Physical cross-linked aliphatic polycarbonate with shape-memory and self-healing properties

As one of the stimulus-responsive intelligent materials, shape memory polymers (SMPs) gained increasing attention for possessing the benefits of lightweight, low density, easy processing, and large shape variables. It is of great significance to enhance self-healing properties and mechanical properties of SMPs. Herein, we synthesized an aliphatic polycarbonate monomer named MMC (5-methyl-5-[(4-methoxy)-benzyloxycarbonyl]-1,3-dioxan-2-one) by a two-step method. The cross-linked network was constructed by ring-opening copolymerization of 5-methyl-5-benzyloxycarbonyl-1, 3-dioxan-2-one (MBC) and MMC with mPEG43 as an initiator and Sn(Oct)2 as a catalyst. The acquired elastomer achieves a stretchability of up to 777.7 %, which is significantly higher than that of the homopolymer of MBC. The elastomer presents a shape recovery rate of 97.8 within 42 s at 37 °C and can maintain excellent stretchability up to 772.0 % which is 99.3 % of the initial value after repair at 37 °C for 6 h. The introduction of MMC heightens the viscosity of the cross-linked network and effectively improves its stretching and self-healing performance, which offers new candidates for future body-sensors, stimuli-responsive materials, and wound healing.