Polymers containing the cyclopentyl and cyclohexyl groups

Abstract

AbstractPolymers have been prepared from a group of monomers containing the cyclohexyl and cyclopentyl groups. These monomers were of the type (C6H11)(CH2)nCHCH2, (where n = 0–3) and (C5H9)(CH2)nCHCH2 (where n = 0−1). Both Ziegler‐Natta and Friedel‐Crafts catalysts were used. By comparison of the infrared spectra of corresponding polymers prepared with the two types of catalysts, it has been shown, for the cyclohexyl compounds, that intramolecular hydride transfers take place to a significant extent during the propagation step of the Friedel‐Crafts polymerizations. These hydride transfers result in the formation of a tertiary carbonium‐ion end which, on propagation, leads to a polymer in which cyclohexyl groups are part of the main chain. The cyclopentyl compounds, however, do not behave in this way. In this case, the relative reactivities of the tertiary and secondary carbonium ions are such that propagation through the latter is favored. Attempts to polymerize 2,4‐spiroheptane and 2,5‐spirooctane to give model compounds for the “rearranged” polymers are also reported.