CHARACTERIZATION OF SURFACE-ENERGY OF CARBON-BLACK SURFACES AND RELATIONSHIP TO ELASTOMER REINFORCEMENT

The surface activity of carbon blacks which dominates their reinforcing properties in elastomeric materials has not been clearly defined up to now in terms of a quantitative physical or chemical characteristic. In an attempt to describe the surface physical chemical characteristics of carbon blacks as completely as possible a variety of physical and chemical investigation methods was applied to a series of carbon blacks encompassing the range ot industrially applied production-grade carbon blacks. These test methods for carbon black were nitrogen-, CTAB-, DBP-adsorption, "tint" value, transmittance of toluene extract, hydrogen- and oxygen-content, wide-angle X-ray scattering (WAXS) for the elimination of crystallographic data, inverse gas chromatography and microgravimetric determination of adsorption isotherms; the carbon black filled compounds were characterized by carbon black dispersion, Mooney viscosity, vulcameter data, modulus, ultimate properties and finally dynamic mechanical behaviour. There is obviously evidence confirming the fact that among all received property parameters the apparent surface energy determined by inverse gaseous chromatography correlates best with the various mechanical properties of the vulcanizates.