Photoinitiated crosslinking of low density polyethylene I: Reaction and kinetics

The kinetics of the reaction in photocrosslinking of the low density polyethylene-benzophenone-triallyl cyanurate (LDPE-BP-TAC) system was studied by theoretically deriving a kinetic equation and comparing it with the results from crosslinking, extraction and swelling experiments. It was found that the rate of crosslinking is proportional to the square of light intensity. The roles of the crosslinker (TAC) were to capture the excited initiators efficiently to form free radicals and to act as a carrier of the active radicals. The ratio of degradation/ crosslinking was extrapolated to be around 0.28, and compared with 0.44 in the γ-irradiation process for the same material.