Back SearchTitle: COMPOSITES MADE FROM THERMOPLASTIC POLYMERS WITH CARBON NANOTUBES
Page Range: T/1-9
Author(s): Poetsche P; Leibnitz A J; Bhattacharyya A A; Goering H
File size: 266K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
This article investigates the use of carbon nanotubes as conductive reinforcement fillers for thermoplastic composites. The use of both multiwalled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) is examined, and their incorporation into polycarbonate and nylon-12 matrices is described. The use of melt processing is shown to provide an optimum method of achieving uniform distribution of the carbon nanotubes. The use of masterbatch technology is also discussed for the production of conductive composites. Consideration is given to various aspects of wetting, dispersibility, and interfacial adhesion. 8 refs. (Article translated from Gummi Fasern Kunststoffe, No.1, 2005, p.45-51)
Title: IMPROVING CUT/CHIP/CHUNK RESISTANCE IN TRUCK TYRES BY THE USE OF PARA-AMID CHOPPED FIBRES
Page Range: T/10-18
Author(s): Datta R N
File size: 169K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
Road and bench tests were performed on truck tyres which incorporated small additions of chopped fibres obtained from poly-(paraphenylene terephthalamide) (PPTA), POLY-(metaphenylene isophthalamide) (MPIA) and co-poly-(paraphenylene/3,4'oxydiphenylene terephthalamide) (PP/ODPTA). These chopped aramid fibres were used in typical compounds for truck tyres with the objective of improving cut/chip/chunk resistance , together with hysteresis, heat build-up, and other dynamic properties. Details are given of compounding and curing, formulations, and the optimisation of the formulations by reducing the amount of carbon black. Test results are discussed, which show that in addition to the improvements in cut/chip/chunk resistance, the rolling resistance and hence fuel consumption was also significantly improved. 8 refs. (Article translated from Gummi Fasern Kunststoffe, No.2, 2005, p.109-14)
Title: STUDY OF THE EFFECT OF RADIOLYSIS ON THE MOLECULAR TOPOLOGICAL STRUCTURE OF POLYETHYLENE BY THERMOMECHANICAL SPECTROSCOPY
Page Range: T/19-28
Author(s): Ol'khov Y A; Smirnov Y N; Ol'khova O M; Allayarov S R
File size: 135K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
In this report, the method of thermomechanical spectroscopy (TMS) has been used in the analysis of the molecular topological structure of HDPE powder after its gamma radiation treatment in air. Before thermomechanical analysis, the PE powder was compression moulded, and in the form of a cylinder with plane-parallel faces, was places in a thermal analyser. The property of some crystallising polymers such as PE to change their isotropic, topological structure when exposed to a uniaxially directed mechanical load is generally known. This results in, not only a change in the degree of crystallinity of the polymer, but also a change in the orientation of the direction vector of the longitudinal axis of its crystallites in relation to the vector of the pressure applied to the polymer. As a result, a certain proportion of the crystallites are oriented irreversibly in a plane perpendicular to this vector, and the topological structure of the polymer is transformed from isotropic to anisotropic. The thermomechanical analysis of polymers, based on recording their uniaxial strain during heating, makes it possible to carry out a quantitative estimate of the degree of isotropic-anisotropic transformations in the structure of the polymer. It is based on the different deformability of the polymer during melting of its crystallites and the recording of its deformability with different orientations of the vector of axial directionality of the crystallites towards the vector of the thermomechanical load applied during thermomechanical analysis. Conclusions resulting from the analysis of the molecular topological structure of HDPE after compression moulding at optimised pressure and gamma radiation, are discussed. 13 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.6-12)
Title: THE EFFECT OF MODIFICATION OF POLYMERS ON THEIR STRUCTURE AND PROPERTIES
Page Range: T/29-37
Author(s): Shevelev A Y; Zeleneva T P; Zelenev Y V
File size: 121K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
This article reviews the use of modification techniques in order to change the structure and properties of polymers. It includes an extensive description of the various classifications of polymers with reference to molecular structures. Consideration is given to both single- and multi-component structures, and copolymers. On the basis of the examined classification of polymeric systems, materials were selected for investigation which were of both scientific and practical interest. From the single-component systems, amorphous polystyrene and PMMA were chosen. For multicomponent polymeric systems, mechanical mixtures consisting of amorphous and crystalline components (LDPE + sodium catalysed butadiene rubber SKB, and polypropylene and methylstyrene rubber) and block copolymer BSP PBPA consisting of flexible chain amorphous polybutadiene blocks of PB and rigid chain crystalline blocks of PA, were chosen. Techniques for the diagnostics and prediction of the properties of polymers are discussed with particular reference to the use of relaxation spectrometry. Physical and chemical modification methods are described, including isotactic compression and heat treatment. An equation is presented which is claimed to make possible the establishment of the functional relationship between the structural and physical characteristics of the polymers subjected to quenching or annealing, and the parameters of the heat treatment schedule. 26 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.16-22)
Title: CONTROL OF THE PROCESSING CHARACTERISTICS OF EPOXY BINDERS FOR GLASS FIBRE REINFORCED PLASTICS
Page Range: T/38-41
Author(s): Usichenko M V; Osipchik V S; Lebedeva E D
File size: 73K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
Two-layer pipes are commonly used in pipelines used for the pumping of aggressive media under different climatic conditions. Plastic pipes of a two-layer construction are used, in which the inner PE layer ensures air tightness and corrosion resistance, and the outer layer of GRP provides the necessary strength and rigidity. However, such a construction consisting of dissimilar materials differing in elastic and thermophysical characteristics, combined with harsh service conditions leads to the emergence of residual stresses. This article examines the need to control the properties of both elements of the pipe and to investigate the nature of interaction at their interface. Particular attention is given to controlling the properties of the epoxy matrix for the production of the glass fibre reinforced plastic shell, and to estimating the residual stresses of the PE-epoxy glass fibre reinforced plastic boundary. The properties of the epoxy-bisphenol A resin were controlled by using effective curing systems and by modifying it with compounds of different natures. New curing systems based on amine and anhydride are proposed. 10 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.23-5)
Title: CALORIMETRIC STUDY OF BLENDS BASED ON POLYVINYL ALCOHOL AND POLYHYDROXYBUTYRATE
Page Range: T/42-44
Author(s): Ol'khov A A; Iordanskii A L; Fel'dshtein M M
File size: 55K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
A calorimetric study is described of blends based on polyhydroxybutyrate (PHB) and polyvinyl alcohol (PVA). The polymers were mixed in PVA/PHB ratios (wt%) of 90:10, 80:20, 70:30, and 50:50. Films were produced from the blends by extrusion of the melt through a plane slit head using a single-screw extruder. Calorimetric studies of the films were carried out using a differential scanning calorimeter. It was seen that films based on PVA were characterised by the presence of two types of crystal structure and one glass transition. In composites based on PVA and PHB the same picture is observed, but the melting peak of the crystalline phase of PHB is superimposed on the high-temperature peak of melting of the PVA. It was concluded that the components of the blends were partially compatible, indicated by an increase in the Tg and a reduction in the specific heat of the PVA phase. Other conclusions reached were that the degree of crystallinity of the PVA falls considerably with an increase in the PHB content of the blend, and that the parameters of the crystallites in the mixed polymers hardly change as a function of the composition of the composites. 10 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.25-6)
Title: ADHESIVE COMPOSITIONS FOR THE BONDING OF POLYMER AND SILICATE CONCRETES
Page Range: T/45-48
Author(s): Cherkezova R T; Radenkov F D; Topliiska A P; Milosheva B D; Radenkov M F
File size: 67K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
It is known that unsaturated polyester resin can be modified by alkaline agents, and is capable of forming, with water, a stable emulsion that subsequently can be cured with peroxides. The unsaturated polyester resin modified in this way can be used to create polyester-silicate concretes and adhesive compositions with high adhesion to cement concrete. This article describes the production of composites in which the unsaturated polyester resin is modified directly with a water-cement slurry. It also examines the effect of doses of surfactants on the properties of polyester concretes and the strength of their bonds with silicate concrete, including in the moist state. 7 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.27-8)
Title: BIODEGRADABLE COMPOSITES BASED ON STARCH
Page Range: T/49-53
Author(s): Sherieva M L; Shustov G B; Shetov R A
File size: 84K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
Work is described which was carried out with the aim of producing a number of biodegradable composites based on starch and/or polyolefins. The research involved the production of a composite consisting chiefly of starch (potato starch) that could be processed by pressing, and then to develop procedures for producing composites consisting of PE and starch, both potato and corn starches. Results of the research confirmed that it was possible to produce biodegradable polymers based on polyolefins. The influence of the starch content is discussed, and also the effect of extrusion on the properties of the composite. 6 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.29-31)
Title: SWELLING RATE AND DURABILITY OF CHIPBOARD IN WATER
Page Range: T/54-56
Author(s): Kiseleva O A; Yartsev V P
File size: 77K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
A study is reported of the swelling processes and durability of chipboard after exposure to a liquid medium. Tests of chipboards of different densities were carried out in fresh and salt water at constant temperatures. The results obtained were used to plot kinetic curves in 'swelling-holding time in water' coordinates which have an exponential nature. At the initial stage, the chipboard swelled more in the fresh water. However, with time, the difference in the degree of swelling in salt and fresh water decreased, especially at elevated temperatures. The experimental results obtained were processed by graph analytical differentiation. A study of the durability (time to failure) under load was also conducted after cyclic exposure to water. It can be seen that exposure to water led to a change in the values of all the constants. Two constants (the activation energy and the pre-exponent) are shown to decrease considerably while the structural force factor increases. Such behaviour of the constants is reported to explain the reduction in durability of the material. The data obtained makes it possible to calculate the swelling rate of chipboard in a wide temperature range, and to predict the durability in a wide range of stresses and temperatures before and after exposure to water. 5 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.31-2)
Title: SYNTHESIS AND PROPERTIES OF COLOURED GRADIENT-MODULUS POLYMERIC MATERIALS
Page Range: T/57-64
Author(s): Luchkina L V; Askadskii A A; Konstantinov K V; Bychko K A; Goleneva L M
File size: 112K
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Issue Year: ipsat
Volume: 32
Issue No: No. 6
Abstract
This work illustrates the possibility of producing coloured gradient-modulus polymeric materials by the block pouring method, the elastic modulus of which changes smoothly within the same specimen. The change in the elastic modulus values is controlled by the composition of the crosslinked polymer, while a slight increase in its values can be achieved by using some of the dyes discussed in the article, without increasing the TDI content. A fat-soluble blue dye is presented as both a polycyclotrimerisation catalyst and a dye. 18 refs. (Article translated from Plasticheskie Massy, No.10, 2004, p.39-44)