Synthesis and Characterization of New Block Copolymers with Poly(ethylene oxide) and Poly[3(S)-sec-butylmorpholine-2,5-dione] Sequences

Abstract

Four different types of polydepsipeptide-polyether block copolymers were synthesized via ring-opening polymerization of 3(S)-sec-butylmorpholine-2,5-dione (BMD) in the presence of hydroxytelechelic poly(ethylene oxide) (PEO) with stannous octoate as a catalyst.The polymers were an AB block copolymer, an ABA block copolymer, an (A)2B star shaped copolymer and an (A)2B(A)2 copolymer, where A is a poly[3(S)-sec-butylmorpholine-2,5-dione] (PBMD) and B a poly(ethylene oxide) block. The molar ratio of BMD to PEO was varied to obtain copolymers with different weight fractions of PBMD blocks ranging from 59.8 to 96.7 wt.-%. The crystallinity of the PEO phase in the copolymers decreases in the following order: AB > (A)2B > ABA > (A)2B(A)2 . The static contact angle θ decreases with increasing PEO content in the block copolymers.