Direct Synthesis of Biotinylated Stimuli-Responsive Polymer and Diblock Copolymer by RAFT Polymerization Using Biotinylated Trithiocarbonate as RAFT Agent

Abstract

A new reversible addition−fragmentation chain transfer (RAFT) agent, biotinylated trithiocarbonate, was successfully synthesized. Temperature-responsive biotinylated polymer, poly(N-isopropylacrylamide) (PNIPAAm) and water-soluble poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA), have been prepared in one-step via RAFT polymerization using biotinylated trithiocarbonate as the RAFT agent. The results show that the polymerizations of N-isopropylacrylamide (NIPAAm) and N-(2-hydroxypropyl)methacrylamide (HPMA) are of living characters, and the corresponding polymers produced have ending biotin group. Biotin-ended diblock copolymer of PHPMA and PNIPAAm was also prepared by RAFT polymerization of NIPAAm using biotinylated PHPMA as macro chain transfer agent. The biotinylated PHPMA-b-PNIPAAm can form a new kind of core−shell nanostructure with biotin groups on the surface reversibly induced by temperature.