Thermal Healing of Copolyacrylate Elastomer Based on Catalyst‐Free Transketalization

Abstract Copolyacrylate can heal via dynamic covalent bonds when it is exposed to external stimuli, such as pH value, ionic strength, humidity, and light, but the incorporation of dynamic covalent bonds will result in a decrease in the thermal stability of materials. It is still a great challenge to design a healable copolyacrylate with high thermal stability. The transketalization is confirmed by the reaction of model compounds including acetophenone glycerol ketal (AGK) and ethylene glycol (EG) in the absence of catalyst. The copolyacrylate elastomers are prepared by copolymerization of methyl methacrylate (MMA), butyl acrylate (BA), 2,3‐dihydroxypropyl methacrylate (DHPMA), and ketal‐containing diacrylate as a cross‐linking agent. The results show that the ketal‐containing copolyacrylate (KCPA) can achieve a 96% of healing efficiency at 120 °C, meanwhile, it has high thermal stability. The healing of copolyacrylate elastomers originates from the transketalization between ketal and o ‐dihydroxyl groups, which is confirmed by comparison with those of the ketal‐free control samples. The study will expand the scope of self‐healing polymers based on dynamic covalent bonds.