urotropin. In the thermal decomposition of a molecular resorcinol-benzourotropin complex, no ammonia was released. 7 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.22-24)
Title: LIQUID-PHASE FILLING OF SOLUTION BUTADIENE-STYRENE RUBBERS WITH SILICAS
Page Range: p.T/25-27
Author(s): Rakhmatullin A I; Eliseeva I V; Kazakov Y M; Mashchenko V I; Gafarov A M
File size: 180K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
A method was developed for the liquid-phase filling of solution butadiene-styrene rubbers with silicas, involving mixing of a 10-30% solution of rubber in hexane with suspensions of silica of different concentration in the same solvent. The composites were prepared in equipment with stirrers and in a vacuum mixer. Parameters optimised included rotational speed of the stirrer or rotors, mixing temperature, time and pressure, and the order of introduction of the components of the composite. The vulcanisation characteristics and physicomechanical properties of the vulcanisates based on the developed composites were studied and compared with those of composites produced by Degussa AG. 7 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.24-26)
Title: NEW TECHNOLOGICALLY ACTIVE ADDITIVES FOR RUBBER MIXES BASED ON BUTADIENE-ACRYLONITRILE RUBBERS
Page Range: p.T/29-32
Author(s): Ushmarin N F; Kol'tsov N I
File size: 67K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
Effective technologically-active additives were developed which comprised polydispersed compositions based on well-known surfactants (Oksanol TsS-100 and Oksanol KD-6) and a number of ingredients used in the rubber industry, e.g. dark factice, processing aids, neutral filler. Depending on their composition, these additives made it possible to improve the processing properties of rubber mixes based on BNK butadiene-acrylonitrile rubbers and to stabilise the output characteristics of vulcanisates and the quality of articles based on them. 2 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.26-29)
Title: STUDY OF THE REACTIVITY OF TETRAALKOXYSILANES ON INTERACTION WITH SILOXANOLS
Page Range: p.T/33-36
Author(s): Boev V V; Kopylov V M; Kovyazin V A; Sokol'skaya I B; Astapov B A
File size: 78K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
A study was conducted of the reactivity of tetrakis(2-aminoethoxy)silane, tetrakis(2-methoxyethoxy)silane, tetrakis(2-ethoxyethoxy)silane and tetraethoxysilane on interaction with low molec.wt. polydimethylsiloxane rubber with terminal hydroxyl groups, i.e. alpha,omega-dihydroxyoligodimethylsiloxane with a content of hydroxyl groups of 1.4%. It was shown that, in composites vulcanised by a polycondensation mechanism, tetrakis(2-aminoethoxy)silane could be used as a crosslinking agent in the absence of a catalyst, tetrakis(2-methoxyethoxyl silane in the presence of catalytic amounts of alpha,omega-bis(2-aminoethoxy)oligodimethylsiloxane and Si(OEt)"n(OCH"2CH"2OMe)"4"-"n and Si(OEt)"n(OCH"2CH"2OEt)"4"-"n in the presence of catalytic amounts of tin di(dibutyl octanoate), the content of which could be reduced by more than an order of magnitude compared with Si(OEt)"4. 7 refs. (Article translated from Kauchuk i Rezina, No.3, 2009, p.29-32)
Title: PRODUCTION OF A RUBBER-MIX SOFTENER BY PYROLYSIS OF USED TYRES
Page Range: p.T/37-40
Author(s): Minigaliev T B; Dorozhkin V P; Sukhova O A; Il'yasov R S; Mokhnatkina E G
File size: 73K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
A method developed by the authors for processing of used tyres by flue-gas pyrolysis of the rubber part at a temperature of 250-700 deg C for 2-10 h is described. The liquid phase produced was divided into light fraction (below 350 deg C) and a heavy fraction (above 350 deg C), and the heavy fraction was studied as a softener (KUB-PM) for rubber mixes. The properties of the softener were investigated and the performance of the softener in rubber mixes for radial lorry tyre sidewall, radial car tyre carcass and radial all-weather car tyre tread formulations, as a replacement for PIN-6 oil, was studied. Data on the processing, service properties and physicomechanical properties of the rubber mixes are presented and discussed. 7 refs. (Article translated from Kauchuk I Rezina, No.3, 2009, p.32-35)
Title: PREDICTING THE FATIGUE LIFE OF PNEUMATIC TYRES
Page Range: p.T/41-45
Author(s): Sokolov S L; Nenakhov A B
File size: 179K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
A procedure was proposed for assessing the fatigue life of pneumatic tyres on the basis of calculation of the stress-strain state (SSS) concentrations by the finite element method and experimental estimation of the fatigue strength of rubber-cord systems using rubber-cord specimens. The use of the procedure in pneumatic tyre design practice was examined. For its broad testing, a dataset on the SSS parameters of different types of tyre at points of SSS concentration, obtained by mathematical or experimental methods, was necessary. It was also essential to continue to obtain characteristics of the fatigue life of rubber-cord system (Woehler curves) for different types of SSS and the parameters of the deformation cycle. It was also necessary to establish the standard values of the fatigue life limit for different types of rubber. From the results of bench and service tests, standard values of the fatigue strength safety factor for different tyre parts could be determined. 7 refs. (Article translated from Kaucuk i Rezina, No.3, 2009, p.35-39)
Title: COARSE GRAINED SIMULATION STUDY FOR THE SURFACE AND INTERFACE OF THE POLYMERIC MATERIALS
Page Range: p.T/47-52
Author(s): Morita H
File size: 218K
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Issue Year: ipsat
Volume: 37
Issue No: No.3
Abstract
A review is presented of the literature on studies of molecular chain dynamics using coarse-grained molecular dynamics simulation of the measurement of Tg at a surface or interface and friction measurement by lateral force microscopy. Specifically, an outline is given of studies verifying Tg at the surface or interface of thin films of linear polymers and studies of polymer chain dynamics between a polymer thin film and atomic force microscopy probe. 21 refs. (Article translated from Nippon Gomu Kyokaishi, No.11, 2009, p.472-477)