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Polymers and petroleum chemistry
494
B, A. KRErrrs~L'
Later on, on the initiative of V: A~ Kargin these invcstigatiglas were considerably extended in 1962 in another direction by N. A. Plate e t al. These studies were related to the development of methods for the controlled modification of polymers and the study of the mechanism and special features of chemical transformations in polymer -chains, in order to synthesize polyfunctional polymers, including macromoleculax catalysts, new metal-containing macromolecules, self-stabilized polymers, medical polymers, etc. Methods developed for the chemical modification of polyolelins and polyvinylchloride made ,it possible to find for the first time simple and effective means of synthesizing organic tin derivatives of polyethylene, polypropylene, polyvinylchloride and other polymers, and resulted in fundamentally new, so-called self-stabilized macromolecules, when stabilizer fragments (organic tin derivatives in this case) were incorporated on the chain of the main polymer. This principle was also applied for methylmethacrylate polymers, when a modified polymer, containing heat-stabilizing particles in the chain was synthesized (within the scope o f the, existing process for obtaining moulded polymethylmethacrylate). Studies of preparing polylithiumpolyethylene and polylithiumpolystyJ;ene-reaetive derivatives of polyhydrocarbons-enabling dozens of reactions to be carried out to render inert polyhydrocarbons functional, are of particular interest. This is a new class of macromolecular organometallic catalysts of anionic PolYmerization. A wide range of polymeric composite metal compounds and macromolecular ligands were synthesized and studied in the Institute and special features of chemical transformations of these substances explained, taking into account the polymeric nature of the reagents. Polymers were subjected to asymmetric synthesis for the first time by chemical transformations in polymer:chains (N: A. :Plate, S, L-: Dav~ydtt~e t a L ) . ~" ' : Investigations carried out in the Institute of Petrochemical Synthesis by N. A. Plate and A. D. Litmanovich e t al. who developed theoretical and experimental methods for the quantitative evaluation of the effect of adjacent units in polymer-analogue transformations, the application of which was ~Flown by 'studying of kinetics chlorination of polyethylene and hydrolysis of polymethacrylic acid "~ster~, h~d a fundamental effect on the theory and practice Of macromolecular reactions. :~"i A theory was proposed for a generalized model of a macromolecular reaction, which allows for the effect on polymer reactivity of intra- and intermolecular reactions. SUPERMOLECULAR STRUCTURE OF POLYMERS (V. A. KARGIN,G. P. ANDRIANOVA)N. F. ]]AKEYEVe t al.) STtJDIES have been carried out in the Institute from the very beginning of its activity in the field on supermolecular structure of polymers as a factor determining mechanical, technical and operational properties of polymer materials. Raising the problem itself was based on pioneer ideas of V. A. Kargin, who maintained a thesis dealing with various forms of structural organization of polymer materials, typical in view of the long-chain nature of maeromolecules and kinetic features of crystallization of polymers. Studies were also carried out in this direction in a number of scientific organizations of the country (State University of Moscow, L. Ya. Karpov Scientific Research Institute of Physical Chemistry, etc.). A specialized group was engaged by the Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences having the task of verifying experimentally the theoretical ideas developed by V. A. Kargin and seaxch for new effects related to the role of structural ordering of macromolecules in forming a complex of properties of polymer materials. As a result new experimental data were obtained which greatly enrich information about the supermolecular structure of important objects of macromolecular chemistry, such as for example, polyolefins. In addition to the fact of extremely strong influence of special features of supermolecular structure on tensile strength and breaking elongation of crystallizing polymers, a specific effect
Polymers and petroleum chemistry
495
was observed h e r e - l o w temperature high-elasticity of crystalline polymers. According to this effect high reversible deformations (with a strictly defined degree of supermolecular structure) are formed especially on the supermolecular level at temperatures well below the glass temperature of the polymer, without affecting the crystallographic cell and without changing chain conformation. It was shown that the effect is of energy form, i.e. the mechanism of high low-temperature deformations fundamentally differs from the mechanism of high-elastic deformation of elastomers. Another manifestation of large-scale motion on the level of supermolecular structures was the fact of structural change-overs of polymers by the action of shock waves (V. A. Kargin and V. I. Gol'danskii). Subsequent studies of structural and deformation properties of crystallizing polymers with varying supermolecular structure in a wide range of temperatures enabled the variation of high deformations to be observed for polymers from purely energy to purely entropy effects with a change of ratio between the reversible and irreversible components for full deformation over the entire possible temperature range. Fundamentally new results were obtained when studying the structural-mechanical transition typical of polymers from the isotropic to the anisotropic state in the range of forming a so-called "neck", which is the theoretical foundation for creating high-strength oriented polymer materials (fibres, films, etc.). Effects were also observed of the sudden influence of micro-impurities and plasticizing liquids on the deformation of crystalline polymers.
R H E O L O G Y OF P O L Y M E R S (G. V. VINOGRADOV,YU. YA. PODOL'SKH, A. YA. MALKIN, Yu. G. YANOVSKIIand V. YE. DREVAL') SIODY of polymer rheology in IPCS occupied an important position as one of the serious chapters of poIymer science, which have fundamental significance not only for theory but also for solving specific problems of processing polymers. Most important results may be characterized as follows: development of instrumental methods of studying polymer systems in various directions-shear, uniaxial and triaxial deformation under conditions of continuous, steady, prestationary and breaking conditions; low-amplitude cyclic deformation (dynamic) and deformation at high amplitudes greatly affecting the structure and properties of polymers. Considerable attention has been given to the method of evaluating the state of stress by analysing optical anisotropy; a study was made of the friction of solid polymer systems against themselves and against metals. One of the first practically important studies in the field of polymer rheology was based on the temperature-invariant description of viscosity properties of plastic (lubricating) agents, which had been proposed at the beginning of the 30s. By analysing dimensions, it was shown that this method can be used for polymer melts and filled compositions and later it became extremely popular. Intense studies have been carried out for a number of years into fibrillization of highly crystalline polymers (polyoxymethylene and linear polyethylene) in matrices of amorphous polymers. A system was proposed for fibrillization by allowing mixtures to flow through dies; this system is generally recognized. A relationship was established between viscosities of the matrix and the fibrillized polymer, ensuring the preparation of thin fibrils (many thousands of fibrils per mm 2 jet cross section). The studies were carried out with the participation of M. V. Tsebrenko (Kiev Institute of Technology) and E. Pel'tsbauer (Institute of Macromolecular Chemistry, CzechSSR Academy of Sciences). A simple method was proposed for obtaining high-modulus and high-strength fibres, which is based on stretching in a high-viscosity matrix fibrils at temperatures close to polymer melting point. Studies were made of visco-elastic characteristics of freshly filled elastomers, particularly those filled with acetylene black, containing microscopic rod-shaped particles, which ensures the formation
B, A. KRErrrs~L'
Later on, on the initiative of V: A~ Kargin these invcstigatiglas were considerably extended in 1962 in another direction by N. A. Plate e t al. These studies were related to the development of methods for the controlled modification of polymers and the study of the mechanism and special features of chemical transformations in polymer -chains, in order to synthesize polyfunctional polymers, including macromoleculax catalysts, new metal-containing macromolecules, self-stabilized polymers, medical polymers, etc. Methods developed for the chemical modification of polyolelins and polyvinylchloride made ,it possible to find for the first time simple and effective means of synthesizing organic tin derivatives of polyethylene, polypropylene, polyvinylchloride and other polymers, and resulted in fundamentally new, so-called self-stabilized macromolecules, when stabilizer fragments (organic tin derivatives in this case) were incorporated on the chain of the main polymer. This principle was also applied for methylmethacrylate polymers, when a modified polymer, containing heat-stabilizing particles in the chain was synthesized (within the scope o f the, existing process for obtaining moulded polymethylmethacrylate). Studies of preparing polylithiumpolyethylene and polylithiumpolystyJ;ene-reaetive derivatives of polyhydrocarbons-enabling dozens of reactions to be carried out to render inert polyhydrocarbons functional, are of particular interest. This is a new class of macromolecular organometallic catalysts of anionic PolYmerization. A wide range of polymeric composite metal compounds and macromolecular ligands were synthesized and studied in the Institute and special features of chemical transformations of these substances explained, taking into account the polymeric nature of the reagents. Polymers were subjected to asymmetric synthesis for the first time by chemical transformations in polymer:chains (N: A. :Plate, S, L-: Dav~ydtt~e t a L ) . ~" ' : Investigations carried out in the Institute of Petrochemical Synthesis by N. A. Plate and A. D. Litmanovich e t al. who developed theoretical and experimental methods for the quantitative evaluation of the effect of adjacent units in polymer-analogue transformations, the application of which was ~Flown by 'studying of kinetics chlorination of polyethylene and hydrolysis of polymethacrylic acid "~ster~, h~d a fundamental effect on the theory and practice Of macromolecular reactions. :~"i A theory was proposed for a generalized model of a macromolecular reaction, which allows for the effect on polymer reactivity of intra- and intermolecular reactions. SUPERMOLECULAR STRUCTURE OF POLYMERS (V. A. KARGIN,G. P. ANDRIANOVA)N. F. ]]AKEYEVe t al.) STtJDIES have been carried out in the Institute from the very beginning of its activity in the field on supermolecular structure of polymers as a factor determining mechanical, technical and operational properties of polymer materials. Raising the problem itself was based on pioneer ideas of V. A. Kargin, who maintained a thesis dealing with various forms of structural organization of polymer materials, typical in view of the long-chain nature of maeromolecules and kinetic features of crystallization of polymers. Studies were also carried out in this direction in a number of scientific organizations of the country (State University of Moscow, L. Ya. Karpov Scientific Research Institute of Physical Chemistry, etc.). A specialized group was engaged by the Institute of Petrochemical Synthesis, U.S.S.R. Academy of Sciences having the task of verifying experimentally the theoretical ideas developed by V. A. Kargin and seaxch for new effects related to the role of structural ordering of macromolecules in forming a complex of properties of polymer materials. As a result new experimental data were obtained which greatly enrich information about the supermolecular structure of important objects of macromolecular chemistry, such as for example, polyolefins. In addition to the fact of extremely strong influence of special features of supermolecular structure on tensile strength and breaking elongation of crystallizing polymers, a specific effect
Polymers and petroleum chemistry
495
was observed h e r e - l o w temperature high-elasticity of crystalline polymers. According to this effect high reversible deformations (with a strictly defined degree of supermolecular structure) are formed especially on the supermolecular level at temperatures well below the glass temperature of the polymer, without affecting the crystallographic cell and without changing chain conformation. It was shown that the effect is of energy form, i.e. the mechanism of high low-temperature deformations fundamentally differs from the mechanism of high-elastic deformation of elastomers. Another manifestation of large-scale motion on the level of supermolecular structures was the fact of structural change-overs of polymers by the action of shock waves (V. A. Kargin and V. I. Gol'danskii). Subsequent studies of structural and deformation properties of crystallizing polymers with varying supermolecular structure in a wide range of temperatures enabled the variation of high deformations to be observed for polymers from purely energy to purely entropy effects with a change of ratio between the reversible and irreversible components for full deformation over the entire possible temperature range. Fundamentally new results were obtained when studying the structural-mechanical transition typical of polymers from the isotropic to the anisotropic state in the range of forming a so-called "neck", which is the theoretical foundation for creating high-strength oriented polymer materials (fibres, films, etc.). Effects were also observed of the sudden influence of micro-impurities and plasticizing liquids on the deformation of crystalline polymers.
R H E O L O G Y OF P O L Y M E R S (G. V. VINOGRADOV,YU. YA. PODOL'SKH, A. YA. MALKIN, Yu. G. YANOVSKIIand V. YE. DREVAL') SIODY of polymer rheology in IPCS occupied an important position as one of the serious chapters of poIymer science, which have fundamental significance not only for theory but also for solving specific problems of processing polymers. Most important results may be characterized as follows: development of instrumental methods of studying polymer systems in various directions-shear, uniaxial and triaxial deformation under conditions of continuous, steady, prestationary and breaking conditions; low-amplitude cyclic deformation (dynamic) and deformation at high amplitudes greatly affecting the structure and properties of polymers. Considerable attention has been given to the method of evaluating the state of stress by analysing optical anisotropy; a study was made of the friction of solid polymer systems against themselves and against metals. One of the first practically important studies in the field of polymer rheology was based on the temperature-invariant description of viscosity properties of plastic (lubricating) agents, which had been proposed at the beginning of the 30s. By analysing dimensions, it was shown that this method can be used for polymer melts and filled compositions and later it became extremely popular. Intense studies have been carried out for a number of years into fibrillization of highly crystalline polymers (polyoxymethylene and linear polyethylene) in matrices of amorphous polymers. A system was proposed for fibrillization by allowing mixtures to flow through dies; this system is generally recognized. A relationship was established between viscosities of the matrix and the fibrillized polymer, ensuring the preparation of thin fibrils (many thousands of fibrils per mm 2 jet cross section). The studies were carried out with the participation of M. V. Tsebrenko (Kiev Institute of Technology) and E. Pel'tsbauer (Institute of Macromolecular Chemistry, CzechSSR Academy of Sciences). A simple method was proposed for obtaining high-modulus and high-strength fibres, which is based on stretching in a high-viscosity matrix fibrils at temperatures close to polymer melting point. Studies were made of visco-elastic characteristics of freshly filled elastomers, particularly those filled with acetylene black, containing microscopic rod-shaped particles, which ensures the formation