Nowadays, polymers have been widely used in semiconductor field. The most famous thermosetting polymers that was being used was epoxy due to its excellent properties. Often conductive fillers of carbon allotropes such as graphite, graphene, graphene oxide and carbon nanotubes were added into the epoxy main matrix to change the nature of epoxy into conductive polymer composites. In this study, different loadings of graphene nano platelets (GNP) incorporated into main matrix of epoxy via solution mixing method followed by ultrasonication, targeted to improve the mechanical, thermal and electrical properties of the epoxy/graphene composite. Phenolic resin was blended with epoxy, forming co-existing miscible blend was aimed to improve the mechanical and thermal stability of the blend system. It was shown that the epoxy/graphene composite has the best flexural and fracture toughness properties at 0.4 vol%. The percolation of graphene was reported at 1.0 vol% and thermogravimetry analysis (TGA) showed that incorporation of graphene did not affect the thermal stability of the epoxy/graphene composites. With the graphene loading fixed at 1.0 vol% prior to the percolation of the nanoplatelets, different amount of phenolic resins was blended with the epoxy main matrix with the phenolic resin acts as a crosslinker to improve the mechanical and thermal stability of the blend system. It was reported that the optimum results of mechanical properties and thermal stability were found in ratio of epoxy:phenolic at 100:20 phr. Addition of phenolic resin into the epoxy/graphene system did not seem to have any effect on the electrical conductivity properties due to high miscibility between both resins where selective localizations of graphene nano platelets were inhibited.
