Developments in the Field of Isomerization Polymerizations*

Abstract

OUTLINE AND DEFINITIONSThis paper concerns developments in the field of isomerization polymerizations. Although this a r e a of polymer chemistry is very young, it is in the process of vigorous development.Isomerization polymerizations a r e polyaddition reactions in which the propagating species rearranges to energetically preferred structures prior to propagation so that the repeat unit of the polymer does not possess the structure of the original monomer. Defining equation: nA Oj>nOnly isomerization polymerizations of hydrocarbons proceeding via carbonium ion mechanisms will be discussed in detail. Two o r three examples involving Ziegler-Natta type catalysts will also be touched upon.A rather arbitrary but useful classification of this field is based upon the type of rearrangement involved in the propagation step. Types of rearrangements can further be subdivided by particular processes:I. Isomerizations by bond (or electron) rearrangement.