Development of shape memory epoxy resin/polyethylene glycol film based on molecular dynamics simulation and performance investigation

Based on the molecular dynamics (MD) simulation of glass transition temperature (T-g) and hydrogen bonding in the composite system of epoxy resin (Ep) and polyethylene glycol (PEG), this work developed shape memory Ep/PEG (EpP) films with controllable thermal response, recycling and reprocessing functions using melt dispersion and polymerizing-pressing processes. EpP films with different PEG contents exhibit excellent shape memory performance, among which the shape recovery rate of EpP-5 film can reach 92.7%, which can recover from complex structures to the initial shape. The PEG in the composite system can effectively regulate the thermal and mechanical properties of EpP, especially increasing the strain at break and reducing the T-g. Compared with EpP-0 film. The T-g of EpP-15 film increased by 40 degrees C and the strain at break increased by 18.56%. Furthermore, compared with the EpP-0 film, the recycling-reprocessing temperature of EpP-15 film has been reduced by 75 degrees C. In summary, based on MD simulation, shape memory EpP films with controllable thermal response, recycling, and reprocessing functions have been successfully developed, and have shown considerable application prospects in the field of intelligent materials.