Breakdown properties of high density polyethylene and polypropylene blends

Abstract

In high voltage (HV) applications, thermoplastic polymers are preferred to be used as insulators especially in cable technology. Polyethylene (PE) and polypropylene (PP) have been widely used due to their advantages of having good mechanical strength, thermal properties and electrical properties. However, there are weaknesses for each type of polymer (either PE or PP) that can be improved. Degradations and failures of insulators may cause a big impact to high voltage equipment when flashover occurred, thus damaging the equipment. The use of polymer blends may compensate the weaknesses of each polymer. In this paper, thermoplastic polymer blends composed of high density polyethylene (HDPE) and polypropylene (PP) homopolymer were formulated through melt blending method. The breakdown properties of the polymer blends with different compositions were investigated and analysed. Five samples of polymers composed of 100% HDPE, 80% HDPE and 20% PP, 50% HDPE and 50% PP, 20% HDPE and 80% PP, and 100% PP were chosen for investigation purposes. The breakdown results obtained were analysed using Weibull software. The results showed that thermoplastic blends revealed good breakdown performance. These improvements can be transformed into favourable choices and cost effective solutions in electrical power systems.