Surface energy characterization of modified carbon blacks and its relationship to composites tearing properties

The effects of three types of chemical treatments, i.e. as polar acidic, polar basic, and nonpolar oxidations, on virgin carbon blacks have been studied in terms of pH, acid-base surface values, specific surface area, X-ray diffraction analysis, and surface free energy. The acidic chemical treatment leads to significant changes in surface and adsorption properties, surface free energy, and microstructures. The increased acidic surface functional groups on carbon blacks result from reaction between the basic carbon and the acidic chemical solution. Also, based on the determination of surface free energy from contact angle measurements, a good correlation between the London dispersive component or apolar (γ_S^d) of surface free energy and specific surface area (S_BET) (or crystalline size along the c-axis, L_C) is shown in this work. Particularly, it is found that the γ_S^d of the carbon blacks studied is highly correlated with the mechanical tearing test results based on hydrocarbon rubber compound composites.