Methods for producing high strength reinforced plastic materials

Reinforced plastic materials of superior physical properties are produced by bonding to the filler material a monomolecular layer of a coupling agent comprising a polymer of an unsaturated compound, for example polybutadiene, containing a suitable functional group. After compounding the treated filler material with a suitable polyolefine and extruding the compounded mixture, the extrudates are subjected to a suitable dose, e.g. 125 kGy, of gamma radiation. The compounded mixture preferably contains a crosslinking agent, for example triallyl cyanurate, to permit the use of a smaller radiation dose. Suitable functional groups in the polymer of the unsaturated compound are di- or trimethoxysilyl for silicious filler materials and carboxyl for calcuim carbonate filler material