Back SearchTitle: MODIFICATION OF PHENOL-FORMALDEHYDE OLIGOMERS WITH PROPARGYL ETHERS
Page Range: T/1-4
Author(s): Naibova T M; Bilalov Y M; Talybov G M; Karaev S F
File size: 80K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
The modification of phenol-formaldehyde oligomers (PFOs) using propargyl ethers as modifiers, is described. The main physicomechanical properties of the products of the modification of PFOs with 2,5-dimethyl-2,5-bis(2-propynyloxy)-1,4-dioxane, 6-bromo-5-phenyl-4-oxa-1-hexyne, and 1-choro-3-bromo-2-propargyloxypropane, and also the physicomechanical and thermo- and electrophysical properties of materials based on them, are determined by the composition and structure of the modified oligomers. IR spectra of the modified and unmodified oligomers were compared. By structural chemical, physicochemical, and spectral analysis, it was demonstrated that the obtained PFOs modified with propargyl ethers were not mechanical mixtures of phenol, formaldehyde and modifier. The content of hydroxyl and methylol groups was determined and also the degree of curing of unmodified and modified PFOs. A study was also made of the thermooxidative degradation of the modified PFOs under conditions of dynamic thermogravimetry. It was concluded that the modification of PFOs with propargyl ethers promoted acceleration of the polycondensation of phenol and formaldehyde, and in connection with this, the content of residual phenol in the composition of the reaction products of polycondensation decreased by a factor of 3-5. 9 refs. (Article translated from Plasticheskie Massy, No.11, 2004, p.34-5)
Title: OPTIMISATION OF INJECTION MOULDING ON THE BASIS OF THE MECHANICAL AND ECONOMIC PARAMETERS OF THE PROCESS
Page Range: T/5-10
Author(s): Spiridonov P N; Protopopov Y M
File size: 154K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Details are given of a computer software program which has been developed for the optimisation of the injection moulding process with reference to both technical and economic parameters. The program module was developed on the basis of Microsoft Excel and consists of several interconnected large-format tables. On the first, the input of the data necessary for calculations and the read-out of the results of calculations are carried out. The second and third tables are designed for technical and economic calculations respectively. Additional tables are used to calculate the payback period, the return on investments, and the total time required for the production of a certain volume of articles. The calculations are carried out in two stages: at the first stage, the technical parameters of the injection moulding machine for the production of the prescribed articles in a prescribed volume are calculated, and a machine of the necessary size is selected. At the second stage, on the basis of economic calculations, the optimum number of cavities in the injection mould is determined. The presented method of optimisation makes it possible to estimate different variants and to take account of different technical and economic factors in determining the optimum number of mould cavities, and is a useful auxiliary tool in decision making, since certain technical and design complexities in the development of injection moulds cannot be taken into account. 7 refs. (Article translated from Plasticheskie Massy, No.11, 2004, p.36-9)
Title: MODEL OF THE DEFORMATION AND STRENGTH CHARACTERISTICS OF CHLORINE-CONTAINING POLYESTERS
Page Range: T/11-12
Author(s): Kekharsaeva E R; Gachaev A A; Aleroev B S
File size: 52K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
A model of the deformation and strength characteristics of chlorine-containing polyesters is refined with reference to earlier works. The analysis conducted in an earlier monograph indicated that, if the stress and the strain within a finite time are unable to refer to infinity, then the mechanical properties of viscoelastic materials, and in particular chlorine-containing polyesters, can be described by the rheological equation of state, and that with reference to a model constructed of polymers in the 'large' strain section, based on fractional-order derivatives, it is possible to approximate the given equation with an integral curve. 5 refs. (Article translated from Plasticheskie Massy, No.11, 2004, p.39)
Title: THE MODIFICATION OF INDUSTRIAL BITUMENS WITH POLYMER ADDITIVES
Page Range: T/13-15
Author(s): Arzamastsev S V; Chechulin D V; Artemenko S E; Ionov I A; Patronov V P
File size: 63K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
The aim of this research was to develop technology for the production of a polymer bitumen binder (PBB) modified with different additives. The research focussed on the following: to study the possibility of modifying the bitumen binder with different additives, including industrial waste; and to establish the dependence of the characteristics of the polymer bitumen binder on the amount and type of modifier introduced into the bitumen. The additives used were industrial rubbers butadiene-styrene rubber, EPDM, tyre reclaim, and vat residue from polycaproamide production. The results of the research demonstrated that for the modification of bitumen, it was promising to introduce into the bitumen an additive of LDPE and butadiene-styrene rubber, the ratio and amount of which can be varied as a function of the characteristics of the initial bitumen and the required values of the processing properties of the PBB. 3 refs. (Article translated from Plasticheskie Massy, No.11, 2004, p.40-1)
Title: MECHANICAL RELAXATION PROPERTIES OF THERMALLY STABLE POLYMERS AT LOW TEMPERATURES
Page Range: T/16-23
Author(s): Askadskii A A; Migonene Z B
File size: 163K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Polyheteroarylenes are thermally stable, chemically resistant polymers which can be used in specialised areas of engineering. Investigations were carried out into the mechanical relaxation properties of constructional polymers of aromatic structure with heterocycles of different structures in the main chain, (polybenzoxazole, polyoxadiazole, and polyimide) under compression conditions. Their ability to withstand a large number of thermal shock cycles from high to low temperatures was assessed. The specimens had been stored at room temperature for 20 years. The experimental analysis of the stress relaxation and creep of polybenzoxazole, polyoxadiazole and polyimide, showed that, up to a temperature of 103 K under compression conditions, the polymers showed no brittleness, possessed high deformability and exhibited pronounced stress relaxation and creep in a wide stress and strain range. For polybenzoxazole, the presence of a relaxation transition was established, dividing the low-temperature zone into sub-regions with different rates of relaxation processes. The region of mechanical durability was determined, and it was established that time hardly affected the strength properties, the rate and nature of mechanical relaxation processes and the X-ray diffraction characteristics. 18 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.6-12)
Title: EFFECT OF CERTAIN SOLVENT PARAMETERS ON THE STRUCTURE OF POLYHYDROXYBUTYRATE FILMS
Page Range: T/24-26
Author(s): Ol'khov A A; Iordanskii A L; Fel'dshtein M M
File size: 70K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Since most biopolymers of bacterial origin are sensitive to increased temperature, the moulding of them is carried out from solution. Biopolymers used as the matrices for the controlled release of drugs, have the drugs introduced into them chiefly via solution. One of the progressive polymers used in medicine is polyhydroxybutyrate (PHB). This bacterial biopolymer possesses high crystallinity. By changing the degree of crystallinity of the polymer at the stage of formation of films from solution, it is claimed to be possible to control the transport properties in a wide range. The aim of this work, therefore, was to determine the effects of solvents of different polarity on the structure formation of PHB films. With an increase in solvent polarity, there was found to be an increase in the ability of the solvent to interact with the polar groups of PHB. As a result of this interaction, there was an improvement in the crystallites and an increase in density of the amorphous phase of the polymer during formation of the film. With a reduction in the degree of intermolecular interaction in the solvent, there was an increase in the proportion of defective crystalline phase in the PHB films. 10 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.12-3)
Title: KINETICS OF SORPTION OF ORGANIC LIQUIDS BY SEGMENTED POLYURETHANE UREA
Page Range: T/27-29
Author(s): Tereshatov V V; Volkova E R; Denisyuk E Y
File size: 86K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Segmented polyurethane materials are characterised by high oil and petrol resistance, and resistance to a number of solvents. To assess the intensity of transfer of a substance through such a film, it is necessary to know the solubility of the substance in the polyurethane material and the magnitude of its diffusion coefficient. For the analysis of the diffusion kinetics of swelling of polymer networks, in the present work, use was made of a mathematical model describing the non-equilibrium process of swelling of a flat elastomer specimen that occurs under finite strains of the polymer matrix. Results are presented of the kinetics of absorption of a number of liquids by segmented polyether-urethane urea, and an assessment is made of the diffusion coefficient of these liquids in a crosslinked polymer with a three-dimensional network in which there are both chemical and physical crosslinked points resulting from domains of rigid blocks. 6 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.14-5)
Title: PREDICTING THE ELASTIFICATION OF DENSELY CROSSLINKED POLYMERS
Page Range: T/30-34
Author(s): Garipov R M; Sof'ina S Y; Mochalova E N; Deberdeev T R; Efremova A A; Irzhak V I
File size: 119K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
In order to achieve a solution to the problem of brittleness in glassy materials based on densely crosslinked polymers, methods are described to increase impact strength. An effective method is claimed to involve the lowering or reduction of the concentration of the crosslinked points. This approach, leading to a considerable reduction in the glass transition temperature of the cured system, it is claimed, making it possible to achieve a high degree of conversion during low temperature curing. This is due to a reduction in the effect of retardation of the reaction owing to glass transition of the reaction mass. Lowering of the concentration, or a reduction in the functionality of the crosslinked points can be achieved by changing the stoichiometric ratio between the functional groups of the oligomer and curing agent, and/or by using monofunctional compounds as modifiers. This work is devoted to a study of the properties of epoxies modified by two different methods. 13 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.16-8)
Title: THE BREAKDOWN OF PLASTICISED COMPOSITES BASED ON POLYVINYL CHLORIDE
Page Range: T/35-37
Author(s): Tkhakakhov R B; Zhazaeva E M; Begretov M M; Tkhakakhov E R; Zavoda A A
File size: 65K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
In this work, a study was made of the nature of the stress-strain relationship under elongation of dioctyl phthalate (DOP)-plasticised PVC at strain rates of 100 and 200 mm/min. The plasticisation of PVC with DOP was carried out in a rapid mixer with subsequent milling. It was seen that an increase in the proportion of DOP led to a small increase in the strain ratio and to a sharp reduction in the tensile stress. It was established experimentally that on the stress-strain diagrams for plasticised composites based on PVC with minimum strain rates, there appeared abnormalities whose nature depended both on the strain rate and on the plasticiser concentration. The addition of DOP to a PVC-butadiene-acrylonitrile rubber blend promoted an improvement in the compatibility of the components, as reflected by the temperature dependence of the dynamic, mechanical and strength characteristics of the given composites. 14 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.19-20)
Title: MODIFICATION OF PHENOL-FORMALDEHYDE NOVOLAC WITH 1,7-BIS(CARBOXYMETHYLCARBAMOYL)-M-CARBORANE AND ZINC OLIGOSALT
Page Range: T/38-40
Author(s): Bekasova N I; Nechaev A I; Surikova M A; Shitikov V K; Salazhin S N
File size: 65K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
It is known that composites produced in a novolac melt with 10 wt.% additions of zinc oligosalt of m-carboranedicarboxylic acid (Zn-MC) have increased thermal stability and retention of strength characteristics. However, the infusibility and rigid structure of oligosalt Zn-MC makes the production of homogeneous composite materials significantly more difficult, it is stated. It was assumed that the introduction into this oligosalt of methylene fragments would make it more flexible and thereby improve its compatibility with different polymers and increase the strength characteristics of the composites. To test this assumption, 1,7-bis(carboxymethylcarbamoyl)-m-carborane (GK) and its zinc oligosalt (Zn-GK) were synthesised. Novolac composites were obtained with a content of 10 wt.% Zn-GK and GK respectively, and for comparison, novolac composites with 10 wt.% additions of Zn-m-carboranecarboxylic acid (MK) dichloride and MK, in which there were no CH2 or amide fragments. From the results presented in the research, it was concluded that the presence of -CH2 and Zn-GK used for the modification of novolac, raises the heat resistance of the latter through the formation of a crosslinked structure that is heat stable even at 900 degrees C and which retains up to 50% of the initial strength of the specimens. 5 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.35-6).
Title: SYNTHESIS OF EPOXYIMIDES BASED ON 2-SULPHOTEREPHTHALIC ACID IMIDE
Page Range: T/41-42
Author(s): Aslanov T A
File size: 55K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Epoxyimide resin was synthesised on the basis of 2-sulphoterephthalic acid and epichlorohydrin. The composition and structure of the synthesised epoxyimide resin were confirmed by IR spectroscopy and elemental analysis. The curing capacity and heat resistance of epoxyimide composites produced from the synthesised resins was studied. Polyethylenepolyamine (PEPA) was used as the cold curing agent and a curing agent of the anhydride type, methylendic anhydride (MEA) was used as the hot curing agent. For comparison of resins, industrial resin ED-20 was used. Epoxyamide and ED-20 resins were cured by PEPA at 75 degrees C, and on the DTA curve in this region, an intense exopeak of curing was observed. This was connected with presence in the resin of a tertiary nitrogen atom which autocatalyses the curing reaction. Thus, the presence in the structure of the resin of tertiary nitrogen increased the curing rate, but did not lower the temperature. The resin behaved similarly when cured by MEA ,with an exopeak appearing in this case at a temperature of 150 degrees C, while ED-20, in the absence of a curing accelerator, is cured at 180 degrees C over a 20 h period. The heat resistance of the specimens was assessed from the activation energy of decomposition, which was calculated by double logarithm, using a described procedure. The results of the calculation are given. 7 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.38-41).
Title: COMPLEXING OF HYDRAZINE- AND PHENYLHYDRAZINE-MODIFIED POLYACRYLONITRILE FIBRES WITH IODINE
Page Range: T/49-54
Author(s): Ikramova M E; Mukhamediev M G; Musaev U N
File size: 118K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
The possibility of the complexing of iodine with hydrazine-modified, hydroxylamine-modified polyacrylonitrile fibres is referred to with reference to earlier research. It was established that the complexing capacity and stability of the complexes were dependent on the nature of the functional groups n the polymer chain. Taking into account the fact that the introduction of an aromatic fragment into the anion-exchange resin should stabilise polyiodide groups, the possibility of further modification with phenylhydrazine was studied. For this, polyacrylonitrile fibres crosslinked by hydrazine were used s the initial products for subsequent chemical modification. The treatment of hydrazidised fibres with a benzene solution of phenylhydrazine, showed that during the reaction, new functional groups were formed which had an ion-exchange nature. Their ion-exchange properties, however, disappeared under the action of aqueous solutions. Therefore, to introduce phenylhydrazide groups, fibres crosslinked by hydrazine hydrate, in order to from carboxyl groups, were subjected to hydrolysis. The carboxyl-containing fibres were then modified with phenylhydrazine. It was found that over the course of the reaction, the static exchange capacity of the hydrolysed fibre decreased as a result of amidisation of the carboxyl groups. The introduction of phenylhydrazide groups into the composition of anion-exchange polyacrylonitrile fibres is shown to have a considerable effect on the kinetics and thermodynamics of the process of sorption of iodine and its desorption from sorbents. 4 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.41-2)
Title: 3-D AMINOEPOXY POLYMERS BASED ON GLYCIDYL ESTERS OF UNSATURATED ACID
Page Range: T/43-48
Author(s): Ergozhin E E; Bektenov N A; Chopabaeva N N
File size: 66K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Materials based on epoxy and acrylic monomers are the most promising for the synthesis of different types of polymer, ion-exchange resin, and sorbents, it is claimed. The high reactivity of the functional groups of epoxy and acrylic monomers and the stability and resistance of the macromolecules formed on their basis, make it possible to conduct their chemical transformations under moderate conditions. The increased activity of oxirane groups is confirmed by their considerable proneness to curing reactions in the presence of agents of an acidic or basic nature with the formation of three-dimensionally crosslinked or branched polymers possessing ion-exchange and other valuable properties.. This work is concerned with the synthesis and investigation of aminoepoxy ion-exchange resins based on homo- and copolymers of glycidyl methacrylate (PGMA) and methyl methacrylate (GMA-MMA) by means of their chemical modification by curing agents of a basic nature. The investigation made it possible to establish that the three-dimensional aminoepoxy polymers synthesised by the chemical modification of homo- and copolymers of glycidyl methacrylate with polyamines of aromatic and aliphatic nature, possessed a high exchange capacity and increased chemical and heat resistance, thus expanding their application in progressive ion-exchange and sorption technologies. 26 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.38-41)
Title: NANOCOMPOSITE POLYMERIC MATERIALS BASED ON CLAYS MODIFIED WITH AN ORGANIC SUBSTANCE
Page Range: T/55-62
Author(s): Mikitaev A K; Kaladzhyan A A; Lednev O B; Mikitaev M A
File size: 341K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
In this work, an analysis is made of available published data on the development of new materials using nano-size fillers of an inorganic nature. The research discussed demonstrates the possibility of using practically all varieties of polymerisation and polycondensation polymeric materials as the matrix. Organomodification is carried out principally using ionogenic surfactants. It is concluded that a general concept has been formed concerning the investigation methods and the structure of polymer nanocomposite materials, and also the dependence of the main deformation and strength properties on the specific nature of the structure of the nanocomposites. Advantages of modified organoclays over simple clay in terms of dispersibility in the polymer matrix and interaction with the polymer chain are discussed. By introducing organoclay into the polymer matrix, it was possible to improve heat stability and mechanical properties of the polymers. 70 refs. (Article translated from Plasticheskie Massy, No.12, 2004, p.45-50).
Title: VISUALISATION OF SUPERMOLECULAR STRUCTURES IN POLYURETHANE IONOMERS USING ATOMIC FORCE SPECTROSCOPY
Page Range: T/63-69
Author(s): Krol P; Krol B; Skrzpiec K
File size: 498K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
Atomic force microscopy is used to analyse and visualise the surface structure of polyurethane ionomers. Specifically, this article describes use of the technique which allows for the analysis of surface structures formed spontaneously during the formation of films from water-thinnable PU ionomers. The results confirm the complex phase structure resulting from physical interactions between the rigid and flexible segments present in the polyurethane chains. Comparison of the cationomer and anionomer structures of the PU showed that intensive modification could be achieved by the use of cationomer systems in which there are greater structural possibilities for the formation of hydrogen bonds and distribution reactions between segments of different polarity. These interactions led to a marked separation of the hard and soft domains which changes the character of the surface and affects its adhesion to other materials. A proposed more intensive modification of the surface structure of PU via the formation of poly(urethane-acrylic) anionomers is thought to give rise to an increase in the elasticity of the resultant films, and may lead to the development of more effective agents for binding powdered ceramic materials. 21 refs. (Article translated from Polimeri, No.2, 2005, p.123-30)
Title: MODIFIED BENTONITES AS ACTIVE ADSORBENTS OF STYRENE VAPOURS
Page Range: T/70-75
Author(s): Oleksy M; Heneczkowski M
File size: 186K
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Issue Year: ipsat
Volume: 32
Issue No: No. 8
Abstract
The use is examined of modified bentonites as active adsorbents of styrene vapours released as a result of the synthesis and processing of unsaturated polyester resins. This paper examines the effect of the type of substituents on the quaternary nitrogen atom of ammonium salt, (QAS) used for the modification of bentonites on their adsorption properties, particularly in relation to styrene. It was found that the presence of at least one aromatic substituents (preferably benzyl) and an aliphatic substituents with a long carbon chin in the QAS considerably improved the adsorption properties of modified aluminosilicates. Bentonites modified with QSA showed an improved level of styrene vapour adsorption per unit of mass of the adsorbent than activated carbon. 20 refs. (Article translated from Polimery, No.2, 2005, p.143-8)