CROSS-LINKING OF POLYETHYLENE BY DICUMYL PEROXIDE IN THE PRESENCE OF 2,4-DIPHENYL-4-METHY1-1-PENTENE

Crosslinkings of low density polyethylene, high density polyethylene, and ethylene propylene rubber were carried out using dicumyl peroxide as a crosslinking agent. The addition of 2,4-diphenyl-4-methyl-1-pente ne (alpha-methylstyrene dimer: MSD) as a coagent increased the scorch time at 145 degrees C as well as the crosslinking efficiency at 180 de grees C. The scorch inhibition mechanism is explained by the addition- fragmentation reaction between MSD and polymer radicals. A reaction me chanism for the production of highly crosslinked polymers is postulate d and discussed.