Sequence Design of Poly(ester-co-carbonate): A Unique Example of Degradable Self-Healing Copolymers

Abstract

Degradable and self-healing polymers are considered next-generation materials since they can tackle both the end-of-life issues and the long-standing longevity of synthetic materials. Here, we design a series of aliphatic polyester-polycarbonate copolymers combining degradability and self-healability using commodity monomers comprising ε-caprolactone (ε-CL), cyclohexene oxide (CHO), and CO₂. These copolymers are synthesized by random copolymerization catalyzed by a dinuclear salen-Mn catalyst under low CO₂ pressure, affording randomly distributed carbonate units on a poly(ε-caprolactone) (PCL) chain. High molar mass copolymers with controllable components and microstructures are obtained by regulating the reaction conditions. Different from corresponding triblock copolymers, the random copolymers exhibit autonomous self-healing capability under ambient or even harsh conditions without any external intervention. The outperformance of random copolymers in self-healing is ascribed to the interchain diffusion and reconstruction of nanodomains. This sequence regulation method may serve as a general facile strategy for the design and synthesis of other self-healing copolymers.