Modification of Carbon Black with Ionizing Radiations

It is well-known that the reinforcing properties of carbon blacks used as active fillers for rubber depend to a considerable extent upon the adsorption properties of the surface of the carbon black particles. The presence on this surface of atoms and groups of polar or apolar character chemically bound with it, the surface relief and the presence of atoms with unsatisfied valencies in the hydrocarbon framework of the elementary crystallites determine the specific adsorption properties of carbon black of various types. In the present investigation we demonstrate the possibility of modifying the surface of the carbon blacks by the action of ionizing irradiation and by the radiochemical “sewing-up” of various compounds on their surface. Such modified carbon blacks have a considerable influence upon the physico-chemical properties of the resulting vulcanizates, which may make is possible to create new materials. The investigation was devoted to: (1) Ukhta thermal black—a typical representative of the soft semireinforcing blacks (practically not oxidized) ; (2) channel black from the same works—a hard active black, having a markedly oxidized surface, capable of irreversible interaction with the surface of the rubber and with the compounding ingredients.