Extruded co-continuous polyester-polyalkene-carbon black composites: Influence of polyester glass transition on electrical properties

Abstract

Co-continuous extruded polyester-carbon black filled polyalkene blends exhibit a slightly positive temperature coefficient, which depends on the nature of the polyester. From studies on various polyesters (poly(butylene terephthalate), poly(ethylene terephthalate), and some of their blends), it appears that the positive temperature coefficient becomes higher when the blends are heated above the glass transition temperature of the polyester. Polyalkene melting induces a hysteresis effect between heating and cooling steps. Attempts to catalyse grafting through enhanced transesterification also promote polyester degradation and alter the morphologies of the blends.