Synthesis of Macrocyclic Poly(ε‐caprolactone) by Intramolecular Cross‐Linking of Unsaturated End Groups of Chains Precyclic by the Initiation

Abstract

Biodegradable cyclic polyesters are synthesized by using an ε-caprolactone polymerization initiated by a cyclic tin alkoxide, followed by the addition and sequential polymerization of a few units of α-(1-acryloxyethyl)-ε-caprolactone. Tadpole-shaped polyesters with two tails of controllable length are readily prepared by this procedure (see picture).