Back SearchTitle: INFLUENCE OF THE STRUCTURE OF AMINE CATALYSTS ON THE REACTIVITY OF ISOCYANATES IN URETHANE FORMATION
Page Range: T/1-6
Author(s): Guzikhin V A; Zayats M Y; Lyamkin D I; Chimishskyan A L; Orlov S I
File size: 63K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
An investigation is reported into the influence of the nature of amine catalysts used in the production of urethane systems, on the kinetics of interaction between the isocyanate and the hydroxyl-containing components of the formulation. The activity and selectivity of the catalyst are known to be determined primarily by the structure of its molecules. For a comparative assessment of the activity of the amine catalyst, used was made of the rheological method developed for model solution of interacting components in acetone. The hydroxy-containing component was polyether polyol and the isocyanate component was TDI. For a comparative assessment of the effectiveness of different catalysts in urethane formation use was made of the absolute increase in viscosity of the reaction mass as a result of microgel formation, which characterises the selectivity of urethane formation. On the basis of the developed procedure, a study was made of the effect of a number of amine catalysts, the analysis of which in model reaction, makes it possible to predict their behaviour in real polyurethane systems, and to simplify the route of formulation. 6 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.2-6)
Title: DINELAST - A PROMISING ELASTOMER FOR HOSE PRODUCTION
Page Range: T/7-8
Author(s): Nesterova L A; Reznichenko S V; Lysova G A; Sukhinin N S; Morozov Y L
File size: 35K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
To replace chloroprene rubbers in the production of oil- and petrol-resistant mechanical rubber goods, a new chlorine-containing rubber, - Dinelast 1815 is proposed. It is a ternary copolymer of butadiene, acrylonitrile, and vinylene chloride, which is claimed to combine oil and petrol resistance with good dynamic strength. This work reports on a study to investigate the possibility of using Dinelast 1815 in the production of rubber mixes for the outer layer of hose. 7 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.6-8)
Title: INFLUENCE OF DIFFERENT COUPLING AGENTS ON THE PROPERTIES OF SILICA-CONTAINING RUBBER COMPOUNDS BASED ON MODIFIED RUBBERS OBTAINED BY EMULSION AND SOLUTION POLYMERISATION
Page Range: T/9-13
Author(s): Kondrat'eva N A; Sigov O V; Gusev Y K; Kondrat'ev A N; Mironova E F; Glukhovskoi V S; Zeleneva O A; Shutilin Y F
File size: 45K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
Silica filled rubber compounds for the tyre industry are studied with reference to development work to improve filler dispersion and molecular interaction. The work involved the use of modified rubbers and coupling agents, and focused on butadiene-styrene rubber obtained by emulsion polymerisation, modified with polar monomer methyl methacrylate, and know as Rezilast-2, and DSSK-18f rubber, obtained by solution polymerisation, modified by the introduction of end dimethylamino groups. The use of modified rubbers obtained by emulsion and solution polymerisation is shown to promote an increase in the interaction between the rubber and the silica filler, and the use of coupling agent AGM-9 makes it possible to obtain rubber compounds with good strength characteristics, abrasion resistance and high elastic characteristics. However, the rubber compounds filled only with silicon dioxide do not fully satisfy the requirements of the tyre industry, and a combination of fillers and coupling agents was subsequently used, and the use of blends of Rezilast-2 and DSSK-18f was shown to provide a more balanced combination of properties with particular reference to abrasion resistance, processability, high strength, and low hysteresis losses. 6 refs.(Article translated from Kauchuk i Rezina, No.4, 2001, pp.8-11.
Title: INFLUENCE OF THE DEGREE OF CHLORINATION ON THE STRUCTURE AND FLAME RESISTANCE OF COMPOSITES BASED ON CHLOROSULPHONATED POLYETHYLENE
Page Range: T/14-18
Author(s): Donskoi A A; Shashkina M A; Zaikov G E; Aseeva R M
File size: 55K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The properties of materials based on chlorosulphonated PE depend on the degree of chlorination and the production method of the polymer. The influence of these factors on the low and high temperature resistance of materials was studied on a series of modified polymers based on HDPE, and with chlorine contents varying from 0 to 59 wt.%. Change in the structure of the polymer during chlorination is indicated by change in the shear modulus at 20 degrees C. It was shown that crystalline HDPE loses crystallinity as the degree of chlorination increases and is converted into an entirely amorphous polymer at a chlorine content of over 30 wt.%. After this critical chlorine concentration, changes in the nature of the dependencies of density and elastic modulus were noted, and also the degree of chlorination was shown to considerably affect the kinetics of thermal breakdown. 14 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.11-5).
Title: FILLED EMULSIONS AS MODELS OF INCOMPATIBLE POLYMER BLENDS
Page Range: T/19-22
Author(s): Kiselev V Y
File size: 61K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The influence is investigated of the use of polar and non-polar fillers as stabilisers of incompatible components in polymer blends. The study involves the identification of the dependence of the properties of the filled emulsion on the ratio of phases and the concentration and nature of the filler in order to select the optimum composition of the incompatible components and to characterise the surface state of the filler. 12 refs. (Article translated from Kauchuk i Rezina, No.4, 2002, pp.15-9).
Title: ORIENTATION ORDERING IN ELASTOMER-SHORT FIBRE COMPOSITES
Page Range: T/23-26
Author(s): Gabibullaev I D; Ionov N V
File size: 64K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
Properties of composite materials based on polychloroprene reinforced with short nylon 6,6 fibres, especially with respect to anisotropy, depend on the production conditions, and it was therefore proposed to examine the processes of formation of the anisotropic structure of elastomers filled with short fibres (EFCs), as the combination of a number of orientation processes. These include the orientation of macromolecules as a whole, structural physical formations, structures formed by finely dispersed fillers, anisotropic fillers, fragments of macromolecules and crosslinks adsorbed and chemisorbed on the fillers. 10 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.19-22)
Title: PROPERTIES OF SEALANTS BASED ON A COPOLYMER OF POLYSULPHIDE AND EPOXY RESIN
Page Range: T/27-30
Author(s): Khakmullin Y N; Kurkin A I; Liakumovich A G; Ionov Y G
File size: 59K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
To overcome some of the adhesion problems relating to the use of sealants based on liquid Thiokol polysulphide rubber, copolymers of polysulphide and epoxy-bisphenol A resins were evaluated for their adhesion to duralumin. Curing of such sealants involved the incorporation of an activating group combined with industrial vulcanising paste No.9, which made it possible to carry out the curing of sealants based on copolymeric Thiokol within the framework of schedules characteristic of Thiokol sealants used in engineering and aviation. 7 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.22-4).
Title: SIMULATION OF STRUCTURE OF BINARY SYSTEMS
Page Range: T/31-34
Author(s): Karpukhin A A; Mikheeva M A
File size: 86K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The aim of this research was to simulate the structure of a binary systems and to find the characteristics of the investigated structure. Percolation theory is used to seek a correlation between the geometric and physical characteristics, and makes it possible to model the structure of the multicomponent composite and its statistical characteristics. The effect of varying degrees of filling on the structure of the composite and in turn on its properties is studied, and account is taken of the topology of the aggregates. The effectiveness of the filler is determined by the degree of aggregation of its particles and therefor, an analysis of the structure of the sol fraction is made. 2 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.25-8)
Title: WORK OF FRICTION AT THE TYRE CONTACT AS A CRITERION OF TREAD WEAR
Page Range: T/35-38
Author(s): Gudkov V A; Trnovskii V N; Tret'yakov O B; Shiryaev S A
File size: 38K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The contact zone between the tyre and road surface is affected by a complex pattern of distribution of normal and tangential stresses and also slip, which is the main cause of tread wear. Tread wear resistance is tested under conditions of road and bench testing. In the bench tests, the main tyre loading conditions during service were simulated, making it possible to fairly accurately determine the wear resistance of the tread, and establish a correlation relationship between road and bench tests of tyres. The importance of the work of friction in the contact zone in assessing tread wear is emphasised, and also the properties of the tread rubber used, in particular, its fatigue life under repeated loading. For each tyre variant, on the basis of bench test data, it is shown to be possible to calculate the proportionality factor between tread wear and the work of friction at the contact zone. 3 refs. (Article translated from Kauchuk i Rezina, No.4, 2001, pp.33-5)
Title: INFLUENCE OF THE DEGREE OF STRUCTURE OF HIGH-POROSITY FURNACE BLACK ON THE REINFORCEMENT OF ELASTOMERS
Page Range: T/39-40
Author(s): Nikitin Y N
File size: 22K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The nature of the influence of the degree of structure of high porosity carbon black on the reinforcing effect in elastomer compounds, is shown to depend on the composition of the vulcanising group. With an optimum degree of filling, the tensile strength of sulphur vulcanisates increases with an increasing degree of dispersion of carbon black, and that of resinous vulcanisates increases with an increasing amount of occluded elastomer, with displacement of the optimum filling towards higher values. With increases in the degree of structure of carbon black, the region of optimum filling of the elastomer is broadened. 5 refs. (Article translated from Kauchuk i Rezina, No.4, 23001, pp.44-5)
Title: BLOCK COPOLYMER AS A COMPATIBILISER IN RUBBER BLENDS
Page Range: T/41-47
Author(s): Kawazura T
File size: 156K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The use is examined of block copolymers as compatibilisers for blends of incompatible rubbers. A description is given of the effects when a block copolymer comprising two diene rubber blocks is added to an incompatible diene rubber blend system. Several block copolymers with varying degrees of styrene contents are investigated as compatibilisers for an NR-S-SBR system with respect to their effect on phase structure and properties of rubber materials. 18 refs. (Article translated from Nippon Gomu Kyokaishi, No.6, 2001, pp.323-9).
Title: EPOXY CONTAINING POLY-N-VINYLPYRROLIDONE
Page Range: T/48-54
Author(s): Shtil'man
File size: 74K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The use is studied of epoxy-containing polymers as potential carriers for drug delivery, with particular reference to the production of epoxy-containing derivatives based on polymers with a known molecular weight distribution, such as poly-N-vinylpyrrolidone, (PVP) a polymer, already employed in the composition of medicinal drug preparations. This work reports on the investigation into the possibility of introducing epoxy groups into this polymer by using Dorsen's reaction, and provides details about the structure of the products that form during interaction of PVP with chloroacetamide, and additionally investigates how the conditions in which the process is carried out affect its course. 11 refs. (Article translated from Plasticheskie Massy, No.7, 2001, pp.5).
Title: INFLUENCE OF COMPLEX COMPOUNDS OF RHENIUM (V) AND MOLYBDENUM (V) WITH MACROCYCLIC LIGANDS ON PROCESSES OF STRUCTURISATION OF AN EPOXY POLYURETHANE BINDER RESIN
Page Range: T/55-60
Author(s): Verbitskaya N A
File size: 119K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
An investigation is attempted of the influence of the nature of the crosslink complexes of rhenium (V) and molybdenum (V) with macrocyclic ligands: 18-crown-6 and diaza-18-crown-6 (respectively) on the process of structurisation of a multicomponent system, an epoxypolyurethane binder resin, (VSO-200). It is concluded that these complex compounds, when they interact with the components of VSO-200 binder, perform the role of co-hardeners, promoting the formation of additional crosslinks. However, when the additional co-hardener is present, the degree of curing of these complexes, is less than for composites without additions. This is explained by steric factors, caused by the presence of the complex compound in the crosslinks. 13 refs. (Article translated from Plasticheskie Massy, No.7, 2001, pp.10).
Title: MATHEMATICAL MODELLING OF THE CONTROL OF PROPERTIES OF POLYMERIC MATERIALS
Page Range: T/61-65
Author(s): Komissarov Y A; Zelenev Y V; Degtyarev V G
File size: 40K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
A mathematical model is proposed for the characterisation of polymer properties controlled by means of physical modification. The physical modification includes a combination of heat treatment n cascade annealing conditions with the simultaneous action of force fields. Qualitative description of the processes of physical modification employs multiparametric control. This makes it possible to accomplish mathematical modelling of control of the properties of polymeric materials by varying four parameters: heating rate, heat treatment temperature and time, and cooling rate. The investigations were carried out on four films of non-crystalline PMMA. 7 refs. 9. (Article translated from Plasticheskie Massy, 2001, No.7, p.14-7).
Title: EFFECT OF TEMPERATURE ON THE RATE CONSTANTS OF LINEAR CHAIN TERMINATION IN 3D POLYMERISATION OF DIMETHACRYLATES
Page Range: T/66-70
Author(s): Kitsya A R
File size: 59K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The rate constants of linear termination of the primary and secondary chains of four dimethacrylates at 15 and 25 degrees C were determined experimentally, from the data of a dark process of polymerisation (after excluding UV radiation). A decrease of primary and secondary chains with rising temperature was observed for this material in the range from 15 to 25 degrees C. Results obtained are claimed to show that linear chain termination is a complex physical process, and emerges as an event of self-concealment of the active centre of the radical, the probability of which depends both on the concentration of traps and on their energy state. 14 refs. (Article translated from Plasticheskie Massy, 2001, No.7, p.18-20).
Title: GRADIENT POLYMER COMPOSITES WITH CONTROLLABLE ELASTIC MODULUS
Page Range: T/71-77
Author(s): Askadskii A A
File size: 93K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
This work investigates the principal characteristics relating directly to technology for the production of gradient polymer composites. Crosslinked polyisocyanurate polymers were used as the binder, with a composition that can be varied at will, based on 2,4-TDI and low molecular rubber. A gas-filled foamed flexible PU foam was investigated as the carrier-filler. The technology is described for the production of polymer composites based on cellular polyisocyanurate polymers, using the solution method of combining the binder with the carrier-filler, with processing into finished articles by hot pressing to produce gradient polymer composites and articles with controllable elastic modulus in the range from 2.2 to 1930 MPa within a single article. 6 refs. (Article translated from Plasticheskie Massy, 2001, No.7. p.21-6).
Title: INFLUENCE OF VARIOUS FACTORS ON THE CURING OF SODIUM-SILICATE-BASED COMPOSITES CURED BY CARBON DIOXIDE
Page Range: T/78-82
Author(s): Mazhirin P Y
File size: 90K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The influence is investigated of a number of factors on the curing of composites based on sodium silicate. The kinetics of curing and structurisation of the polymer matrix was assessed on the basis of an indirect indicator: the breaking stress during compression of standard specimens prepared from the composite under investigation, based on sodium silicate and a dispersed mineral filler after curing with carbon dioxide at various intervals. Factors investigated included: content of binder; basicity or ratio of the sodium silicate; the use of modifiers including organic and inorganic salts, NaOH and furfuryl alcohol, as well as products of their interaction (furfuryl alkali), and the content of these modifiers in the binder; and the nature of the dispersed mineral filler. It is claimed that the strong influence of salt effects in the curing of the composites based on sodium silicate has been established for the first time, and that new modifying combinations based on furfuryl alcohol have been synthesised and found to be effective. The properties of the composites based on the new polymer matrix and SiO2 and ZrSiO4 fillers are assessed and found to be promising for applications such as soil stabilisation by gas silication and in the development of heat resistant structural materials.9 refs. (Article translated from Plasticheskie Massy, 2001, No.7, p.26-9).
Title: SILSESQUIOXANES. 2. POLYSILSESQUIOXANES
Page Range: T/83-91
Author(s): Lesniak E
File size: 85K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The nature, properties, synthesis and applications of polysilsesquioxanes are discussed in some detail. Polysilsesquioxanes are generally accepted to denote polymers built up from silsesquioxane units (called T units), represented by the general formula RsiO1.5, and linked to each other in a ladder structure. Detailed descriptions are given of methods of synthesis of ladder-form silsesquioxanes, mainly polyphenylsilsesquioxanes and polymethylsilsesquioxanes, their properties and structures and application trends. 90 refs. (Article translated from Polimery, No.9, 2001, p.582).
Title: EFFECT OF THE STRUCTURE OF RIGID POLYURETHANE FOAMS FOAMED WITH A HYDROCARBON BLOWING AGENT ON THE APPARENT CONDUCTIVITY OF THE FOAM
Page Range: T/92-98
Author(s): Debski K; Magiera J; Pielichlowski J
File size: 95K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
Results are presented of a study of the effect of the apparent density on the thermal conductivity of rigid PU foams foamed with a mixture of pentanes. A critical comparison is included to identify the suitability of known models from the literature for the determination of the values of the coefficient of thermal conductivity of PU foams. Measurements were carried out using a Fox 200 made by Lasercomp which includes Peltier modules which permit measurements to be made under conditions of heat flow in two directions. The method of measuring the value of the coefficient of thermal expansion comprises the determination of the amount of heat flowing through the material in unit time during steady flow of the heat when a temperature difference has been set up along opposite sides of the specimen. These measurement results are compared to those found in the literature, and of all the models published and the equation describing them, it is proposed that only the Glicksman model shows good agreement. 23 refs. (Article translated from Polimery, No.9, 2001, p.631).
Title: INFLUENCE OF THE METHOD OF FEEDING THE POLYMER INTO THE INJECTION MOULD CAVITY ON THE STRUCTURE AND CRYSTALLINITY OF HIGH DENSITY POLYETHYLENE
Page Range: T/99-102
Author(s): Bociaga E
File size: 65K
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Issue Year: ipsat
Volume: 29
Issue No: No. 3
Abstract
The injection moulding of HDPE is discussed with reference to the method of cavity feeding, and its influence on the structure and crystallinity of the polymer. The formation of weld lines from the use of inserts or from feeding the plastic into the mould cavity at several points, is examined with respect to the mechanical properties of mouldings with weld lines. The present study compares the morphology of mouldings obtained using different methods for feeding the plastic into the injection mould cavity, i.e., from one or from both sides of the cavity. The degree of crystallinity of the plastic at different points of the moulding is also determined. 9 refs. (Article translated from Polimery, No.9, 2001, pp.638).