Back SearchTitle: INFLUENCE OF MINERAL POWDERS ON SELECTED MECHANICAL PROPERTIES OF LINEAR LOW-DENSITY POLYETHYLENE
Page Range: T/1-7
Author(s): Goscianski M; Maciejewski; Gulinski J; Leda H
File size: 201K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
An investigation into the improvement in the mechanical properties of linear low-density polyethylene by the use of modified and unmodified mineral fillers, is reported. The aim of the study was the modification of polyolefins to achieve composites with controlled physico-mechanical characteristics. The mineral fillers selected were industrial talc, whiting, aluminium oxide and fly ash. For chemical modification of the powder fillers, Polish silane compounds were used, and comparative use was made of butylamine and triethanolamine as modifiers of the selected fillers. Changes in the morphology and microstructure of the filler surface were evaluated by use of elemental analysis, X-ray structural analyses, scanning microscopy, and measurement of the specific surface by measuring the sorption. To characterise the effect of the type of filler on the changes in phase structure of the LLDPE, observations were made concerning the changes in crystallinity, mechanical properties of the composites, and the topography of fracture surfaces and degree of homogeneity of the structure of the composites. Results indicate that inexpensive fillers with appropriate modification by silanes can be employed in composites with polyolefins to obtain plastics with good mechanical properties. 12 refs. (Article translated from Polimery, No. 1, 2004, pp.15.)
Title: EFFECT OF SELECTED AUXILIARY AGENTS ON THE PROPERTIES OF THE SURFACE LAYER OF EXTRUDED POLYETHYLENE
Page Range: T/8-13
Author(s): Gorbacz T
File size: 72K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
Thermoplastic coatings are used as outer layers on cable sheathing in the optocommunciations industry in order to provide improved properties such as reduced absorption and thus adhesion of impurities. However, polyethylene has a fairly high surface resistivity and readily accumulates a static charge on its surface. In order to overcome this, MDPE was modified with auxiliary agents, in particular, blowing agents and antistatic agents. A measure of the state of the outer layer of the coating on the cable sheathing is the free surface energy, which is used to assess phenomena associated with adsorption, wetting and adhesion. This work describes the effect of simultaneous modification of polyethylene with an antistatic agent and blowing agent, on the properties of the surface layer of an extrudate, by measuring the wetting angle and free surface energy. Results indicate that a content of blowing agent should not be greater than 0.2 - 0.3% by mass, and the right adhesion properties of the outer layer of MDPE, leading to a decrease in its wettability are achieved by using an antistatic agent containing hydroxylamine, triethanolamine and glyceryl monostearate in quantities of not less than 0.4% by mass in relation to the mass of the polymer. 22 refs. (Article translated from Polimery, No. 1, 2004, pp. 23.)
Title: ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE: THE NEW REALITY OF THE RUSSIAN POLYOLEFIN INDUSTRY
Page Range: T/14-16
Author(s): Maier E A; Dudchenko V K; Poddubnyak A N; Arkatov O L
File size: 53K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
The current state of production of ultrahigh molecular weight polyethylene in Russia is reviewed, with reference to the activities of the Tomsk Petrochemical Works Open Joint Stock Company. A pilot plant was constructed during the mid-1990s for the suspension polymerisation of ethylene. Use was made of titanium-manganese catalysts of the Institute of Catalysis of the Siberian Section of the Russian Academy of Sciences. In 2000, a unit of UHMWPE synthesis was put into service using a two-reactor layout which is illustrated. A description is given of the synthesis process, and details of the product obtained are included. The unit makes it possible to carry out the synthesis of UHMWPE in a periodic regime when the user needs a minimum amount of polymer with prescribed properties, or when it is necessary to test a new type of catalyst. However, it is reported that there is practically no domestic market for UHMWPE due to the lack of processing equipment. 6 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 3-4.)
Title: DIELECTRIC INVESTIGATIONS OF THE LOW-TEMPERATURE CURING OF EPOXY RESIN ED-20
Page Range: T/17-21
Author(s): Chernov I A; Deberdeev T R; Novikov G F; Garipov R M; Irzhak V I
File size: 115K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
The use is described of dielectrometry for the prediction and study of the transformation transitions through which a polymer passes during its formation. It is applied here to investigate the low-temperature curing of epoxy oligomer ED-20. The investigation showed that its free volume determined the relaxation behaviour of the system, and change in the free volume led to glass transition, and thereby to the inhibition of through conduction. Of particular note, is the splitting of the distribution of relaxation times into two maxima: low-frequency and high-frequency, which indicates, it is suggested, the non-equilibrium nature of the polymer system formed at low temperature. 11 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 5-8.)
Title: POLYPROPYLENE FIBRE WITH GRAFT STYRENE. PART 1
Page Range: T/22-24
Author(s): Novoselova L Y; Bordunov V V; Vinnichenko L I
File size: 48K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
An investigation is reported into the chemical modification of polypropylene fibres in order to produce highly acidic ion-exchange materials. To achieve this aim, it was necessary to select the appropriate modification conditions and to characterise the products obtained. Details are given of the graft copolymerisation of styrene to polypropylene fibrous material from PP product waste, which was carried out both in the presence of initiators (benzoyl peroxide and azobisisobutyric acid dinitrile), and without them. Highly acidic ion exchange fibres were produced by the sulphonation of grafting products with concentrated sulphuric acid. 5 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 9-10.)
Title: CALCULATION OF THE NECESSARY THICKNESS OF DECOMPOSING HEAT-PROTECTIVE POLYMER BASED COATINGS
Page Range: T/25-29
Author(s): Koptelov A A; Zelenev Y V
File size: 68K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
A method of calculating the necessary thickness of a polymer composite-based sacrificial heat protective coating is discussed. The aim of the work is to assess the influence of the kinetics and heat effect of thermal decomposition on the magnitude of the necessary thicknesses of polymer-based heat protective coatings under prescribed conditions of external heat exchange. Thus, with a known rate of thermal degradation of the coating derived from a given equation, it was possible to determine the temperature of the start of its decomposition, (Td). The thickness of the decomposed part of the coating could then be assessed from a further given equation. The values of Td for model heat protective coatings with different speeds of advance of degradation are tabulated. 8 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 11-3.)
Title: EFFECT OF THE INITIATING SYSTEM ON THE STRENGTH CHARACTERISTICS OF HIGHLY FILLED COMPOSITES BASED ON METHYL METHACRYLATE
Page Range: T/30-33
Author(s): Kholstinin V V; Kireev V V; D'yachenko B I; Rybalko V P; Prudskov B M
File size: 95K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
This work addresses the influence of the amount of and composition of the initiating system (benzoyl peroxide and dimethylaniline) on the process of formation of a polymer matrix based on methyl methacrylate, directly in the presence of a filler, with the aim of achieving the maximum mechanical properties of highly filled polymer composites. The filler used was a mixture of building sand and mineral powder. The influence of the amount of initiating system and the ratio of its components on change in the compressive strength of the polymers composites is claimed to be the result of differences in the properties of the polymer matrix formed (primarily the molecular weight), and the nature of interaction of the polymer with the surface of the filler. Changes in the strength characteristics and packing density of the polymer composites formed were analysed, and the results enable an optimum amount of components of the initiating system to be established. 4 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp.14-6.)
Title: MODIFICATION OF POLYPROPYLENE WITH BINARY MIXTURES OF CHEMICALLY ACTIVE COMPOUNDS
Page Range: T/34-37
Author(s): Galibeev S S; Kochnev A M; Spiridonova R R; Ryazapova L Z; Arkhireev V P
File size: 81K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
Work is described on the use of binary mixtures of chemically active compounds based on isocyanates, indoles, epoxides and lactams for the chemical modification of polypropylene. The components of the binary system were chosen in such a way that one of them at least was able to enter into chemical interaction with residual unsaturated end bonds in PP, which, being weak points of macromolecules, have a negative effect on the combination of properties of the polymer, in spite of their low content. As a result of the modification of crystalline PP with the selected binary system, the addition of individual components of the modifying mixture to the polymer occurred in a number of cases via their preliminary copolymerisation. Effects classified as additive, synergistic or superpositional in nature are examined. Overall, the effectiveness of binary systems based on chemically active compounds is concluded to be determined by the structure and properties of the products formed during their interaction with each other and with the polymer. 5 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 17-9.)
Title: FEATURES OF PROCESSES OF ADHESION OF POLYMER SOLUTIONS TO METALLIC SUBSTRATES
Page Range: T/38-43
Author(s): Dolomatov M Y; Timofeeva M Y
File size: 62K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
A semi-empirical thermodynamic model is proposed that describes the interaction of adhesive with substrate within the framework of concepts of adhesion as the isobaric expansion of a two-dimensional non-ideal polymer gas in the field of molecular forces of the substrate. The adequacy of the model is borne out by the linear dependence of adhesion on temperature and the non-linear dependence on the concentration of the polymer solution on metallic substrates, (bronze, carbon steel, titanium, aluminium) with aqueous polymer solutions of polyvinyl acetate and polymethyl cellulose used as the adhesives. 8 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 19-22.)
Title: KINETIC FEATURES OF THE HOMOPOLYMERISATION OF 2-HYDROXYETHYL METHACRYLATE IN VARIOUS MEDIA
Page Range: T/44-59
Author(s): Lavrov N A
File size: 133K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
Information is given on the kinetics of homopolymerisation of 2-hydroxyethyl methacrylate (HEMA) in various media. For polymerisation initiators, it was proposed to used peroxides, hydroperoxides, azo compounds and other compounds that can form active radicals when they break down. This paper considers the features of the production of soluble polymers based on HEMA; the kinetics of the homopolymerisation of HEMA in bulk and in organic solvents; and the kinetics of homopolymerisation of HEMA in aqueous and in aqueous-organic media. It is concluded that the nature of the solvent and initiating system has a considerable influence on the rate of polymerisation reactions and on the molecular weight of the polymers produced. By changing the nature of the reaction medium, it was possible to control the activity of the monomer, which is a useful process in the radical copolymerisation of HEMA. 53 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, pp. 25-35.)
Title: POLYHYDROXYETHERS AS AN INDUSTRIAL BASE MATERIAL
Page Range: T/60-61
Author(s): Averkin V N; Leus Z G; Plyashechnik N I
File size: 28K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
At NIIKHIMPOLIMER, polyhydroxyethers of a wide range of molecular weights have been synthesised. Synthesis is based on the catalytic copolymerisation of low molecular weight epoxy resin and bisphenols. The results of the research showed the suitability of various catalysts for the production of polyhydroxyethers with various molecular weights. The molecular weight of the products obtained was controlled by the ratio of epoxy resin and bisphenol, and also by the selection of the catalyst and polymerisation conditions. On the basis of the data obtained, a production process was developed and the production of polyhydroxyethers from resin ED-22 and diphenylolpropane of different molecular weight and with a dynamic viscosity of 30% solution in cyclohexanone at 25 degrees C from 1.8 to 4.0 Pas has been organised. 1 refs. (Article translated from Plasticheskie Massy, No. 8, 2003, p. 36.)
Title: EFFECT OF PROLONGED AGEING ON THE MECHANICAL PROPERTIES OF A NUMBER OF HEAT-RESISTANT POLYMERS
Page Range: T/62-65
Author(s): Askadskii A A; Baltushnikas A; Migonene Z B; Migonis R P
File size: 65K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
Following a brief market analysis of the demand, growth and total market share of heat resistant polymers, this paper concerns itself with an analysis of the effect of prolonged ageing on their mechanical properties. Due to their complicated synthesis and high price, it is important that these materials are used efficiently, and as such, attention is paid to the investigation of their mechanical relaxation properties, the determination of their mechanical service characteristics in extreme conditions, and the elucidation of various factors on performance. Reference is made to detailed studies conducted 20 years ago into the mechanical relaxation properties of heat resistant constructional polymers of aromatic structure with heterocycles in the main chain (polybenzoxazole (POB), polyoxadiazole (POD), and aromatic polyimide (PI-2).This present work deals with establishing the effect of natural long-term ageing over a period of 20 years on the strength and relaxation properties of these heat resistant materials to see if there are any changes in molecular structure. Results obtained 20 years ago and now are compared. 10 refs. (Article translated from Plasticheskie Massy, 2003, No. 10, p. 36-8.)
Title: KINETICS OF HYDROLYSIS OF ESTER GROUPS OF POLYESTER RESIN IN THE PRESENCE OF WATER-GLASS
Page Range: T/66-68
Author(s): Korol'kova N E; Kudyukov Y P; Belkina S D; Kudyukova G P; Chasnyk O F; Rymar T E
File size: 43K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
The use is discussed of water-glass in the creation of organosilicate compositions based on it, leading to the production of polymer composites with properties that are controllable over a wide range. Modifiers of water-glass include isocyanates, epoxy resins and compounds containing ester bonds. As a result of hydrolysis, the ester bonds produce carboxyl groups in the reaction mass, and these lower the acidity of the solution and cause enlargement and aggregation of the siliceous particles. This article describes the study of the hydrolysis of ester groups of P-7M resin in the presence of sodium silicate. Results revealed a high rate of hydrolysis due to the energy factor of the reaction. As such, compounds containing ester groups can be used as hardeners of water-glass compositions. In addition, the process of hardening of water-glass with water-soluble resins will be extended over time, providing advantages in terms of the pot life of these compositions. 6 refs. (Article translated from Plasticheskie Massy, 2003, No. 10, p. 38-40.)
Title: INCREASING THE INTER-PLY STRENGTH OF POLYESTER GRPs BY THE INSERTION OF ARAMID FIBRES
Page Range: T/69-72
Author(s): Radenkov F; Radenkov M; Marinova A; Topliiska A; Zhelyazkov Z
File size: 56K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
A method is proposed for the strengthening of glass reinforced polyesters. A disadvantage of laminated plastics is their low strength in inter-ply shear. The insertion of continuous fibres transversely in an orthotropic laminated composite results in a material with three-dimensional reinforcement. This work uses aramid fibres for this purpose. The mechanism of interaction of the unsaturated polyester binder with the aramid fibre in the presence of TDI is discussed, and the effectiveness of the insertion of aramid threads in orthotropic glass reinforced polyester is examined. It is shown that the inserted aramid fibres hamper the propagation of an inter-ply crack, and greatly increase the specific delamination resistance. 19 refs. (Article translated from Plasticheskie Massy, 2003, No. 10, p. 40-2.)
Title: POLYURETHANE ELASTOMERS FILLED WITH GRANULATED RUBBER
Page Range: T/73-76
Author(s): Czuprynski M
File size: 52K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
Reclaimed rubber granules were used as inert fillers in polyurethane elastomers, and tests were carried out to determine changes in mechanical properties. In particular, this article reports on the effect of rubber granules with diameters of 2 mm as a filler in polyurethane elastomer with a 12% concentration of free isocyanate groups. The results of strength tests carried out on specimens of polyurethane-rubber compounds are reported with reference to tensile strength and relative elongation at break, abrasion resistance and hardness. 24 refs. (Article translated from Polimery, 2004, 49, No. 2, p. 110-113.)
Title: CHARACTERISTICS OF SURFACE CONDITION OF SPECIAL SLIP LAYERS FORMED IN THE EXTRUSION PROCESS
Page Range: T/77-81
Author(s): Klepka T
File size: 114K
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Issue Year: ipsat
Volume: 31
Issue No: No. 5
Abstract
Multilayer extrusions provide the ability to construct outer layers with defined properties such as improved adhesion for printability. In order to obtain a polymer outer layer with precisely defined structure and properties, an understanding of the mechanisms of the interphase interactions in multi-component systems, is required. This paper investigates the interactions occurring in multi-component systems at the molecular level using spectroscopic techniques. Methods of forming slip layers are described, together with the characteristics and effectiveness of special slip emulsions for spray coating based on aqueous emulsions of polydimethylsiloxane oils. 12 refs. (Article translated from Polimery, 2004, 49, No. 2, p. 123-7.)