Intrinsic healable and recyclable thermoset epoxy based on shape memory effect and transesterification reaction

A shape memory and healable epoxy was prepared based on esterification between diglycidyl ether of bisphenol A and tricarballylic acid. The healing was achieved through transesterification at the fracture surface between two epoxy blocks in a confined space assisted by shape recovery force. The shape recovery of the compression programmed epoxy at elevated temperature tightly closed the gap between the two epoxy blocks, whose fracture surfaces are saw-cut and not perfectly matched during healing, which is the worst case scenario for the healing test. A healing efficiency of -60% was achieved. This suggests that, for naturally cracked surfaces, which have smoother fracture surfaces and better surface alignments during healing, higher healing efficiencies could be expected. We believe that the combination of shape memory and intrinsic healing capability within one network will broaden the applications of thermosets and enable recycling. (C) 2016 Elsevier Ltd. All rights reserved.