PAA-g-PPO Amphiphilic Graft Copolymer: Synthesis and Diverse Micellar Morphologies

Abstract

A series of well-defined amphiphilic graft copolymers consisting of hydrophilic poly(acrylic acid) backbone and hydrophobic poly(propylene oxide) side chains were synthesized by sequential reversible addition−fragmentation chain transfer (RAFT) polymerization and atom transfer nitroxide radical coupling (ATNRC) chemistry followed by selective hydrolysis of poly(tert-butyl acrylate) backbone. A new Br- containing acrylate monomer, tert-butyl 2-((2-bromopropanoyloxy)methyl) acrylate, was first prepared, and it can be polymerized via RAFT in a controlled way to obtain a well-defined homopolymer with narrow molecular weight distribution (Mw/Mn = 1.06). Grafting-onto strategy was employed to synthesize PtBA-g-PPO well-defined graft copolymers with narrow molecular weight distributions (Mw/Mn = 1.05−1.23) via ATNRC reaction between Br-containing PtBA-based backbone and poly(propylene oxide) with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) end group using CuBr/PMDETA or Cu/PMDETA as catalytic system. The final ...