CO2‐based amphiphilic block copolymers: Facile one‐step synthesis and aqueous self‐assembly

Abstract Construction of CO 2 ‐based amphiphilic block copolymers (ABCs) is an efficient method for providing CO 2 ‐based polycarbonates with self‐assembly properties in aqueous media. It is challenging to construct CO 2 ‐based ABCs by one‐step strategies from mixed monomers because hydrophilic blocks, usually composed of polar monomers, have negative effects on the synthesis of polycarbonates. In this work, we report a one‐step method to construct CO 2 ‐based ABCs obtained by simultaneous ring‐opening copolymerization (ROCOP) of CO 2 /epoxides and reversible addition‐fragmentation chain transfer (RAFT) polymerization of N ‐isopropyl acrylamide (NIPAM). A trithiocarbonate/carboxy compound was used as the bifunctional chain transfer agent, and an aluminum porphyrin complex was used as the catalyst for ROCOP, which proved to be efficient in CO 2 copolymerization even in the presence of NIPAM with strong polarity. This strategy allows flexible control over the molecular weight (5–16 kg/mol) and the hydrophilic‐hydrophobic balance (HLB 9–18) of the ABCs, and ensures narrow polydispersity Đ (1.1–1.3) of the polymers. The ABCs can further self‐assemble into micelles in water with controllable diameters and reversible phase transformation behavior with temperature changes from 25 to 40 °C. This simple route to CO 2 ‐based ABCs with multiple functions has large potential in biomedical applications.