Novel Shape‐Memory Polymer with Two Transition Temperatures

Summary: This communication describes a novel kind of PMMA‐PEG semi‐interpenetrating network (semi‐IPN) which shows excellent shape‐memory behavior at two transition temperatures, the T m of the PEG crystal and the T g of the semi‐IPN. Based on a reversible order‐disorder transition of the crystals below and above the T m of PEG, and the large difference in storage modulus below and above the T g of the semi‐IPN, the polymer has a recovery ratio of 91 and 99%, respectively. Shape‐memory phenomena of PMMA‐PEG2000 semi‐IPN. magnified image Shape‐memory phenomena of PMMA‐PEG2000 semi‐IPN.