Polylactide–Poly(6-methyl-ε-caprolactone)–Polylactide Thermoplastic Elastomers

Abstract

Amorphous ABA type block aliphatic polyesters can be useful as degradable and biorenewable thermoplastic elastomers. These materials can be prepared by sequential ring-opening transesterification polymerization (ROTEP) reactions and can exhibit a range of physical properties and morphologies. In this work a set of amorphous polylactide–poly(6-methyl-e-caprolactone)–polylactide aliphatic polyester ABA triblock copolymers were prepared by consecutive controlled ring-opening polymerizations. Ring-opening polymerization of neat 6-methyl-e-caprolactone in the presence of 1,4-benzenedimethanol and tin(II) octoate afforded α,ω-hydroxyl-terminated poly(6-methyl-e-caprolactone). High conversions of 6-methyl-e-caprolactone (>96%) afforded polymers with molar masses ranging from 12 to 98 kg mol–1, depending on monomer-to-initiator ratios, polymers with narrow, monomodal molecular weight distributions. An array of polylactide–poly(6-methyl-e-caprolactone)–polylactide triblock copolymers with controlled molecular weig...