Introduction to the Action Mechanism of Carbon Black in Rubber

Carbon black is a micron sized amorphous carbon particle obtained from incomplete combustion or pyrolysis of carbon containing substances. It is one of the most important fillers in the rubber industry and is widely used in rubber products such as tires, hoses, and tapes. Carbon black can not only improve the mechanical properties, wear resistance, aging resistance, and conductivity of rubber, but also reduce the cost and weight of rubber. So, how does carbon black play these roles in rubber? This article will introduce the mechanism of carbon black in rubber from the following aspects:
The reinforcing effect of carbon black
The strengthening effect of carbon black refers to the physical properties of rubber, such as strength, hardness, modulus, and wear resistance, which can be improved by carbon black, enabling rubber to have better load-bearing capacity and service life. The enhancement effect of carbon black mainly depends on the following factors:
Specific surface area of carbon black:
Specific surface area refers to the surface area of carbon black per unit mass or volume, which reflects the size and morphology of carbon black particles. Generally speaking, the larger the specific surface area, the smaller the carbon black particles, and the larger the contact area with rubber molecules, thereby increasing the friction and bonding force between rubber and carbon black, and improving the reinforcement effect of rubber.
The structure of carbon black:
Structure refers to the degree to which carbon black particles aggregate and form aggregates, reflecting the voids and pores between carbon black particles. Generally speaking, the higher the structure, the more voids and pores between carbon black particles, and the stronger the entanglement between rubber molecules, thereby increasing the friction and adhesion between rubber and carbon black, and improving the reinforcement effect of rubber.
Dispersion of carbon black:
Dispersion refers to the degree to which carbon black is uniformly distributed in the rubber matrix, which reflects the compatibility and flowability of carbon black with rubber during the mixing process. Generally speaking, the better the dispersibility, the finer, more uniform, and more stable dispersed phases formed by carbon black in rubber, allowing each carbon black particle to fully exert its reinforcing effect and improve the overall performance of the rubber.