Back SearchTitle: PORE FORMATION IN CROSSLINKED ELASTOMERS EXPOSED TO HIGH TEMPERATURE
Page Range: p.T/1-4
Author(s): Gaidadin A N; Petryuk I P; Kablov V F
File size: 122K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
It was shown previously that, on exposure to high temperatures (above 180 deg C), a new gaseous phase was formed in crosslinked elastomer composites, which led to a sharp reduction in the mechanical properties of the material and to an increase in its deformability. In this study, the physicochemical processes that occurred in an ethylene-propylene rubber matrix were analysed in order to explain the development of this phenomenon. It was shown that, on exposure to high temperatures, pore formation occurred in the crosslinked elastomers, with a gas-filled composite with an integral macrostructure being formed. The cause of the development of a porous structure in the crosslinked elastomer was the low solubility at elevated temperatures of gaseous products of decomposition of the vulcanisation process. The formation of a porous macrostructure at high temperatures was determined by diffusion factors. 12 refs. (Article translated from Kauch.i Rezina, No.1, 2008, p.7-10)
Title: CALCULATING THE SPECIFIC COHESIVE ENERGY OF CERTAIN RUBBERS
Page Range: p.T/5-6
Author(s): Shmurak I L
File size: 69K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
Calculated values of the specific cohesive energy, using Small's method, were compared with known experimental values for different rubbers, including SBR, polyisoprene, polybutadiene, nitrile rubber and various other butadiene copolymers. It was shown that for most of the rubbers studied the discrepancy between calculated and experimental values of specific cohesive energy was 0.35 to 4.9%, but that this discrepancy increased for nitrile rubber with increasing content of acrylonitrile units in the rubber. 2 refs. (Article translated from Kauch.i Rezina, No.1, 2008, p.10-11)
Title: PHYSICAL MODIFICATION OF DIENE RUBBERS AS A METHOD FOR IMPROVING THE PROCESSING PROPERTIES OF RUBBER MIXES AND THE PHYSICOMECHANICAL PROPERTIES OF THE VULCANIZED RUBBERS. II.
Page Range: p.T/7-8
Author(s): Dorozhskin V P; Galimova E M; Il'yasov R S
File size: 54K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
The effect of the time since physical modification of diene rubbers, using a method described in part I (Kauch.i Rezina, No.5, 2007, p.18), on the processing properties of the rubbers and the properties of standard sulphur-filled rubber mixes based on them was studied. Modified polyisoprene rubber and modified NR were used. It was shown that, with increase in the storage time of modified rubbers, the plasticity of the rubbers and the plasticity of the rubber mixes based on them changed little. The rigidity of polyisoprene rubber and of the mix based on it decreased, while it increased in NR and the mix based on it. 2 refs. (Article translated from Kauch.i Rezina, No.1, 2008, p.11-12)
Title: STUDY OF THE THERMAL CURING OF UNSATURATED AROMATIC POLYESTERS AND OLIGOESTERS BY MEANS OF IR SPECTROSCOPY
Page Range: p.T/9-12
Author(s): Vologirov A K; Kumykov R M; Mikitaev A K
File size: 104K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
The thermal structure formation of unsaturated polyarylates, block copolymers and oligoesters based on 2,2-di(4-oxy-3-allylphenyl)propane was investigated. The curing in air was studied by IR spectroscopy. The data obtained showed that the polymerisability of unsaturated polymeric and oligomeric systems depended on the structure and composition of the initial polyesters and oligoesters. The presence of strongly polar substituents markedly increased the activity of the allyl group. The allyl group nearest to the substituents appeared to be more active. 2 refs. (Article translated from Plast.Massy, No.12, 2007, p.14-16)
Title: SYNTHESIS AND PROPERTIES OF RESOL-TYPE PHENOL-FORMALDEHYDE COPOLYMERS CONTAINING PHTHALIDE AND PHTHALIMIDINE GROUPS
Page Range: p.T/13-16
Author(s): Machulenko L N; Shitikov V K; Nechaev A I; Komarova L I; Abrosimova A I; Salazkin S N
File size: 79K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
Cooligophenol-formaldehyde resols were synthesised on the basis of phthalimidine-containing phenols, including resols combined with phthalide-containing phenols. 3,3-bis(4-Hydroxyphenyl)phthalimidine and 2-phenyl-3,3-bis(4'-hydroxyphenyl)phthalimidine were used as phthalimidine-containing phenols and phenolphthalein as the phthalide-containing phenol. The mechanical and thermal properties of the polymers were studied. The specific impact strength and the flexural stress causing failure of the cured phenol-formaldehyde resols based on phthalide- and phthalimidine-containing phenols were similar to those of the FF-40 resin based on phenolphthalein. The heat resistance of the cured polymers based on phthalide- and phthalimidine-containing phenols was higher than that of a homopolymer based on phenolphthalein imide and was similar to that of FF-40. 11 refs. (Article translated from Plast.Massy, No.12, 2007, p.16-19)
Title: SYNTHESIS AND STUDY OF THE PROPERTIES OF POLYAMIDES AND POLYAMIDE ESTERS BASED ON TRIARYLMETHANE-SERIES DIAMINES
Page Range: p.T/17-21
Author(s): Borukaev T A; Tlenkopachev M A; Tkhakakhov R B
File size: 110K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
Polyamides and polyamide esters were synthesised by low-temperature polycondensation of triarylmethane-series diamines with terephthalic and isophthalic acid dichlorides. The molecular structure of the polymers was studied by IR spectroscopy and elemental analysis and their thermal and mechanical properties were investigated. The polyamides and polyamide esters produced, which had triarylmethane fragments in the main chain, were shown to possess a combination of useful physicochemical properties. They could be readily processed from solution or from the melt for the production of strong fibres and films of various types for use under harsh conditions. 8 refs. (Article translated from Plast.Massy, No.12, 2007, p.19-23)
Title: PRODUCTION OF LUMINESCENT COMPOSITES BASED ON PE AND EUROPIUM(III)
Page Range: p.T/23-27
Author(s): Mardaleishvili I R; Zaichenko N I; Shienok A I; Marevtsev V S; Anisimova O M; Anisimov V M
File size: 82K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
A PE-based luminescent composite was prepared by synthesising luminescent complex europium compounds directly during the formation of the composite. The effectiveness of mechanochemical action on a mixture of different complexing components was investigated and the progress of the mechanochemical reaction was monitored by the luminescent method from the appearance and ignition of luminescence in the red region of the spectrum, excited by light with a wavelength of 365 nm. A luminescent product was formed in all the europium compound systems studied. The reaction proceeded most fully during the synthesis of a complex with phenanthroline. Each system required optimum reaction conditions to achieve maximum effectiveness of luminescence of the composite. 8 refs. (Article translated from Plast.Massy, No.12, 2007, p.26-30)
Title: EFFECT OF HEAT AND LIGHT AGEING ON THE THERMAL EXPANSION AND SWELLING OF WOOD-FILLED PLASTICS
Page Range: p.T/29-31
Author(s): Kiseleva O A; Yartsev V P
File size: 80K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
The influence of the duration of heat ageing and of UV irradiation on the swelling rate of wood-filled plastics, i.e. chipboard, wood-fibre board and plywood, all containing phenol-formaldehyde resin, was studied with variation of the set constant temperatures. The kinetics of relative swelling versus holding time in water were determined. With increase in the heat ageing time, there was a sharp increase in the activation energy and in the initial swelling rate. The results indicated that, after heat and light ageing, the macrostructure of wood-filled composites, determined by the filler, was retained but rupture of chemical bonds of the phenol-formaldehyde resin occurred. 5 refs. (Article translated from Plast.Massy, No.12, 2007, p.30-31)
Title: PRINCIPLES OF PRODUCTION OF LOW-FLAMMABILITY WOOD-FILLED POLYETHYLENE COMPOSITES
Page Range: p.T/33-39
Author(s): Volkov V P; Zelenetskii A N; Sizova M D; Rudakova T A; Zelenetskii S N; Artem'eva N Yu; Kechek'yan A S; Obolonkova E S
File size: 196K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
Composite materials of low flammability(LFCs), based on PE and ground wood, were prepared and characterised. It was shown that an important principle for lowering flammability was the use of a solid-state extrusion method for producing low-flammability composites based on LDPE, wood filler and various flame retardants, including adducts of melamine with cyanuric acid and phosphoric acids, with simultaneous formation of nanoparticles of oxidation inhibitors, heat stabilisers, antioxidants and coking catalysts. SEM and X-ray microprobe analysis were used to study the process of coking during the combustion of LFCs based on PE, ground wood and different intumescent systems. It was established that, during the formation of the coked-foam surface layer, the major part of the phosphorus passed into this layer and evidently played an important role in its formation. New self-extinguishing composites with improved thermal and physicomechanical properties were produced by compression moulding. 10 refs. (Article translated from Plast.Massy, No.12, 2007, p.32-36)
Title: STRUCTURAL POLYMERIC MATERIAL MODIFIED WITH CARBON NANOTUBES
Page Range: p.T/41-48
Author(s): Burya A I; Tkachev A G; Mishchenko S V; Nakonechnaya N I
File size: 153K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
The results of research into the creation of a structural polymer composite using Taunit carbon nanotubes and an aromatic polyamide (Phenylone S-2) are presented and discussed. It is shown that filling of the polyamide with 3-10 wt % carbon nanotubes improves the service characteristics of the initial polymer. The heat resistance is increased by 150-187 deg K and the linear thermal expansion coefficient decreases by a factor of 1.2. The yield point in compression and the elastic modulus increase by a factor of 1.2-1.5, respectively, the friction coefficient is 1.5-1.8 times lower than that of Phenylone-2 and the wear resistance increases by a factor of 1.2-3 over the entire filling range studied. 16 refs. (Article translated from Plast.Massy, No.12, 2007, p.36-41)
Title: THERMOVISCOELASTICITY PROBLEM FOR A MULTILAYER INHOMOGENEOUS POLYMERIC CYLINDER
Page Range: p.T/49-51
Author(s): Yazyev B M; Litvinov S V; Yazyev S B
File size: 179K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
The plane-strain state of a hollow two-layer inhomogeneous polymeric cylinder was examined theoretically. The material of each layer possessed different physicomechanical properties which were a continuous function of temperature and, consequently, of the coordinates of the r"1th layer. If it was assumed that the temperature field and the force loads changed slowly with time, then the creep problems could be regarded as quasi-stationary. 4 refs. (Article translated from Plast.Massy, No.12, 2007, p.44-45)
Title: FRACTAL MODEL OF IMIDISATION IN THE PRESENCE OF A NANOFILLER
Page Range: p.T/53-55
Author(s): Nafadzokova L K; Kozlov G V; Zaikov G E
File size: 106K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
A structural analysis of the processes occurring in the course of solid-phase imidisation was carried out. The kinetics of solid-phase imidisation of polyamide acid synthesised from 4,4'-oxydianiline and pyromellitic anhydride, both without filler and with the addition of 2.5 and 7 wt % sodium montmorillonite, were studied. The acceleration of imidisation as the content of nanofiller increased was caused by change in the structure of the macromolecular coil owing to interfacial interactions with the surface of sodium montmorillonite. The relative proportion of interacting phase increased as the content of nanofillers increased and, with a nanofiller content of about 17.5 wt %, this phase occupied the entire reaction system. Reduction of the activation energy of imidisation as the nanofiller content increased was also due to structural factors, particularly reduction in the fractal dimension of the macromolecular coil. 10 refs. (Article translated from Plast.Massy, No.12, 2007, p.45-47)
Title: EXTRUSION HEADS FOR THE MANUFACTURE OF POLYMER CASINGS FOR PROTECTING PIPELINES AGAINST CORROSION
Page Range: p.T/57-60
Author(s): Panov A K; Beloborodova T G; Anasova T A; Zaikov G E
File size: 160K
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Issue Year: ipsat
Volume: 36
Issue No: No.2
Abstract
Extruder head designs for the manufacture of pipeline outer and inner casings are presented, including cross-sections and longitudinal sections of the heads, and a procedure is presented for making calculations relating to the shaping channels of extrusion heads. It is shown that the proposed extruder head design makes it possible to produce casings for piping with the required dimensions and the necessary quality. 3 refs. (Article translated from Plast.Massy, No.12, 2007, p.48-50)