Covalent crosslinks turn natural Eucommia ulmoides gum/polybutene‐1 composites into multiple shape memory materials

Abstract A series of shape memory natural Eucommia ulmoides gum (EUG)/polybutene‐1 (PB‐1) composites were developed based on polymer blending. It was revealed that covalent crosslinks turned typical “sea‐island” phase morphology in the EUG/PB‐1 blend into a chemical co‐continuous structure, which played a vital role in promoting mechanical performances and fulfilling multiple shape memory effect dominated by the two well‐separated crystalline and melting phase transitions. Although the increase in cross‐linking density was a disadvantage to mechanical performances and shape fixing, the composite with more covalent crosslinks displayed better shape recovery capacity. The EUG/PB‐1 composite crosslinked by 0.4 phr diycumyl peroxide (DCP) displayed the highest shape fixing capacity, while the best shape recovery ability was given by that crosslinked by 1.6 phr DCP. The findings would provide a new technique to develop intelligent materials applied in smart packaging and hot‐shrinkable products.