AC conductivity and dielectric properties modification of UHMWPE by graphene fillers

In this report, a multi-layer functionalized graphene was mixed to UHMWPE. Composite samples with 0.05 wt%; 0.1 wt%; 0.15 wt% and 0.5 wt% of functionalized graphene have been manually mixed. The AC conductivity of these samples was then measured using Broadband Dielectric Spectroscopy (BDS) at low voltage. The measurements were conducted at room temperature, 40 °C, 60 °C and 80 °C, respectively. The results showed that the electrical conductivity of UHMWPE/functionalized graphene composites increased fast as the content of functionalized graphene increases from 0.15 wt%. In order to analyze the influence of the encapsulation technique, one type of sample which contains 0.05 wt% of functionalized graphene was processed by ball-milling. The dielectric responses of hand-mixed and ball-milled samples were obtained under high electric fields. The dielectric loss ε″ of the hand-mixed sample at 50 Hz under 2 kV/mm was higher by a factor of 2 when compared to the corresponding ball-milled sample.