A Novel Strategy for Poly(β-alanine-b-lactone)s: Sequentially HTP and AROP

Abstract

A series of poly(beta-alanine-b-lactone)s were prepared by combination of hydrogen-transfer polymerization (HTP) of acrylamide and anionic ring-opening polymerization (AROP) of beta-propiolactone, alpha-methyl propiolactone, beta-butyrolactone, and delta-valerolactone. Poly-beta-alanine (PBA) having a living anionic end-group for a further extension was obtained via HTP of acrylamide. Then, the anionic end-group on PBA chains was used as initiation sites for AROP of the lactones. By varying acrylamide feeds, a series of copolymers was obtained with a hard segment (beta-alanine) content between 6.86 and 36.82 mol%. Elemental analyses and spectral data (MALDI-MS, H-1-NMR, and FT-IR) for all new products were consistent with the proposed structures.