Crosslinked low density polyethylene filled with silica—I. the effect of filler on crosslinking

Abstract

Mixtures of low density polyethylene with various types of silica were investigated. The polymer matrix was crosslinked by initiation with peroxides. Four grades of silica were characterized by different methods. The presence of SiO 2 was found to lead to the formation of bound polymer, its proportion depending on the surface area of the filler. On the other hand, the parameters of the polymer-filler interaction determined from equilibrium swelling data for crosslinked mixtures do not correspond to the filler surface area. The crosslinking process in polyethylene, when initiated by peroxide, is affected by the presence of the filler. Both physical (adsorption of the peroxide) and chemical (chemical nature of the filler) effects are important from this point of view.