The shape memory properties of multi-layer graphene reinforced poly(L-lactide-co-epsilon-caprolactone) by an atomistic investigation

In this paper, an atomistic investigation was performed to reveal the dependence of the graphene content on the shape memory effect of the multilayer graphene reinforced poly (L-lactide-co-e-caprolactone). Uniaxial compression deformation was carried out to show the shape memory effect of the graphene composites. The temperature response of the composites was obtained during shape recovery. It is observed that the composites with higher graphene content exhibit larger recovery ratio and are more sensitive to temperature during a gradual warming recovery. The graphene composites show good reusable properties and the shape of composites is able to fully recover by constant temperature recovery tests. Especially, the graphene of the composite was subjected to a separate heating test to check the role of the graphene in shape recovery of the composite, where electro-induced indirect heating was qualitatively simulated. It is shown that the recovery first appeared in composites with the most content of graphene. The polymer will have a temperature hysteresis compared with graphene in composites. The shape recovery trajectory of graphene and the evolution of the interaction between graphene and polymers during the process of shape memory were clearly presented to reveal the mechanism how graphene promotes the performance of shape memory. This research can provide a guidance for obtaining composite materials with ideal shape memory effect.