Effect of Industrial Graphene and Few Layer Graphene on Physical, Mechanical and Dielectric Properties of Polycarbonate

Abstract

Polymer Nanocomposites (PNC’s) have gained significant interest in the field of polymer research due to their enhanced Physical, Thermomechanical, Mechanical, and Electrical characteristics with respect to neat matrix. In the present study Polycarbonate/Graphene nanocomposites were synthesized. Graphene was obtained from two sources (industrial Graphene and Few layered Graphene) and then it was dispersed in the polymer matrices by Solution mixing method in different ratios to prepare PNC’s. These PNC’s then were characterized for physical, mechanical and electrical properties using various techniques. SEM and XRD data confirmed a good dispersion of both types of graphene in the polycarbonate matrix. Thermal studies of the PNCs prepared showed that glass transition temperature of polycarbonate nanocomposites was increased as compared to the neat polycarbonate and a maximum of 15˚C increase in Tg was observed in case of PC/IG nanocomposites at 0.5% loading of industrial graphene. Dielectric spectroscopy of the samples prepared showed an improvement in dielectric properties like dielectric constant, dielectric loss and dissipation factor of the polycarbonate after the inclusion of both Few Layer Graphene and Industrial Graphene in low frequency region. In this regard a gradual increase in dielectric values of the nanocomposites was observed as the graphene filler contents were increased until a threshold value of the filler contents. These threshold values for the aforementioned dielectric properties were 0.5% and 1% for Industrial Graphene and Few Layer Graphene respectively. AC conductivity, however, remained unchanged as compared to neat polycarbonate in a range of applied field frequency. Mechanical testing showed a decline in the tensile strength and % elongation of the nanocomposite samples as compared pure polycarbonate. Elastic modulus, however, was increased up to 300MPa more than the pure polycarbonate 0.5% loading of industrial graphene. Possible mechanisms and logical/theoretical reasons for these effects on each characteristic have been prescribed in this work. Data analysis concludes that, dielectric properties were better improved by inclusion of FLG as compared to IG while thermal properties and Elastic modulus were better modified by IG as compared to FLG inclusion in polycarbonate matrix.