Fabrication of EPDM/LDPE shape memory composites: the effect of vulcanization and crystals

In this paper, a series of ethylene propylene diene monomer/low density polyethylene (EPDM/LDPE) composites with the shape memory effect (SME) are prepared by polymer blending method. The cross-link structure and crystallization are regulated by the impact of thermodynamic factor and content of peroxide, and the influence on SME is also investigated. The results demonstrate that the interfacial adhesion originates from the good interfacial compatibility and interfacial grafting reaction between the phases, and the cross-linked chemical structure improves interfacial adhesion and forms abundant tiny LDPE crystals, which plays a crucial role in exploring the SME and improving the mechanical performance of EPDM/LDPE composites. A balanced state between the mechanical properties and SME is achieved when dicumyl peroxide content is 1 wt.%; the tensile strength and elongation at break reach 19.2 MPa and 1499%, respectively, while the shape fixation ratio ( R f ) and shape recovery ratio ( R r ) are ~ 99% and ~ 85%, respectively. Graphical abstract