Abstract
Electrical properties of electron beam crosslinked thermoplastic elastomeric films from low density polyethylene (LDPE) and ethylene vinyl acetate (EVA), containing 45% vinyl acetate, have been evaluated over a range of radiation doses (20 - 500 kGy), concentration levels of ditrimethylol propane tetraacrylate (DTMPTA) and blend proportions. Compared to the unirradiated samples, the permittivity and the dielectric loss factor decrease for the samples treated to a certain dose level beyond which there is a substantial increase. Volume resistivity and dielectric strength properties support the above observations. Variation of electrical properties with DTMPTA levels at a constant radiation dose clearly indicates the plasticising effect of the monomer, apart from its function as an aid to crosslinking. Both the permittivity and the dielectric loss factor increase with an increase in the EVA content of the blends as a result of which the electrical insulating properties of the blends decrease.