Anionic Alternating Copolymerizability of Epoxide and 3,4-Dihydrocoumarin by Imidazole

Abstract

This paper describes the alternating character in the copolymerization of glycidyl phenyl ether (GPE) and 3,4-dihydrocoumarin (DHCM) by 2-ethyl-4-methylimidazole (EMI) as an initiator. DHCM, which is an aromatic lactone that does not undergo its homopolymerization under anionic conditions, underwent the copolymerization with GPE by EMI. In the present copolymerization, formation of the GPE−DHCM alternating sequence and that of the GPE−GPE sequence competed, and the former was always the predominant one. The maximum content of the alternating sequence (90%) was achieved when the feed ratio GPE/DHCM was 1. The obtained copolymer was a polyester, for which the ester linkage was cleavable by reduction with lithium aluminum hydride. The resulting compound inherited the structure of the alternating sequence, and its high yield (90%) supported the high alternating character of the copolymerization.