SYNTHESIS AND MODIFICATION OF POLYMERS CONTAINING A SYSTEM OF CONJUGATED DOUBLE BONDS.

This review paper is concerned with preparation of two broad classes of hydrocarbon copolymers containing a system of conjugated double bonds randomly distributed in the chains, i. e. , (1) ethylene-propylene based terpolymers and (2) triene-isobutene copolymers. They can be obtained by using coordinate and cationic catalysts, respectively. The diene functionality can be linear and inserted in the chains of (2) or pendant-endocyclic, -exocyclic and -linear when it belongs to (1). The reactivity of the diene groups in typical reactions, i. e. , with free radicals, chlorinating or oxidizing agents, during Diels-Alder additions, was investigated with both polymer and low molecular weight model compounds for elucidating the reaction mechanism of the reactions considered. With the results obtained one may conclude that in several cases the polymers investigated possess a reactivity which is qualitatively and quantitatively different from that shown by the corresponding polymers containing monoenic unsaturation. Furthermore, the peculiar reactivity of each dienic group permits the choice of functionality which is most suitable for the post-modification reaction.