Specific Surface Area

The reinforcing effect of white carbon black is primarily influenced by its specific surface area. In general, as the specific surface area increases, the strength properties of rubber products tend to improve. However, this may be accompanied by a reduction in resilience, tear strength, and wear resistance. Additionally, higher specific surface areas can lead to challenges in dispersion during mixing, increased heat generation, higher Mooney viscosity of rubber materials, and a higher risk of scorching. Therefore, the specific surface area requirements vary depending on the formulation, intended use, and the desired impact on the physical and mechanical properties of vulcanized rubber.

Oil Absorption Value

The oil absorption value indicates the degree of structure within white carbon black, with higher values indicating a lower degree of structure. In general, rubber vulcanizates with high oil absorption values tend to exhibit higher tensile strength and hardness, but lower elongation and wear resistance.

Surface Hydroxyl Group Content

At 900°C, the presence of surface hydroxyl groups is measured as a loss on ignition. Excessive surface hydroxyl groups can lead to brittleness in rubber composites and impact material structure. Additionally, surface hydroxyl groups have a strong affinity for accelerators, which can prolong the curing time.

pH Value

The pH value of white carbon black is typically around 7. An increase in pH value (reduced acidity) generally results in a faster vulcanization speed of rubber compounds.

Soluble Salt Content

Lower soluble salt content is generally preferred. However, reducing the soluble salt content can significantly increase production costs.