Synthesis and characterization of catechol containing thermo-responsive copolymers

Abstract

Stimuli responsive polymers have been drawn interests in various fields, due to their ability to change structures and physical or chemical properties in response to external stimuli. Among them, poly(N-isopropylacrylamide) (PNIPAM) is one of the most widely studied synthetic polymers showing LCST behavior in aqueous solution. While much research effort has been focused on polymer network formation with mussel-inspired polymers, catechol functional groups in the mussel-inspired polymers show interesting behavior of pH dependent metal ion chelation. In this study, we have synthesized dual responsive copolymer systems consisting of thermo-responsive PNIPAM and metal ion-responsive poly(dopamine acrylamide) (PDA) by reversible addition-fragmentation chain transfer (RAFT) polymerization method. The metal ion induced hydrogel formation was conducted with random copolymer Poly(NIPAM-co-DA), and thermo-responsive swelling-deswelling property was studied. Furthermore, self-assembly of amphiphilic diblock copolymer of PNIPAM-b-PDA was carried out to investigate the morphology transition depending on temperature. These tunable temperature responsive copolymer systems are expected to find applications in drug delivery systems, sensors and actuators.