Effects of radiation pretreatments on the rubber adsorption power and reinforcing properties of fillers in rubber compounds

Radiation damage to fillers such as carbon black, graphite and silica induced by high doses of gamma -radiation or neutrons dramatically increases their ability to adsorb rubber irreversibly. In fact, the 'bound rubber', ie the amount of non-extractable rubber which remains irreversibly linked to the filler matrix, increases dramatically in radiation-treated fillers. The increased adsorption power of radiation-damaged filters has been attributed to the formation of a higher concentration of surface defects in the form of trapped free radicals, fullerene-like structures and other kinds of defects. The mechanical properties of rubber compounds filled with radiation-treated carbon blacks show a significant increase in their reinforcing effects, in line with the increased ability to form (bound rubber'. (C) 2001 Society of Chemical Industry.