HEAT OF IMMERSION CALORIMETRY STUDIES OF CARBON-BLACKS

Immersional heats of carbon blacks into n-heptane and water have been investigated. It has been found that the dispersion component of the c arbon black surface free energy (gamma(s)(d)) calculated from heat of immersion data slightly decreases with the surface oxygen concentratio n, which is suggested to be caused by the partial perturbation of the graphitic structure on the carbon black surface. gamma(s)(d) was also calculated from the nitrogen adsorption data and compared with that fr om heat of immersion data. The heat of immersion in water increases wi th the carbon black surface oxygen concentration. The ozone oxidation of the carbon black has been found to improve the filled-rubber proper ties for a polar rubber (nitrile butadiene rubber), but to decrease th e properties for a non-polar rubber (natural rubber).