A LLDPE-Based XLPE Insulation Material Using BIPB as Crosslinking Agent

In this paper, a different type of cross-linking agent, bis (1- (tert-butylperoxy)-1-methylethyl)-benzene (BIPB), was investigated for XLPE insulation. In order to explore its cross-linking effect and the difference on the performance of XLPE between using BIPB and DCP (Dicumyl peroxide) as crosslinking agent, with the linear-low-density polyethylene (LLDPE) as base material, the relationship between the content of BIPB on the gel content was established, and the effects of the gel content on the crystallinity and DC breakdown characteristics of XLPE as well as its mechanical properties were further compared. The experimental results shows that the performance of XLPE under similar gel content using different crosslinking agent is similar. It can be concluded that with the increase of peroxide content, the gel content of the samples is increasing, which can represent the increase of the crosslinking degree of XLPE. And the crystallinity of XLPE decrease with the increase of gel content, and its DC breakdown strength increases with the increase of crosslinking degree under 70°C. What's more, both crystallinity and crosslinking degree affect the mechanical properties of XLPE, which leads to the change of tensile strength and elongation at break. It can be found that it only costs about 3/5 of DCP content to achieve the similar crosslinking effect for BIPB, that is, the crosslinking efficiency of BIPB is better.