The paper from Prof. Tao XIE's Group titled Thermoset Shape-Memory Polyurethane with Intrinsic Plasticity Enabled by Transcarbamoylation (DOI: 10.1002/anie. 201602847) was published in Angew. Chem. Int. Ed. recently and it was rated as the Very Important Paper.
Polyurethanes as traditional engineering materials provide superior bonding, abrasion and aging resistance and are widely used as foams, rubbers and coatings. Thermoset shape memory polyurethanes are known for their superior thermomechanical properties which can fixed temporary shapes and recover to their permanent shapes upon external stimulus. However, their chemical crosslinking nature typically leads to unable to redefine the permanent shape. Contrary to current knowledge, we reveal here that a classical thermoset shape-memory polyurethane is readily capable of permanent reshaping (plasticity) after a topological network rearrangement that is induced by transcarbamoylation. By employing the Jianzhi technique (also known as kirigami), unexpected shape-shifting versatility was observed for this otherwise classical material.
