Back SearchTitle: REVIEW: PRODUCT INNOVATION WITH OLEFIN POLYMERISATION CATALYSTS
Page Range: T/1-8
Author(s): Kashiwa N; Kaneko H; Kojoh S
File size: 62K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
A review is presented of developments in olefin polymerisation catalysts, starting with the discovery of Ziegler-Natta catalysts in 1953. Olefin polymerisation catalysts date from the discovery of the polymerisation action of organic zirconium complexes and first focused on heterogeneous catalysts comprising inorganic compounds in the field of general-purpose resins such as PE and PP. The review charts the progress from the discovery of metallocene, homogeneous catalysts which provide single-site polymerisation at high activity, which are used to improve the quality of existing polymers and provide the potential for the creation of novel polymers. It is stated that the homogeneity concept has been a substantial obstacle in application to existing production processes, and that new developments will incorporate the merits of heterogeneous catalysts (high thermal stability and good morphological control), with those of homogeneous catalysts (single site activity with unique polymerisation capabilities). Once this is established, the authors claim that drop-in catalyst technology applicable to existing production processes will be available as a novel heterogeneous catalyst system making maximum use of the special features of homogeneous catalysts. 16 refs. Article translated from Nippon Gomu Kyokaishi, Vol. 75 (2002), pp.390-6).
Title: LOW MODULUS-HIGH DAMPING RUBBER FOR VIBRATION CONTROL DEVICES - DEVELOPMENT AND OUTLOOK
Page Range: T/9-14
Author(s): Minowa M
File size: 147K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
This article considers the trade-off between the overall properties required for high damping polymeric viscoelastic materials used for vibration control. In addition to high damping performance, viscoelastic polymers of this kind require elastic modulus, strength, durability and other properties which are suitably adjusted at the material level. A reduction in the elasticity of the material enables the durability of the vibration control device to be extended, and allows application to lightweight structures. A technique is discussed which enables the damping performance of polymeric viscoelastic materials to be increased by using the glass transition region of the polymer. Whilst imparting a very high damping performance (loss tangent, loss modulus) to the material, it also has the effect of greatly restricting the service environment, since the transition region generally occupies a narrow temperature range over which there is a large change in elastic modulus. This work investigates ways of widening the temperature range of the transition region and increasing the working temperature range. Formulations investigated include isoprene rubber as the base polymer, carbon black and other fillers. An evaluation is presented of the mechanical properties of test pieces and model rubber laminate bearings. 7 refs. (Article translated from Nippon Gomu Kyokaishi, Vol. 76 (2003), No.3, pp.101-4).
Title: PREDICTING THE STRENGTH PROPERTIES OF GLASS FABRIC REINFORCED COMPOSITES FROM THEIR INTERFACIAL CHARACTERISTICS
Page Range: T/15-17
Author(s): Anisimov Y N; Khromov V I
File size: 44K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
An investigation is reported into strength characteristics of glass fabric reinforced polymer composites with special consideration of the interfacial characteristics at the polymer matrix-glass fabric interface. Consideration is also given to the possibility of predicting the adhesion and impact strength of these composites as a function of the type of polymer resin. The polymer resins used were epoxy-bisphenol, epoxy-resorcinol, epoxy-silicon and epoxy-urethane, copolymers of unsaturated oligoester resin polyethylene glycol maleate phthalate with monomers of styrene and methyl methacrylate, and also with the oligoester acrylates triethylene glycol methacrylate phthalate and ditriethyleneglycol dimethacrylate phthalate. The filled composites based on these copolymers were cured at 20 degrees C using an effective redox initiating system of methyl ethyl ketone peroxide and cobalt diacetylacetonate. Experimental data on the dependence of static flexural strength of the studied composites on the type of polymer matrix are given. The possibility of predicting by the use of derived equations, the strength characteristics of glass fabric reinforced composites by consideration of the interfacial characteristics at the interface between the polymer resin and the reinforcing fibre is demonstrated. 8 refs. (Article translated from Plasticheskie Massy, No.11, 2002, pp.12).
Title: PREDICTING THE CHANGE IN PHYSICAL PROPERTIES OF POLYMERIC MATERIALS WITH DIFFERENT METHODS OF MODIFICATION
Page Range: T/18-23
Author(s): Zelenev V; Khromov V I
File size: 76K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
A study is reported in which structural changes in polymers are brought about by thermomagnetic treatment, i.e. the use of both heat treatment and the action of magnetic fields. It is noted that the action of steady magnetic fields has a considerable influence on the thermophysical and mechanical properties of amorphous and crystalline polymers, due to the orientation of the elements of their supramolecular structure. The study showed that during heat treatment of different classes of polymers (non-crystalline and crystalline, non-polar and polar)the fundamental 'fork rule' which is valid for all solids, applies. 8 refs. (Article translated from Plasticheskie Massy, No. 11, 2002, pp.13)
Title: EFFECT OF STRESS CONCENTRATOR ON THE STRENGTH AND DURABILITY OF WOOD FILLED PLASTICS
Page Range: T/24-27
Author(s): Yartsev V P; Kiseleva O A
File size: 61K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
Fibreboard and chipboard materials of different densities were tested by transverse bending under conditions of a given constant rate of loading and under given constant loads and temperatures to determine the influence of stress concentrators. The commonest forms of stress concentrators are holes, since these materials are often secured by nails or screws. Equations are given which make it possible to calculate the durability and long-term strength of wood boards under predetermined constant service parameters: stress, temperature and time of loading. It is concluded that the creation of a stress concentrator in wood boards leads to an increase in the real short-term strength of the material. An increase in the homogeneity and orientation of the filler in wooden boards leads to a change in the character of the dependencies, reflecting the process of breakdown under the prolonged action of constant loads and temperatures. 9 refs. (Article translated from Plasticheskie Massy, No. 11, 2002, pp.18).
Title: HYDROLYTIC STABILITY OF POLYMERIC COMPOSITIONS CURED UNDER VARIOUS CONDITIONS
Page Range: T/28-30
Author(s): Ligidov M K
File size: 49K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
A method is proposed for the formation of an equilibrium structure of a polymer composition which is resistant to hydrolysis and abrasion. A mixture of PU and polyhydroxyether cured with triisocyanate was proposed as the polymer binder for such as composite. The method consists of curing a system using stepwise non-isothermal conditions so that the curing process takes place under conditions in which the cure temperature increases ahead of the rise in Tg of the mixture. Then the process takes place in a system which is in a high elastic state, where the molecular (segmental) mobility is high and the process is rapid, and the resulting chemical three-dimensional structure is more equilibrium and resistant to hydrolysis and abrasion. 4 refs.(Article translated from Plasticheskie Massy, No. 11, 2002, pp.20).
Title: EVALUATION AND PREDICTION OF CLIMATIC RESISTANCE OF COMPOSITES OF FLUOROPLASTIC WITH QUARTZ FABRIC
Page Range: T/31-34
Author(s): Rodionov N N
File size: 44K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
An investigation is reported into the ageing characteristics of a composition of a fluoropolymer binder, characterised by high weathering resistance, in combination with a reinforcing quartz fabric, the fibres of which have the highest mechanical strength. These characteristics provide a basis for predicting prolonged retention of the properties of the composite under service conditions. The composite is characterised by improved electrical properties and non-flammability. Parallel tests in artificial and natural conditions are performed and the results are correlated to shorten the test time while predicting the changes in properties. To assess the state of the composite, the following properties were selected: the dielectric permittivity, dielectric loss tangent, tensile strength, and breakdown strength with alternating voltages. For observation of the structure of the composite, the density of the material, the porosity and water absorption was monitored, the external appearance being assessed visually. It was concluded that the composite studied is durable and that the decrease in mechanical strength can be reliably predicted by the use of the empirical relationships obtained. 4 refs. (Article translated from Plasticheskie Massy, No. 11, 2002,pp.22).
Title: THERMOMECHANICAL GRAFTING OF NITROXYL RADICALS TO LOW-DENSITY POLYETHYLENE
Page Range: T/35-38
Author(s): Guseva S G; Tyurikov V A; Ushakova O B; Potapov E E
File size: 59K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
The use of stable radicals for the chemical modification of polymers is discussed with reference to the use of nitroxyl radicals. The introduction of nitroxyl radicals into the structure of polymer macromolecules allows for their physical, mechanical, chemical and service properties to be considerably modified. The main characteristic of nitroxyl radicals which distinguishes them from other stable organic radicals is the preferential localisation of an unpaired electron at the NO unit, and the reduction of its energy level.. This paper presents results of studies of the preparation of polyethylene containing nitroxyl radicals immobilised on the polymer chains. The generation of active radical centres on the polymer chain was achieved by thermomechanical action on the polyethylene. Nitrons interacting with these centres are converted into stable nitroxyl radicals. 7 refs. (Article translated from Plasticheskie Massy, No. 11, 2002, pp.32)
Title: LAWS GOVERNING THREE-DIMENSIONAL STRUCTURE IN MIXTURES OF EPOXY-NOVOLAC AND FORMALDEHDYE RESINS
Page Range: T/39-41
Author(s): Ligidov M K; Tkhakakhov R B; Mikitaev A K
File size: 66K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
The value of materials based on epoxy-novolac resins is described in terms of high adhesion to metals, low shrinkage during curing, chemical resistance and high strength, all of which make them suitable candidates for use as binders in the working layers of magnetic recording media. It is this application that prompts the need to establish the laws governing the formation of the three-dimensional structure in order to select the optimum temperature and time conditions for the curing of epoxy-novolac resins. Investigations were carried out by means of IR spectroscopy, and by use of dielectric relaxation, making it possible to obtain information on the density and homogeneity of the three-dimensional chemical network. The behaviour of epoxy-novolac resins cured under different temperature and time conditions was studied by means of differential thermogravimetry and differential thermal analysis with the simultaneous recording of weight losses of the specimen. It is shown that the introduction into the mixture of small amounts of polyhydroxyether, accelerates the curing process considerably under the same temperature and time conditions, acting as another curing agent for epoxy-novolac resin, and promoting structure formation of the interpenetrating network type. 8 refs. (Article translated from Plasticheskie Massy, No. 12, 2002, pp.15-6).
Title: PHYSICO-MECHANICAL AND DIELECTRIC PROPERTIES OF EPOXY-TITANOXANE ACRYLATE POLYMERS
Page Range: T/42-46
Author(s): Dul'tseva L D; Suvorov A L; Ostanina N Y; Shatrova Y V; Suvorova A I
File size: 77K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
An investigation is reported of the dependence of the properties of epoxy-titanoxane acrylate polymers on the formulation of the composite and the structure of the curing agent in terms of the degree of polycondensation, the presence and chemical nature of the acyloxy groups, the ratio of the number of these groups and titanium atoms in a molecule. The investigation was carried out on epoxy composites and polymers containing as curing agents, polybutoxytitanoxanes,, (PBTBPs), or polybutoxytitanoxane acrylates. Tests were carried out to assess the activity of the curing agents, the tensile strength of the cured polymers, the glass transition temperature, the dielectric characteristics, and the structure of the cured polymers. Results indicate the optimum resin/curing agent ratios to ensure the formation of a denser network. 7 refs. (Article translated from Plasticheskie Massy, No. 12, 2002, pp.17-9).
Title: BLENDS BASED ON POLYVINYL ALCOHOL AND POLYHYDROXYBUTYRATE
Page Range: T/47-50
Author(s): Ol'khov A A; Iordanskii A L; Shatalova O V
File size: 70K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
This work reports on the use of blending techniques to modify the properties of materials based on polyvinyl alcohol (PVA). The structural features and properties were investigated of composites based on PVA and polyhydroxybutyrate by different methods of structural analysis. The composite blend was obtained by melt extrusion. The structure of the films was studied by differential scanning calorimetry, the tensile properties of the film specimens were also tested, and steam permeability was studied using special membrane cells by measuring the weight loss by the cell.. Results of X-ray diffraction analysis indicate that each of the components of the blend is capable of forming an independent crystalline phase. Details are given of optimum blend ratios. 15 refs. (Article translated from Plasticheskie Massy, No. 12, 2002, pp.20-2).
Title: KINETICS OF AGEING OF BASALT AND CERTAIN GLASS FIBRES IN AN ALKALINE MEDIUM
Page Range: T/51-55
Author(s): Dalinkevich A A; Gumargilieva K Z; Sukhanov A V; Aseev A V; Zharov A I
File size: 72K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
A comparative kinetic analysis is presented of the alkali resistance of basalt fibres and two types of glass fibre (E- and zirconium glass). The kinetic laws governing reduction in the breaking load during the ageing of basalt and glass roving in an alkaline medium are obtained and the parameters entering them are determined. Derived equations are shown to be in agreement with experiment and take into account the reduction in the breaking load of basalt and glass fibres owing to the occurrence of adsorption processes and surface chemical dissolution of some of the components of the basalt or glass in an aqueous solution of alkali. The laws obtained can be used to predict a reduction in the strength of roving and other basalt and glass fibre materials under the prolonged action of aggressive alkaline media. 14 refs. (Article translated from Plasticheskie Massy, No.12, 2002, pp.23-6).
Title: EVALUATION OF THE PHASE STATE OF THE STRUCTURE OF POLYMER COMPOSITES
Page Range: T/56-57
Author(s): Bobryshev A N; Zharin D E; Gumerov A F; Yurasov S Y
File size: 74K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
A model of finely filled polymer composites is studied to determine and predict the quality of strength in a loaded composite. The interrelationship between the reinforcing particles and polymeric matrix materials is examined, which demonstrates that filling is connected, not only with the introduction of a rigid component into the composite, which in itself affects the final properties of the material, but also with the emergence in the composite system of an internal field causing ordering of the structure of the matrix in the boundary layer of the attracting surface potential of the particles. Optimum filler contents are derived with respect to dependence of strength of composites on volume content of filler, and the proportional amount of film phase to the volume fraction of the filler for the formation of a rigid structural lattice is recognised in order to provide effective strengthening. 1 ref. (Article translated from Plasticheskie Massy, No.12, 2002, pp.26-8).
Title: EFFECT OF SURFACE TREATMENT OF REINFORCING GLASS FIBRE ON THE PROPERTIES OF GLASS FIBRE REINFORCED PLASTICS BASED ON A THERMOPLASTIC MATRIX. II. A NON-POLAR POLYETHYLENE MATRIX
Page Range: T/58-63
Author(s): Smirnov Y N; Vlasova N N; Rudakov V M; Ol'khov Y A; Barelko V V; Sivyi B P; Borisov Y A; Rakitskii S S; Danilov K E
File size: 71K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
A study is reported which aims to investigate the effect of different forms of surface treatment of reinforcing glass fabric, and also methods of combining it with the matrix, on the physicomechanical properties of GFRPs based on a non-polar polyethylene matrix. To apply the PE matrix, a method of polymerisation filling was used, and in some cases, the prepregs were additionally resurfaced with a HDPE film, which was used to improve the follow of the initial PE matrix. The use of the method of polymerisation filling, combined with acid etching of the glass fibre, is shown to make it possible to increase the constructional rigidity and cross-breaking strength of GFRPs, with a certain reduction in water absorption. 27 refs. (Article translated from Plasticheskie Massy, No.12, 2002, pp.28-32).
Title: INVESTIGATION OF THE STRUCTURAL FEATURES AND PROPERTIES OF POLYMER BLENDS USING DIFFERENTIAL KINETIC EQUATIONS
Page Range: T/64-67
Author(s): Shogenov V K; Tkhakakhov R B; Ozov K K; Karamurzov B S
File size: 55K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
In this work, an investigation is made of the kinetic equations and their diffusion approximations and the process of interdiffusion of statistical segments during the mixing of two polymers. The approach proposed makes it possible to calculate the thickness of the transition layer and thereby model the morphology of polymer blends. A mathematical model is presented, and on the basis of the equations proposed, an assessment is given of the thickness of the transition (diffusion) layer, which amounts to the order of the size of a statistical segment, making it possible to determine the volume of the diffusion layer in 'polymer-polymer' systems. 8 refs. (Article translated from Plasticheskie Massy, No. 12, 2002, pp.32-5).
Title: THERMO-PHYSICAL PROPERTIES OF POLYMERIC ANTI-FRICTION COATINGS AND THEIR APPLICATION
Page Range: T/68-70
Author(s): Kokhanovskii V A; Mukutadze M A
File size: 60K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
Investigations of the values and nature of the changes in the thermophysical properties of composite coatings as a function of the curing schedules, are shown to make it possible to optimise the curing temperature and pressure, to ensure high quality, durable polymeric anti-friction coatings. The coatings examined are composites based on special fabrics of polymer fibres and polymeric matrix material, which acts as an adhesive, fixing the coating on the substrate. The anti-friction component of the composite comprises Polifen fluoroplastic fibres, and the matrix material is phenol formaldehyde binder. The technology for applying the coatings examined includes fixing the prepreg on a substrate at a certain pressure and temperature, which are determined by means of thermal calculations. 2 refs. (Article translated from Plasticheskie Massy, No.12, 2002, pp.44-5).
Title: STUDY OF STRUCTURE FORMATION IN BIODEGRADABLE FILM MATERIALS BASED ON POLYSACCHARIDE SYSTEMS
Page Range: T/71-73
Author(s): Loshadkin D V; Kalugina N A; Peshekhonova A L; Rozantsev E G
File size: 66K
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Issue Year: ipsat
Volume: 30
Issue No: No. 8
Abstract
An investigation was carried out on model films based on methyl cellulose with additions of corn starch or rhamnose, used as biodegradable packaging materials, in order to study the processes of structure formation. This was carried out using polarisation microscopy. To describe the structure by fractal geometry methods, use was made of a special program 'MFRDrom' developed under the supervision of Dr. G.V. Vstovskii. It was assumed to be possible to use a model of cluster-cluster aggregation (CCA process) for a description of the process of structure formation, and using the CCA process, gelation and the formation of combined dispersed systems were modelled. 7 refs. (Article translated from Plasticheskie Massy, No.12, 2002, pp.46-7).