A Novel Polypropylene Carbonate/Poly(vinyl alcohol) Blend with Multiple-Shape Memory Functions and Self-Healing Behavior Fabricated via Phase Structure Regulation

With the increasing awareness of environmental protection, shape memory materials based on environmentally friendly polymers are attracting more and more attention. However, the achieving of multifunctions remains a great challenge. Herein, to develop a novel environment-friendly shape memory polymer with multifunctions, two biodegradable polymers, i.e., poly(propylene carbonate) (PPC) and poly(vinyl alcohol) (PVA), were selected, and their melt blending was successfully realized by matching the thermal processing temperature of PVA and PPC based on our established thermal processing technology of PVA. And an effective compatibilizer, poly(vinyl acetate) (PVAc), was further introduced to help construct a temperature-persistent hydrogen bonding network at the interface between PPC and PVA. Ascribing to this enhanced interfacial interaction, the PPC/PVA blend simultaneously exhibited high mechanical performance, eminent shape fixing ratio (over 95%), and shape recovery ratio (nearly 90%). Most notably, this blend achieved the shape memory-assisted self-healing (SMASH), so it was capable of simultaneously closing and rebonding cracks, with the healing efficiency of 91%. The versatile shape memory, self-healing, and high mechanical properties enabled the PPC/PVA blend to integrate various applications, including future deployable biomedical structures, smart sensors, soft robots, etc.