Microwave-assisted ring-opening polymerization of ε-Caprolactone in presence of hydrogen phosphonates

Abstract

Microwave-assisted ring-opening polymerization (MROP) of e-caprolactone (ε-CL) in the presence of hydrogen phosphonate was investigated. Poly(ε-caprolactone) with molecular weight of 8100g/mol was synthesized in 100 min at 510W microwave irradiation in the presence of 2.9% of diisopropyl hydrogen phosphonate. It was found that the MROP of ε-CL was first initiated by the trace water in the reaction mixture; a subsequent transesterification reaction occurred between the oligo(ε-caprolactone) and diisopropyl hydrogen phosphonate at the early stage of the MROP, and the resulting oligo(ε-caprolactone)-substituted hydrogen phosphonate could act as the catalyst during the MROP after diisopropyl hydrogen phosphonate was consumed out. © 2009 The Society of Polymer Science Japan.