Influence of chemical treatments on the surface properties of carbon blacks and on the thermal stability of carbon black/rubber composites

In this work, the effect of chemical treatment of carbon black on the thermal stability, including initial decomposition temperature (IDT), temperature of maximum rate of weight loss (T_max), integral procedural decomposition temperature (IPDT), decomposition temperature range, and decomposition activation energy (E_a) had been studied in terms of dynamic TGA. The pH, acid and base values, BET's and BJH's specific surface areas, and TEM analysis were also studied for the surface property changes before and after chemical treatments. As an experimental result, the chemical treatments based on acid and base reactions led to a significant physical change of carbon black surfaces. Especially the thermal stability of carbon black/rubber composites was greatly depended on the specific surface areas of the carbon blacks. The activation energy obtained from the Horowitz-Metzger equation for the decomposition rate decreased with increasing the thermooxidation of acidic surface treatment. This was due to the fast decomposition rate of decomposition temperature range of the acidified carbon black.