Two-way shape memory polymer with “switch–spring” composition by interpenetrating polymer network

In the present work, a novel molecular strategy was employed to fabricate a two-way shape memory polymer (2WSMP), which is an interpenetrating network (IPN) with elastomeric and crystalline components leading to a "switch–spring" composition. In this 2WSMP the switch, a PCL crystalline network, is responsible for the reversible shape shrinkage. While the spring, the compressed PTMEG elastomeric network, provides the push force for shape expansion. This IPN polymer has the desired two-way shape effect (2WSME) as proved by DMA.