Polyolefins as candidates for HVDC cable insulation materials

DC breakdown strength, DC conductivity and thermally stimulated current data are presented for two groups of polymers. One is polyetheylene (thermoplastic and crosslinked) and its copolymers, the other is polypropylene (iso- and syndiotactic) and its copolymers. Possibilities of increasing the breakdown strength and decreasing the charge accumulation tendencies are explored and inter-relations among the mentioned properties are looked for.