Mechanical properties of polytetrafluoroethylene composites reinforced with graphene nanoplatelets by solid-state processing

Polytetrafluoroethylene (PTFE)/graphene nanoplatelet (GnP) composites with varying GnP volume fractions are produced by solid-state milling and hot-pressing. This simple approach is able to be used for any polymer powder without any solvents. High-energy milling is performed to disperse GnPs into the PTFE in the solid-state condition. Morphology of PTFE/GnP powder and the fracture surface of PTFE/GnP composites are observed to investigate the GnP dispersion and the deformation behavior in the composites. The tensile test reveals improved mechanical properties of the PTFE/GnP composites. Yield stress of the PTFE/3 vol.% GnP composite increases by 60%, as compared to the neat PTFE. It is attributed to the interference with the movement of the PTFE chains by the randomly dispersed GnPs. A significant reinforcing effect appears on Young's modulus, which shows an increase of 223% at 3 vol.% GnP loading.