Variation of natural rubber percentage add to high density polyethylene (HDPE) for electrical breakdown improvement

Polymer-based insulator was widely used in high voltage application. This research was carried out to study effect of different percentages of natural rubber blended with high density polyethylene (HDPE) polymers towards improvement of electrical breakdown and tensile strength. In this study, different percentages of natural rubber were used to blend with HDPE to form HDPE + DPNR (10%, 20%, and 30% DPNR) and HDPE + SMR 10 (10%, 20%, and 30% SMR 10) composites. The pure HDPE and composites were tested and compared for any changes and improvement in term of breakdown voltage and tensile strength. This study found that the addition of natural rubber would improve the electrical breakdown properties; with addition of 20% DPNR to HDPE gave the best results. In addition it also found that for all composites passed the minimum requirement of breakdown voltage set by standard IEC 60243 that is more than 10 kV/mm. In contrast, for the tensile strength test, the addition of natural rubber only will decrease the tensile strength of all composites compared to pure HDPE. However, all of the resulting HDPE + DPNR and HDPE + SMR 10 composites still possessed a tensile strength more than the minimum requirement set by ISO 34-1 that is 6 N/mm.