Experimental and modeling investigation on thermodynamic effect of graphene doped shape memory epoxy composites

The thermodynamic effect of shape memory graphene oxide/epoxy resin (GO/EP) composites with different fractions of GO were investigated by molecular dynamics (MD) and shape memory performance experiments. The microscopic effect mechanisms of GO doping and aggregation of GO on the thermodynamic properties of shape memory epoxy resin were investigated based on the correspondent MD simulations. The experimental results shows that with the increasing of GO contents, the shape retention ratio of the shape memory GO/EP composites with 1.25 wt% GO content decreased by 8.40%, while the shape recovery ratio increased by 16.26%. The MD simulation results indicate that the chemical bonds between the GO layer and the EP molecule play an important role for improving the shape memory performance. In addition, it was found that the agglomeration of GO reduces the recovery performance of the shape memory GO/EP composites. When GO content was 10 wt%, the recovery performance of GO agglomerated composites was 14.38% lower than that of GO uniformly dispersed, and 3.30% lower than that of pure shape memory EP. The MD simulations are verified by comparing them with the shape memory experimental results of shape memory GO/EP composites. • A molecular dynamics model of shape memory GO/EP composites was established. • The fast recovery interval of shape memory GO/EP composites with 1.25 wt% GO is 30 s earlier than that of shape memory EP. • The agglomeration of GO sheets in shape memory GO/EP composites significantly reduces the shape recovery properties. • The tensile recovery ratio perpendicular to the GO direction is 21.73% higher than that along the GO direction.