ELECTRON-BEAM (EB) CROSS-LINKING OF PVC INSULATION IN PRESENCE OF SENSITIZER ADDITIVES

Radiation crosslinking of flexible PVC (polyvinyl chloride) was studie d with the aim of developing a suitable insulation to be used in vario us electrical appliances, PVC insulation material containing three dif ferent sensitisers like tetra-ethyl glycol dimethacrylate, ethylene gl ycol dimethacrylate and trimethylol propane trimethacrylate were irrad iated with electron beam radiation up to 150 kGy dose and the effect o f sensitiser on the radiation cross-linking has been investigated. Bes ides this, thermal stability of insulation having stabilisers (such as tri-basic lead sulphate and di-basic lead phthalate) has also been st udied. Tensile strength, volume resistivity, and decomposition tempera ture, have been found to be improved under irradiation, whereas long t erm aging characteristics at elevated temperature deteriorate. However glass transition temperature does not show significant change up to 1 00 kGy dose. It was also observed that TMPTM (tri-methylol propane tri -methacrylate) is a better cross linking agent, whereas DBLP (di-basic lead phthalate) appears to contribute towards better thermal stabilit y.