Characterization and modeling of elastocaloric effects of shape memory poly(cyclooctene)

The elastocaloric cooling effect (eCE) of natural rubbers has been demonstrated in the context of cold storage; however, programming at room temperature is only possible at high strain rates. This study reports that shape memory cross-linked poly(cyclooctene) (PCO) exhibits an enhanced eCE at a relatively moderate strain rate due to its strain-induced crystallization behavior during deformation at room temperature. The elastocaloric heating and cooling effects of PCO were predicted using Green-Lagrangian strains obtained by 3D finite element analysis (FEA) with a suitable constitutive model and thermodynamic parameters such as the Clausius-Clapeyron factor and entropy changes. Good agreement between the simulation and experimental results suggests that implementation of the current method into 3D FEA can facilitate studies of portable cooling devices made of shape memory polymers.