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Polymers and petroleum chemistry
Polymers and petroleum chemistry
489
bilized complexes of metal compounds of variable valency. Therefore, the reaction takes place not only on the surface but also in the entire volume of catalyst particles, enabling maximum efficiency of GCS to be achieved which is comparable with the efficiency of homogeneous analogues. GCS may be formed as a set of macroscopic solids of given form an dimensions, which are strong and elastic polymer compositions that can be readily separated from reaction products and are permeable to initial monomers. These systems are used in a way which is similar to that of heterogeneous catalysts. General principles of designing GCS are formulated, technical methods of forming a polymercarrier, developed and detailed studies made of special features of catalytic action in dimerization, oligomerization and polymerization of unsaturated hydrocarbons. In addition to their ability to be separated readily from reaction products, most important special features of catalytic action of GCS is the exceptionally high stability of action over a period of time (thousands of hours) at increased temperatures (100-200°), possibility of repeated recovery and increased adaptation to changed external conditions. These properties of GCS determine the prospects of practical application. Among processes having passed experimental testing and re. commended for practical application high temperature (solution) polymerization of ethylene and dimerization of lower olefins are the most significant. GCS developed are original and have no analogues in foreign or Soviet practice.
SPONTANEOUS POLYMERIZATION OF VINYLPYRIDINES AND MATRIX SYNTHESIS OF MACROMOLECULES (V. A. KABANOVet aL)
SrONTAN~OUS polymerization of quaternized vinylpyridines was developed and examined in detail in the Institute; the process takes place by a specific Zwitterion mechanism. This opened up the way to the possible preparation of a wide range of quaternized poly-4-vinylpyridinium salts, which may be used as flocculants, complex-furming agents in reactions with proteins, membrane-active agents, etc. The study of matrix polymerization-synthesis of macromolecules in the presence of other macromolecules - matrices and receiving from the latter elements of structural-chemical information, are of considerable interest. The first example was polymerization of 4-vinylpyridine (4-VP) on macro-anions of various poly acids, studied in the Institute of Petrochemical Synthesis. When carrying out this process kinetic and structural matrix effects are observed. The study of the mechanism of matrix polymerization of 4-VP served as an impulse for investigations into matrix polymerization in many countries of the world and finally, resulted in the formation of an independent trend in the chemistry of high molar mass compounds. Products of matrix polymerization are: polymer-polymer complexes of the matrix and secondary chain. Crystallizing polymer-polymer complexes based on isotactic polyacrylic acid and, subsequently, on various polyphosphates are products of matrix polymerization. An important problem of matrix polymerization is the separation of secondary chain formed during synthesis from the initial matrix. This problem was first solved by carrying out matrix polymerization on matrices that undergo disintegration easily-polyphosphates and polyaminoesters. Polyaminoesters are a new class of polymer compound synthesized in the Institute of Petrochemical Synthesis. They are water-soluble, physiologically inert compounds and are of separate interest from the point of view of forming from them a qualitatively new type, the so-called two-letter matrices.
489
bilized complexes of metal compounds of variable valency. Therefore, the reaction takes place not only on the surface but also in the entire volume of catalyst particles, enabling maximum efficiency of GCS to be achieved which is comparable with the efficiency of homogeneous analogues. GCS may be formed as a set of macroscopic solids of given form an dimensions, which are strong and elastic polymer compositions that can be readily separated from reaction products and are permeable to initial monomers. These systems are used in a way which is similar to that of heterogeneous catalysts. General principles of designing GCS are formulated, technical methods of forming a polymercarrier, developed and detailed studies made of special features of catalytic action in dimerization, oligomerization and polymerization of unsaturated hydrocarbons. In addition to their ability to be separated readily from reaction products, most important special features of catalytic action of GCS is the exceptionally high stability of action over a period of time (thousands of hours) at increased temperatures (100-200°), possibility of repeated recovery and increased adaptation to changed external conditions. These properties of GCS determine the prospects of practical application. Among processes having passed experimental testing and re. commended for practical application high temperature (solution) polymerization of ethylene and dimerization of lower olefins are the most significant. GCS developed are original and have no analogues in foreign or Soviet practice.
SPONTANEOUS POLYMERIZATION OF VINYLPYRIDINES AND MATRIX SYNTHESIS OF MACROMOLECULES (V. A. KABANOVet aL)
SrONTAN~OUS polymerization of quaternized vinylpyridines was developed and examined in detail in the Institute; the process takes place by a specific Zwitterion mechanism. This opened up the way to the possible preparation of a wide range of quaternized poly-4-vinylpyridinium salts, which may be used as flocculants, complex-furming agents in reactions with proteins, membrane-active agents, etc. The study of matrix polymerization-synthesis of macromolecules in the presence of other macromolecules - matrices and receiving from the latter elements of structural-chemical information, are of considerable interest. The first example was polymerization of 4-vinylpyridine (4-VP) on macro-anions of various poly acids, studied in the Institute of Petrochemical Synthesis. When carrying out this process kinetic and structural matrix effects are observed. The study of the mechanism of matrix polymerization of 4-VP served as an impulse for investigations into matrix polymerization in many countries of the world and finally, resulted in the formation of an independent trend in the chemistry of high molar mass compounds. Products of matrix polymerization are: polymer-polymer complexes of the matrix and secondary chain. Crystallizing polymer-polymer complexes based on isotactic polyacrylic acid and, subsequently, on various polyphosphates are products of matrix polymerization. An important problem of matrix polymerization is the separation of secondary chain formed during synthesis from the initial matrix. This problem was first solved by carrying out matrix polymerization on matrices that undergo disintegration easily-polyphosphates and polyaminoesters. Polyaminoesters are a new class of polymer compound synthesized in the Institute of Petrochemical Synthesis. They are water-soluble, physiologically inert compounds and are of separate interest from the point of view of forming from them a qualitatively new type, the so-called two-letter matrices.