Failure of elastomers under external stress concentrators

It is shown that the shear resistances of undeformed unfilled hydrocarbon rubbers (natural rubber, PKhP, SKN-40, SKF-32, SKN-18, SKS-30, SKEP), in contrast to their markedly differing tensile strengths, are identical.Scientific-Research Institute for the Rubber Industry, Moscow. Translated from Mekhanika Polimerov, Vol. 9, No. 3, pp. 564–566, May–June, 1963.     

Investigation of the deformation of a rubbery network polymer (SKN-40) in various types of states of stress

From the experimental data on equilibrium uniaxial and nonsymmetrical and symmetrical biaxial tension and pure and mixed shear it follows that the deformation behavior of SKN-40 crosslinked butadiene-nitrile copolymer is more accurately described by the Bartenev-Khazanovich high-elastic potential. The potential of the classical statistical theory of high elasticity of network polymers does not describe different types of states of stress with the same value of the material constant.Lenin Moscow State Pedagogical Institute, Laboratory for Problems in Polymer Physics. Leningrad Branch of the Scientific-Research Institute of the Rubber Industry. Translated from Mekhanika Polimerov, No. 5, pp. 840–845, September–October, 1971.     

The life of loaded rubbers

It has been demonstrated experimentally that the dependence of failure time on stress (in the coordinates log –log and log –) for loaded rubbers based on SKN-26 and SKN-40, elastomers, natural rubber, polychloroprene rubber and SKMS-30 ARKM-15 with channel and lamp blacks, fine colloidal silica, "Aerosil," and whiting has a discontinuity. The assumption has been made that the discontinuity is the result of a change in the nature of the failure, associated with greater or smaller rupture of chemical bonds. This is corroborated by the difference in the values of the apparent activation energy and its dependence on the stress in the two parts of the curve, as well as the displacement of the discontinuity into the shorter failure times region with an increase in the test temperature and a reduction in the amount or activity of the filler.Scientific-Research Institute of the Rubber Institute, Moscow. Translated from Mekhanika Polimerov No. 3, pp. 539–541, May–June, 1970.     

Calculation of the resistance to the flow of polymeric systems through short channels

A method is proposed for calculating the pressure drop associated with the flow of polymeric systems (solutions, melts, and rubber blends) through short capillaries in which the steady-state flow regime is not established. The method is based on the assumption that the duration of deformation in the prestationary stage plays a decisive role. The results of the calculations are in good agreement with the experimental data.All-Union Scientific-Research and Design-Engineering Institute of the Rubber Industry, Volzhskii. Topchiev Institute of Petrochemical Synthesis, Academy of Sciences of the USSR, Moscow. Volgograd Polytechnic Institute. Translated from Mekhanika Polimerov, No. 1, pp. 171–174, January–February, 1973.     

Calendering mechanics of viscoelastic materials (communication 1)

The kinematics and dynamics of the deformation of a viscoelastic material (rubber mix) between the rolls of a calender are considered. Approximate calculations are presented for the elastic recovery of the sheet after it passes through the nip in terms of the calendering speed, the geometry of the deformation zone, and the rheological properties of the rubber mix. Equations are also given for estimating the vertical thrust and torque.Scientific-Research Institute of the Tire Industry, Moscow. Translated from Mekhanika Polimerov, No. 3, pp. 539–545, May–June, 1969.     

Investigation of the fiber packing density in a unidirectional composite

Recommendations are made for designing a unidirectional composite with an optimal arrangement of the fibers. The effect of the fiber diameter distribution law on the packing density is investigated.All-Union Scientific-Research Institute of Glass-Reinforced Plastics and Glass Fiber, Moscow. Moscow Institute of Electronic Machine-Building. Translated from Mekhanika Polimerov, No. 3, pp. 538–541, May–June, 1976.     

Nonsteady deformation of SKN-18 rubber

In certain polymers, in certain conditions of temperature and deformation, orientation processes predominate over processes of thixotropic structural breakdown.Scientific-Research Institute of Rubber and Latex Goods, Moscow. V. I. Lenin Moscow State Pedagogical Institute. Translated from Mekhanika Polimerov, No. 2, pp. 350–351, March–April, 1974.     

Equilibrium conditions for multilayered anisotropic viscoelastic plates in a complex state of stress

Systems of linear differential-difference equations describing the complex state of stress of multilayered viscoelastic and elastic plates are obtained.Moscow Institute of Electronic Machine Building; All-Union Scientific-Research Institute of Glass-Reinforced Plastics and Glass Fiber, Moscow Region. Translated from Mekhanika Polimerov, No. 2, pp. 281–288, March–April, 1973.     

Water absorption and its effect on rubber strength

The effect of the swelling of rubbers in water and their recovery on the tear strength of the material has been investigated and a mechanism of water absorption is proposed. It is shown that there is a fundamental difference between the mechanism of water absorption and swelling in solvents. The strength of a rubber dried after being kept in water is anomalously high. This effect is explained in terms of the proposed polymer-nonsolvent interaction mechanism.É. A. Ter-Gazaryan State Scientific-Research and Design Institute of Polymer Adhesives, Kirovakan. Moscow Technological Institute of the Meat and Dairy Industry. Translated from Mekhanika Polimerov, No. 1, pp. 136–138, January–February, 1970.     

Plane-strain investigation of rubber specimens using a variable Poisson's ratio

It is shown that with an accuracy sufficient for practical purposes the strains of rubber models in a plane state of strain coincide with the values computed from the generalized Hooke's law with variable Poisson's ratio determined from the constant-volume condition.Scientific-Research Institute of the Rubber Industry, Moscow. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 345–347, March–April, 1969.     

Dynamic mechanical properties of multicomponent polymeric compositions

The mechanical relaxation processes in rubber-polymer compositions have been investigated by the forced nonresonance vibration method. A method of evaluating black-filled polymer mixtures with advantages over microscopic methods is proposed.Scientific-Research Institute of the Tire Industry, Moscow. V. I. Lenin Moscow State Pedagogical Institute, Laboratory of Problems in Polymer Physics. Translated from Mekhanika Polimerov, No. 1, pp. 138–141, January–February, 1970.     

Friction and wear of certain thermoplastic materials in physiological solution

The wear resistance of certain thermoplastics has been subjected to comparative investigation together with the velocity dependence of the coefficients of friction at various pressures and after various periods of contact with a model physiological solution.Priorov Central Scientific-Research Institute of Traumatology and Orthopedics. Moscow Technological Institute of the Food Industry. Second Moscow Pirogov State Medical Institute. Translated from Mekhanika Polimerov, No. 6, pp. 1116–1119, November–December, 1971.     

Changes in the supermolecular structure and physico-mechanical properties of a polycarbonate subjected to supplementary heat treatment

The possibility of modifying the supermolecular structure of polycarbonate by suitable supplementary heat treatment is demonstrated. An improvement in the physico-mechanical and service properties controlled by the supermolecular structure of the polycarbonate is noted.Departmental Plastics Laboratory, Ministry of the Machine-Tool and Tool Industry of the USSR, Moscow. Moscow Mendeleev Chemical Engineering Institute. State Scientific-Research Institute of Machine Science, Moscow. Translated from Mekhanika Polimerov, Vol. 5, No. 2, pp. 347–349, March–April, 1969.     

Effect of modification on the structure and and mechanical properties of chlorosulfonated polyethylene films

Structure formation in chlorosulfonated polyethylene films is described. Modification with phenol-formaldehyde resin leads to a change in the supermolecular structures, which are stabilized by introducing 1% aluminum diisobutoxymonoacetoacetate into the system. It is shown that modifying the chlorosulfonated polyethylene leads to the formation of stable supermolecular structures and a considerable improvement in the mechanical properties of the films.State Scientific-Research and Planning Institute of the Paint and Varnish Industry, Moscow. Karpov Scientific-Research Physico-Chemical Institute. Riga Polytechnic Institute. Translated from Mekhanika Polimerov, No. 3, pp. 387–390, May–June, 1969.     

A method of making specimens of free varnish films for physicomechanical testing

The author describes a method of preparing film specimens of a required shape by casting varnish in an open mold.All-Union Scientific-Research Institute of Electromechanics, Moscow Region. Translated from Mekhanika Polimerov, No. 2, pp. 372–373, March–April, 1974.     

Properties of PS-B polystyrene foam in pure tension and compression

The results of testing polystyrene foam of five different densities in pure tension and compression are presented.All-Union Scientific-Research Institute of Physicotechnical and Radio-Engineering Measurements, Moscow Region. Translated from Mekhanika Polimerov, No. 5, pp. 808–812, September–October, 1971.     

Relation between the shear and longitudinal viscosity coefficients for concentrated polymer solutions

A relation between the shear and longitudinal viscosity coefficients is obtained on the basis of the theory of flow of polymeric systems in the single relaxation time approximation. A comparison of the shear and longitudinal viscosity coefficients for polymer melts and solutions shows that the relation obtained is valid over a broad stress region.Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow. Scientific-Research Institute of Synthetic Fibers, Moscow. Translated from Mekhanika Polimerov, No. 1, pp. 124–131, January–February, 1973.     

Nonsingular configurations of field systems in the relativistic theory of gravitation

Scientific-Research Institute of Nuclear Physics at the Moscow State University. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 88, No. 3, pp. 467–476, September, 1991.     

A nonlinear,viscoflastic ring under an external pressure

The flattening and loss of stability of a nonlinear viscoelastic ring at various initial eccentricities is investigated with due allowance for instantaneous, nonlinear deformations.Scientific-Research Institute of Mechanics, M. V. Lomonosov State University, Moscow. Translated from Mekhanika Polimerov, No. 6, 1073–1080, November–December, 1972.     

Physicomechanical properties of polyamides with chopped-strand reinforcement

The physicomechanical properties of AS-30 and KS-30 glass-reinforced polyamides have been determined at normal and elevated temperatures under various kinds of short-time and long-time loading.Riga Polytechnic Institute, All-Union Scientific-Research Institute of Glass-Reinforced Plastics and Fiberglass, Moscow Region. Translated from Mekhanika Polimerov, No. 3, pp. 411–415, May–June, 1971.