Preparation and thermomechanical characterisation of graphene nanoplatelets/low-density polyethylene composites

The thermomechanical properties of Graphene Nanoplatelets (GNPs)/low-density polyethylene (LDPE) composites were investigated and characterised to understand the effect of nanoscaled reinforcement in the thermoplastic matrix. Results show that the presence of the filler does not produce a change in the microscopic structure of the polymer. However, on a macroscopic scale, graphene platelets limit the mobility of the polymer chains, resulting in an increase in stiffness and in some cases, strength of the composite. Orientation of Graphene Nanoplatelets in the LDPE matrix was evaluated by testing composites made with two different manufacturing techniques (compression moulding and blown extrusion). A comparison between experimental data and predictions using the Halpin-Tsai model shows that the orientation of the nanoplatelets due to the extrusion process leads to better mechanical properties than those obtained with the randomly oriented graphene resulting from the compression moulding technique.