A comparative study of effects of SEBS and EPDM on the water tree resistance of cross-linked polyethylene

In this work, we investigated the effects of an ethylene propylene diene monomer (EPDM) and poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) on the water tree resistance in cross-linked polyethylene (XLPE). The XLPE/EPDM and XLPE/SEBS blend samples were prepared by melting compounding and subsequent compression molding. It was found that SEBS could greatly increase the water tree resistance of XLPE and the resistance performance was improved with SEBS content within 15 phr, whereas EPDM did not show any improvement in the water tree resistance of XLPE. The frequency dependent behaviors of the water treeing phenomena and the effects of EVA on the water tree resistance of XLPE/EPDM and XLPE/SEBS blends were also investigated. The water treeing phenomena of the blends were interpreted from the viewpoints of electro-mechanical and electro-chemical mechanisms.