Solvent-dependent self-assembly behaviour of block copolymers having side-chain amino acid and fatty acid block segments.

Abstract

Reversible addition–fragmentation chain-transfer (RAFT) polymerization has been used for the controlled synthesis of block copolymers containing side-chain fatty acid and amino acid block segments, namely, poly(2-(methacryloyloxy)ethyl stearate)-block-poly(tert-butyloxycarbonyl phenylalanine methacryloyloxyethyl ester) (PSAMA-b-P(Boc-Phe-HEMA)) with fixed PSAMA block length and variable block lengths of P(Boc-Phe-HEMA). Because of different solubilities of PSAMA and P(Boc-Phe-HEMA) segments in various organic solvents, PSAMA-b-P(Boc-Phe-HEMA) formed a micellar morphology with PSAMA core and P(Boc-Phe-HEMA) coronas in N,N-dimethylformamide, dimethyl sulphoxide and acetonitrile. Upon deprotection of Boc groups, the block copolymers can undergo transformation to amphiphilic block copolymers, which showed interesting self-assembly in methanol and water.