Creep and recovery of polystyrene composites filled with graphene additives

In this work, we investigate the creep and recovery behaviours of polystyrene (PS) composites filled with two-dimensional chemically reduced graphene oxide (CRGO) sheets. Incorporation of CRGO into PS polymer is found to significantly improve the creep resistance and recovery properties. The results are compared with the creep and recovery of the corresponding composites with carbon black (CB) and carbon nanotube (CNT) nano-additives, and it is observed that both the CB/PS and CNT/PS systems present worse efficiencies in reducing the creep and unrecovered response. The CRGO sheets with corrugated structures possess higher specific surface area and display better dispersion in the PS matrix compared to the CB or CNT nano-additives, which should produce strong sheet/matrix interfacial interaction to restrict the mobility of polymer chains. The formation mechanisms are further interpreted based on the analysis from the dynamic mechanical properties and thermo-gravimetric results.