High-performance and cost-effective melt blended poly(ether ether ketone)/expanded graphite composites for mass production of antistatic materials

In this study unfunctionalized expanded graphite (EG) was incorporated into poly(ether ether ketone) (PEEK) using twin-screw extrusion and injection moulding to manufacture cost-effective PEEK/EG composites for mass production of high-performance antistatic materials. Direct current electrical conductivity, morphology, rheological and thermal properties of the composites were investigated. At an EG loading of 5 vol%, the electrical conductivity exhibited an abrupt increase to 1.45 x 10(-5) S m(-1) which was in the required range of electrical conductivity of antistatic materials. The frequency dependence of the storage modulus of the melt containing 2 vol% EG decreased significantly at low frequencies. Viscosity did not increase much with the addition of EG in comparison with other nanofillers such as carbon nanotubes. The crystallinity of PEEK increased to 41.11% from 35.87% upon addition of 3 vol% EG. EG improved the thermal stability of PEEK by an increase in the initiation temperature of its decomposition steps. (c) 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.