Recyclable, robust and shape memory vitrified polyisoprene composite prepared through a green methodology

Abstract

Due to the weak mechanical performance of raw rubber, it cannot meet the actual use requirements, thus cross-linking and reinforcement have been the eternal theme of rubber materials. However, this permanent crosslinking structure brings the dilemma that the rubber materials cannot be recycled after the life cycle, which causes energy waste and serious environmental pollution. Herein, we present a facile and green methodology to prepare covalently cross-linked yet recyclable and robust polyisoprene-based vitrimer. The carboxylated carbon nanodots (CNDs) were selected as both cross-linkers and reinforcing components to react with epoxidized polyisoprene (EPI) for the construction of dynamic cross-linked networks with exchangeable β-hydroxyl ester bonds for the first time. The dynamic covalent linkages endowed the EPI-based vitrimers with reprocessability and excellent shape memory performance. In addition, the dynamic exchangeable interface enables CNDs well-dispersed in the EPI matrix, which exhibited high reinforcement efficiency on the mechanical properties of EPI composite.