Living Cationic Polymerization of δ-Valerolactone and Synthesis of High Molecular Weight Homopolymer and Asymmetric Telechelic and Block Copolymer

Poly(δ-valerolactone) [poly(δVL)] of high molecular weight (∼40 000) and low polydispersity index (∼1.05) was prepared by activated monomer cationic ring-opening polymerization of δ-VL initiated by the alcohol/HCl·Et 2 O system. A series of functional alcohols, e.g., 9-anthracenemethanol, 2-hydroxyethyl acrylate, 3-buten-1-ol, 2-bromoethanol, and 5-norbornene-2-methanol, were successfully used to prepare asymmetric telechelic poly(δVL), i.e., chains end-capped by the functional group of the alcohol in α-position and by an ω-hydroxyl group. Ring-opening polymerization of δ-VL in the presence of α-methoxy-ω-hydroxylpoly(ethylene oxide) and poly(ethylene glycol) led to amphiphilic di- and triblock copolymers, respectively. The polydispersity index of all these (co)polymers was low (∼1.10).