One-Step Synthesis and Characterization of Poly(ε-caprolactone)-b-poly(N-isopropylacrylamide) Thermo-Responsive Block Copolymers via RAFT and ROP Techniques

Abstract

In this study, well-defined thermo-responsive block copolymers of poly(e-caprolactone)-b-poly(N-isopropylacrylamide) with narrow molecular weight distribution were synthesized in one-step via reversible addition-fragmentation chain transfer (RAFT) polymerization and ring-opening polymerization (ROP) methods using dual RAFT-ROP initiator which was obtained via the reaction of 3-chloro-1,2-propanediol with the potassium salt of ethyl xanthogenate. Thermo-responsive block copolymers were obtained in high yield and high molecular weight. The characterization of the products was accomplished by NMR and FTIR spectroscopy, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry. Furthermore, thermo-responsive properties of the copolymers were verified by UV, and fractional precipitation techniques.