High-Temperature Triple-Shape Memory Polymer with Full Recovery through Cross-Linking All-Aromatic Liquid Crystalline Poly(ester imide) under Reduced Molding Temperature

High thermal transition temperature, good processing feature, and full recovery of two temporary shapes are three necessary properties of triple-shape memory polymers (Tri-SMPs) for cutting-edge fields such as aerospace deployable structures, high temperature sensors, and actuators; however, it is still an interesting project with great challenges to prepare these functional polymers. Herein, without using solvent and high curing temperature (>300 °C), a new kind of thermally resistant Tri-SMP (LCPEI-EPEA) with two distinct glass transition temperatures (Tg = 93 and 218 °C) and 100% shape recovery ratios of two recovery processes was developed, which was prepared through building cross-linked networks based on acetylene terminated all-aromatic liquid crystalline poly(ester imide) (LCPEI) and reactive epoxy oligomer with acetylene side groups (EPEA). The relationship between cross-linked structures and integrated properties is intensively discussed. Unique copolymer molecular structures and chemical cross-linked points endow LCPEI-EPEA with excellent triple-shape memory performance. The obvious advantages of high thermal transition temperature and good processing property make the preparation of LCPEI-EPEA highly competitive with that of other advanced polymers with triple-shape memory effects.