New trends in high polymer synthesis, and structural characteristics of the new materials

Abstract

AbstractThe development of the polymer chemistry during the last decade is characterized by the existence of several new methods of polymerization, e. g. the isomerization polymerization of aliphatic hydrocarbons, the oxidative catalytic polymerization of aromatics, the photochemical polyaddition, the 1.3 and 1.4 dipolar polycycloadditions, the two step polycondensation processes. Some of these methods have already been applied on an industrial scale. Simultaneously new catalytic procedures were discovered, some of which permit stereoregular copolymerization, and very recently stereo‐elective polymerization. These different aspects will be considered successively.The isomerization polymerization in which the chain growth is characterized by alternate addition isomerization steps, is illustrated by several examples, and compared to the polymerizations with previous monomer isomerization, as in the case of β‐olefins.The stepwise oxidative coupling of different 2.6 disubstituted phenols, with oxygen in the presence of amine complexes of copper salts is considered from kinetic and structural point of view and compared with the oxidative FRIEDEL‐CRAFTS reaction on aromatic hydrocarbons.Two types of photochemical polyadditions are considered on the basis of the cyclomerization reaction, in which cyclobutane rings are formed by dimerization of olefins (in solution and in the solid state), and of the reductive dimerization, e. g. of bisarylketones into polypinacols.The use of 1.3 dipolar cycloaddition for the synthesis of heterocyclic rings containing polymers is illustrated and some properties of these polymers are described. Similarly the 1.4 DIELS‐ALDER cycloaddition is exemplified by the synthesis of polyphenylenes as described from biscyclopentadienones or (and) bis‐phenylenebispyrones and diethinylbenzene.Only short mention will be made on the synthesis of thermally stable polymers by polyheterocyclization, e. g. single strand benzoxazole‐ and benzthiazole‐imide copolymers and Kapton fibre, and double strand ladder polypyrrolone‐anthrachinone fibres. New catalytic procedures are finally briefly commented as far as they offer possibilities for the synthesis of new polymers and regular copolymers. Some properties of these new polymers are reported.