Back SearchTitle: USE OF KETONE PEROXIDE IN THE CROSSLINKING OF UNSATURATED POLYESTER RESINS
Page Range: T/1-4
Author(s): Minotti L
File size: 50K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
The preparation of an unsaturated polyester product consists of two separate stages covering the processing of the product (gelling) and the total crosslinking (curing). The choice of the right peroxide can modify the relation of the length of cure and gel times, and as such, by correct choice of the polymerisation system, the gelling and curing time can be modified within certain limits to assist the production process. This article describes the theory of polymerisation in order for uses to accurately modify the polymerisation process on the basis of the use of ketone peroxide for the crosslinking of unsaturated polyester resins. (Article translated from Muanyag es Gumi, No. 10, 2003, p.349-52).
Title: PREDICTING THE THERMOPHYSICAL PROPERTIES OF POLYMER COMPOSITES USING MODEL REPRESENTATIONS
Page Range: T/5-12
Author(s): Baranovskii V M; Temnikova S V; Cherenkov A V; Zeleneva T P; Zelenev Y V
File size: 91K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
In order to describe the processes of heat transfer in polymer composites, it is necessary to investigate the dependence of the effective thermal conductivity of the filled polymer on the geometry, orientation, physicochemical features of interaction, thermophysical parameters, and concentration and distribution of the components of the composite. The use of various models of the theoretical investigation of the thermophysical properties of polymer composites are examined, including the use of computer modelling and the use of renormalisation group methods. A model is proposed which takes into account the presence of pores and a boundary layer around the filler particles, and is claimed to be in good agreement with experimental data on the thermal conductivity of a composite based on Pentaplast (polyether). 12 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.13-8).
Title: STUDY OF THE HEAT RESISTANCE AND MODIFYING CAPACITY OF FUNCTIONALLY SUBSTITUTED COMPOUNDS OF THE ACETYLENE SERIES
Page Range: T/13-16
Author(s): Veliev M G; Chalabieva A Z; Ishchenko N Y; Akperova E G
File size: 45K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
In order to overcome the shortcomings of epoxy resins with reference to thermal stability and resistance, an investigation was carried out to develop chemical additives as modifiers for epoxy resins. This work focuses on establishing the heat stability of functionally substituted compounds of the acetylene series, synthesised by the authors, and using them as modifiers for composites based on industrial epoxy resin ED-20. Data on the heat stability of the acetylene series compounds are given. It can be seen that the heat stability of the compounds depends on their structure and on the nature of the functionalised groups. The heat resistance of the epoxy compounds was determined by thermogravimetric analysis, and the optimum amount of modifier was calculated from the Tg curve and estimated for the activation energy of breakdown of the epoxy compound with a prescribed quantity of modifier. Results of these tests indicated that the use of functionally substituted allylacetylene compounds as modifiers promotes an increase in the heat stability of an epoxy composite based on ED-20. 9 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.19-20).
Title: IMPROVING THE WEATHER RESISTANCE AND MECHANICAL STRENGTH OF POLYMERIC COMPONENTS AND COATINGS
Page Range: T/17-18
Author(s): Mukhamedgaliev B A
File size: 35K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
The need to develop protective coatings for use on metal farm machinery is addressed, with reference to the environmental conditions in Uzbekistan, where agricultural machinery is characterised by intense utilisation for a short period of time, followed by prolonged storage. The protective properties of epoxy coatings are studied with reference to the curing rate, the water and chemical resistance, adhesive strength, and the heat and flame resistance as a function of the chemical composition, the conditions of formation, and the service conditions. The investigations were carried out on composites based on modified ED-20 epoxy resins with various curing agents and modifiers. Results of accelerated laboratory tests of coatings showed that the polymer modifier FSP No.2 (based on metacryloyl chloride and triphenyl phosphite) showed superior protective properties. 3 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.21).
Title: STRUCTURAL DISSIPATION CONCEPT IN THE CREATION OF NEW THERMOSETTING PLASTICS WITH SPECIAL PROPERTIES
Page Range: T/19-20
Author(s): Kryzhanovskii V K
File size: 25K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
A review is presented of research into the creation of new thermosetting plastics with special properties developed in the Department of Chemical Technology of Plastics of the St. Petersburg State Technical University. In addition to the use of traditional methods for chemical modification, the achievement of high dominant properties has become possible on the basis of the new structural dissipation concept. The research has shown that the mechanism of dissipation by the polymer body of external energy, has a pronounced structural relaxation nature. The ability of the polymer to dissipate external energy is determined by the ability of the kinetic fragments of the molecule, or intercrosslink sections of the three-dimensional networks, to perform conformational rearrangements. The resonance of the frequencies of natural oscillations of kinetic fragments with the frequency of the external field is accompanied with intense absorption of external energy with retention of the chemical and physical structure of the polymer. It is therefor possible to construct the physical and chemical structure of the polymer as a set of discrete kinetic fragments with individual frequency amplitude parameters and varying the quantitative ratio of fragments within the three-dimensional network of the polymer, it is possible, on the basis of the limited range of high molecular weight products, to create a wide range of polymeric binders for composites, each of which is noted for its individual dominant characteristic. Further research direction will be an investigation of processes in nanostructural regions of heterophase composites. (Article translated from Plasticheskie Massy, No. 3, 2004, p.28-9).
Title: INVERSION FEATURES OF THE HIGH-ELASTIC DEFORMABILITY OF EPOXY POLYMERS
Page Range: T/21-24
Author(s): Panimatchenko A D; Nikitenko E A; Kryzhanovskii V K
File size: 62K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
The heating of epoxy polymers to above their Tg, converts them into the high-elastic (rubbery) state, exhibiting properties which can be described by the kinetic theory of high elasticity. In accordance with this theory, high-elastic strain (HES) is reversible and depends numerically on the topological structure of the three-dimensional network of the polymer, its chemical structure and the external conditions of the process. In connection with this, an investigation was made of the effect of the density of the three-dimensional network of thermosetting polymers on the HES under isothermal conditions, and also the effect of compressive stress on the HES under isothermal conditions. The process of HES inversion as a function of the physicochemical features of the materials was also investigated. 4 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.29-31).
Title: EPOXY ONE-PACK COMPOSITES AND PLASTIC FOAMS BASED ON THEM (A REVIEW)
Page Range: T/25-31
Author(s): Dvorko I M
File size: 63K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
Epoxy one-pack composites for plastic foams are claimed to be promising materials for the production of high-strength composite and constructional articles in various industrial sectors. This article provides a review of materials, production methods, composition of composites and properties of foam materials. 35 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.36-9).
Title: PLASTIC FOAMS BASED ON NOVOLAC PHENOL-FORMALDEHYDE COMPOSITES MODIFIED WITH OLIGOESTERS
Page Range: T/32-35
Author(s): Dvorko I M; Mokhov M V; Shchemeleva L V
File size: 56K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
Phenol-formaldehyde plastic foams based on novolac oligomers are used as structural materials for articles operating under comparatively harsh service conditions. To improve their service properties, different oligomeric products that interact with the polymer matrix are used as modifying components. This work is devoted to a study of the modification of powder composites for plastic foams with saturated oligoesters synthesised on the basis of ethylene glycol and phthalic anhydride, and also industrially produced oligoester P-R1, a solid product with a softening point of 68-85 degrees C. Results of testing the physicomechanical properties of specimens of plastic foams indicate that the modification of foaming novolac composites with saturated oligoesters is seen as a promising means of increasing the physicomechanical properties of foam materials of structural designation. 8 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.40-1).
Title: ASPECTS OF ENERGY-SAVING TECHNOLOGY FOR PRODUCING ANTIFOGGING COATINGS FOR LIGHT-TRANSMITTING MATERIALS
Page Range: T/36-40
Author(s): Shul'gina E S; Nechaeva E S; Golenishcheva S A
File size: 36K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
The production technology of antifogging light-transmitting materials using protective coatings is discussed, and various methods and techniques are described. These include modifying the surface layer of the material to render it hydrophilic or to make the surface material hydrophobic. With reference to the technologies for the protection of optical materials against fogging, preference is given to the method of applying special coatings. Details are given the various methods for the protective coatings, and their short-comings are examined. The article concludes by recognising the urgent need for the further development of techniques and materials to protect transparent articles against fogging. 62 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.42-4).
Title: PRODUCTION AND PROPERTIES OF ANTIFOGGING ORGANIC GLASSES
Page Range: T/41-43
Author(s): Shul'gina E S; Golenishcheva S A; Nechaeva E S; Sivtsov E V
File size: 46K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
The use is examined of polymeric optical materials in place of inorganic glasses as fogging resistant optical materials. The advantages of using polymeric optical materials are their relatively low cost, low density, and high impact strength, and the possibility of the mass production of articles of complex profile by available production methods. The main optical polymers are produced from PMMA, polycarbonate and polystyrene (PS), SAN and polyethylene glycol bisallyl carbonate (PDEGBAC). The improvement in the surface properties of specimens of glasses of PMMA, PS and PDEGBAC is the subject of this paper, and focuses on the development of a fine chemical technology for the production of multilayer, high-adhesion, moisture-retentive, hard coatings, that together with the originally light-transmitting base, form a unified pseudomonolithic material with constant high light transmission which is stable under extreme service conditions. 4 Refs. (Article translated from Plasticheskie Massy, No. 3, 2004, p.45-6).
Title: STRUCTURE AND PROPERTIES OF THE SURFACE LAYER OF COMPONENTS OF GELLED ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE
Page Range: T/44-47
Author(s): Tsvetkova E A
File size: 132K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
UHMWPE was used in the friction pairs of joint endoprostheses, and a study was made of its modification in order to improve its structure and properties The modification consisted of the formation of a microporous transition layer based on UHMWPE gels and process liquids combined with UHMWPE on the friction surface. This work investigates the microporous surface of the UHMWPE components by means of microscopy in reflected and transmitted polarised light and by electron microscopy. Results indicated that polymer films and coatings treated with a corona discharge were wetted better by water than the initial specimens. Improvement in the wettability was due to an increase in the surface energy at the polymer/air boundary, brought about by electric polarisation. The work demonstrated that the use of corona discharge treatment on microporous specimens lowered their water repellency and could be used as an alternative to high frequency plasma discharge treatment. 14 Refs. (Article translated from Plasticheskie Massy, No. 4, 2004,p.16-8).
Title: PHYSICOMECHANICAL PROPERTIES OF POLYBUTYLENE TEREPHTHALATE MODIFIED WITH POLYAZOMETHINE
Page Range: T/48-50
Author(s): Borukaev T A; Mashukova B S; Mashukov N I; Tlenkopachev M A; Mikitaev A K
File size: 70K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
The modification of polybutylene terephthalate with polymeric additives in order to improve mechanical properties, in particular impact strength, and to reduce thermal stresses is discussed. In this work, an examination is made of the results of physicomechanical investigations of PBT modified with polyazomethines of differing chemical structures. Tests conducted included impact testing, analysis of the fracture surfaces and dielectric investigations. It was concluded that the introduction of small additions of polyazomethine (PAM) into PETP had a modifying effect on the main physicomechanical properties of the initial polymer, and that a change in the main physicochemical properties of PETP as a result of the plasticising effect of PAM has been found. The results obtained are claimed to make it possible to create materials with a combination of improved deformation and strength characteristics. 8 Refs. (Article translated from Plasticheskie Massy, No. 4, 2004,p.18-9).
Title: POLYMERS USED FOR BONE RECONSTRUCTION - EVALUATION OF CHOSEN POLYMERIC MATERIALS FOR IN VITRO CULTURE OF OSTEOBLASTS
Page Range: T/51-59
Author(s): Fabianowski W; Polak B; Lewandowska-Szumiel M
File size: 112K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
A review is presented of polymers which can be used in bone reconstruction for the in vitro culture of osteoblasts. The necessary properties of such materials in order to ensure their successful application, are examined. Such properties include biocompatibility, mechanical strength, resorbability, and surface properties capable of modification. Types of polymeric materials discussed include aliphatic polyesters, natural polymers, dextran hydrogels, polydioxanone, polyamino acids and pseudo-polyamino acids, polyanhydrides, polyorthoesters and polyurethanes. Methods by which to modify the surface of polymeric bone implants by the use of bioactive substances are described. A method is proposed which makes it possible to evaluate the quality of a surface with regard to its capacity for adhesion of bone tissues. This allows for the characterisation of the substrate for further investigations as supports for bone cells. At the present stage of investigations, it is claimed that the most promising are hydrophilic thin layers obtained from dextran with the addition of polyacrylic acid and calcium salt. 39 Refs. (Article translated from Polimery, No. 7-8, 2004, p.522-9).
Title: COMPOSITES OF POLYPROPYLENE WITH CELLULOSE FIBRES. 1. INFLUENCE OF CONDITIONS OF EXTRUSION AND INJECTION PROCESSES ON THE STRUCTURE OF THE POLYPROPYLENE MATRIX
Page Range: T/60-65
Author(s): Garbarczyk J; Borysiak S
File size: 75K
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Issue Year: ipsat
Volume: 31
Issue No: No. 11
Abstract
This article examines the processing of cellulose fibre reinforced polypropylene. It aims to verify on the macro-scale, the results of model studies obtained for composites of isotactic PP and flax fibres. In particular, the study focuses on determining the effect of the fibre content and the processing conditions, particularly the temperature of the extruder head and injection mould, on the supermolecular structure of the polypropylene matrix. Details are given of the chemical modification of the fibres with acetic acid anhydride. 30 Refs. (Article translated from Polimery, No. 7-8, 2004, p.541-6).