Synthesis and Characterization of Temperature-Responsive Block Copolymers Using Macromonomeric Initiator

Abstract

Temperature-responsive block copolymers, poly(2-(dimethyl amino)ethyl methacrylate)-b-poly(N-isopropylacrylamide) [PDMAEMA-b-PNIPAM], have been prepared by a combination of the redox polymerization and the reversible addition-fragmentation chain transfer (RAFT) polymerization. For this purpose, poly-N-isopropylacrylamide (PNIPAM-Cl) was acquired by redox polymerization of N-isopropylacrylamide (NIPAM) using 2-(2-chloroethoxy)ethanol and Ce(NH4)(2)(NO3)(6) was used as a catalyst. Poly(DMAEMA-b-NIPAM) temperature-responsive copolymers were prepared via RAFT of 2-(dimethyl amino)ethyl methacrylate) (DMAEMA) in the presence of macromonomeric initiator (macro-CTA) which was obtained via the reaction of PNIPAM-Cl with the potassium salt of ethyl xanthogenate. The synthesized temperature-responsive block copolymer was characterized using multi-instruments and methods such as nuclear magnetic resonance spectroscopy, F(f)ourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis, differential scanning calorimetry, scanning electron microscope and UV-Vis.