CATIONIC POLYMERIZATION OF 2-ALKENYLFURANS - 1. GENERAL FEATURES.

Abstract

This paper reviews the major features of the cationic polymerization of 2-vinylfuran, 2-isopropenylfuran, 2-vinyl-5-methylfuran, and 2-isopropenyl-5-methylfuran, in methylene chloride using trifluoroacetic acid as initiator. Only the latter monomer gives polymers of regular structure in the temperature range minus 78 to 30 degree C. The others exhibit important side reactions leading to alkylation of the furan ring at 5C (when this is not methylated) and to polyunsaturated chains (if the carbon in the alpha position to the ring is tertiary). The kinetics of the polymerization are affected by these side reactions. A brief analysis is made of the initiation, propagation, and termination reactions, and of the nature of the active species. General discussion is included in the paper.