An investigation into the electrical properties of rubber blends for insulators

This paper focuses on testing silicone rubber (SiR) and ethylene-propylene-diene monomer (EPDM) blends which are applied as outdoor high voltage insulating materials. The study undertakes an investigation of the properties of aged specimens of SiR, EPDM and a blend of SiR/EPDM materials by exposure to ultra-violet radiation. Microscopic surface observations are demonstrated to inspect surface degradation after aging for blends of SiR/EPDM of different compositions. Measurements show that the dielectric strength of the specimen materials improve by an increase of EPDM content in the SiR/EPDM blend; whereas SiR produces better mechanical endurance after UV aging process. The investigation reveals that the blend between two materials induces results that have a moderate improvement in both the electrical and mechanical characteristics undertaken.