Effect of Synergistic Reduction of Dicumyl Peroxide and Antioxidant Content on Crosslinking Characteristics of XLPE

Abstract

Cross-linked polyethylene (XLPE) used in high voltage cables usually contain different content of dicumyl peroxide (DCP) and antioxidant. The antioxidant, DCP and cross-linking by-products in the crosslinking process will affect the purity of XLPE cable insulating materials and thus affect the insulating properties. Reducing the additives content is the key to improve the insulation performance of XLPE. DCP and antioxidant have antagonistic effects on the crosslinking properties of XLPE. In this work, three kinds of XLPE cable insulating materials with different composite systems were prepared to study their crosslinking characteristics. The gel content experimental and DSC test results show that the content of DCP determines the rate of crosslinking reaction, the higher the DCP content, the lower the apparent activation energy and the higher the crosslinking reaction rate. The addition of antioxidant can inhibit the crosslinking efficiency of the cable insulating materials. Appropriately reducing the amount of antioxidant is beneficial to the improvement of crosslinking efficiency. The DC breakdown strength of three samples can meet the demand of high voltage cables when the DCP and antioxidant content were synergistic reduced. Thus, the properly synergistic reduction of DCP and antioxidant content has little effect on the properties of the XLPE. This research provides guidance for the optimization of additives content in the XLPE cable insulating materials.