Study on Nonlinear Conductivity of CCTO/EPDM Rubber Composites

Abstract

Researches of the theories and application of polymer composites with nonlinear conductivity are useful for dealing with the nonuniform electrical fields widely existing in the cable accessory insulation. In the present work, we fabricated CCTO (CaCu3Ti4O12)/EPDM (Ethylene Propylene Diene Monomer) composites and investigated their breakdown strength, dielectric and nonlinear conductivity properties in detail; the microstructures of fillers and composites were characterized by scanning electron microscopy (SEM) and X-ray diffraction. CCTO particles are uniformly dispersed in CCTO/EPDM composites, and the composites showed nonlinear conductivity with electric field changes. When the CCTO particle content is low, the conductivity of CCTO/EPDM composites does not present obvious nonlinearity. However, when CCTO content exceeds 2 vol %, the conductivity experiences a nonlinear change with increasing electric field strength and the threshold field (Eth) of nonlinear conductivity declines with the increase of CCTO contents. In addition, it can be found from experiment and simulation results that 8 vol % CCTO/EPDM exhibit significant nonlinear conductivity and dielectric properties as expected, and homogenizing the electrical field much more effectively. Therefore, this paper offers a preliminary discussion about the variation trend of nonlinear conductivity CCTO/EDPM composites, providing an effective reference to solve the application of nonlinear conductivity materials for cable accessories.

Investigating the non‐linear conductivity properties of silicone rubber co‐modified with doped calcium copper titanate @ zinc oxide and grafted glycidyl methacrylate

“…The composites were verified to have the ability to homogenise the electric field using simulation software. 22 Yamano et al investigated the effect of grafted voltage stabilisers on the electrical conductivity of low-density polyethylene (LDPE). The experimental results showed that grafted voltage stabilisers could reduce the ambient temperature conductivity of LDPE.…”

“…They found that 8 vol% CCTO/EPDM exhibited significant non‐linear conductivity. The composites were verified to have the ability to homogenise the electric field using simulation software 22 . Yamano et al.…”