Preparation, shape memory properties and application research of PLA/PCL‐based shape memory polymers doped with Al2O3 and lignin

Abstract

AbstractIn this paper, the influence of different material trademarks, mass ratios, the melt mass‐flow rate (MMFR) and molecular weights (MW), mold and injection temperatures, Al2O3 powder and lignin on the shape memory properties of PLA/PCL SMP material (PPSM) were then analyzed in detail by different characteristic methods. Besides, three promising applications (Origami metamaterials and variable‐stiffness grippers) are provided utilizing the PPSM doped with Al2O3/lignin. Eventually, a compensating strategy was discussed to improve the final configuration of the SMP after multi‐cycles. The shape memory recovery ratios could be improved by increasing the MMFR of PLA and the MW of PCL. The addition of 2 g‐Al2O3 could shorten the recovery time, while the addition of 2 g‐lignin could increase the thermal‐recovery force and mechanical performance. The shape memory rate under 20 g weights, initial peak forces at room and high temperatures of the origami metamaterials could reach 57%, 2027.29 N and 17.49 N, respectively. The tensile force of banding rebars could reach 150.29 N, which is promising to apply into the construction field.