Amphiphilic block copolymers via acyclic diene metathesis polymerization: one-step synthesis, characterization, and self-assembly

摘要

The novel amphiphilic block copolymers consisted of polyphosphoesters (PPEs) and poly(ethylene glycol) segments were synthesized relying on acyclic diene metathesis (ADMET) polymerization. Two different α, ω-diene phosphate monomers first were polymerized to yield unsaturated PPEs with high molecular weights and reasonable polydispersity index. Then, by applying different amounts of poly(ethylene glycol) methyl ether acrylate as a chain stopper in this ADMET step growth polymerization led to the preparation of AB diblock and ABA triblock copolymers in a onestep, one-pot procedure via using the selectivity of olefin cross-metathesis between acrylates and terminal olefins. Importantly, there has been a good control over polymerization process and relatively low polydispersity index of these resulting copolymers. The prepared amphiphilic block copolymer with a fixed chain length can self-assemble spontaneously in THF/H_2O to form polymeric micelles, which was characterized by DLS, AFM, and TEM.