Synthesis and Self-Assembly of CO_2?Temperature Dual Stimuli- Responsive Triblock Copolymers

摘要

Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) with a β-cyclodextrin (β-CD) at the chain end was synthesized via atom transfer radical polymerization (ATRP); poly(ε-caprolactone) (PCL) with a ?CC? segment and an adamantane (Ada) group at two ends, respectively, was prepared through ring-opening polymerization (ROP), and poly(Nisopropylacrylamide) (PNIPAM) with a ?S?C(S)?S? segment, which can be converted into a thiol group, was yielded by reversible addition?fragmentation chain transfer polymerization (RAFT). A supramolecular triblock stimuli-responsive copolymer PNIPAM-b-PCL-b-PDMAEMA having good biocompatibility with PNIPAM and PDMAEMA hydrophilic segments and PCL hydrophobic segment was constructed by thiol?ene Michael addition and host?guest interaction. The triblock copolymer could self-assemble into vesicles and respond to carbon dioxide (CO_2) gas and temperature reversibly. Under the stimulation of CO_2, the vesicular assemblies swelled obviously; while raising the temperature from 25 to 40 ℃, the assemblies displayed a conversion between vesicles and spherical micelles.