Carbon black acts as a reinforcing filler in tires and other rubber products. In other materials such as plastics, paints, and inks, carbon black is used as a color pigment or as filler to achieve electric conductivity.
Carbon black, produced by large scale industrial processes, is chemically and physically distinct from soot and black carbon, mostly found in soils and as pollutants in the atmosphere. Carbon black results from the incomplete combustion of heavy petroleum products and contains more than 97% elemental carbon. On the contrary, typically less than 60% of the total particle mass of soot or black carbon is composed of carbon, depending on the source and characteristics of the particles (shape, size, and heterogeneity). Carbon black reacts more quickly in chemical processes and gives rubber compounds heat dissipation capabilities.
The carbon black content can make up to 30% of the weight of a tire and helps tires as well as polypropylene pipes to last longer by maintaining the physical and chemical properties. It also raises the modulus of elasticity of a rubber by several factors. Due to its good electro-conducting and anti-static behavior, it can be used in e.g., electronics, vehicle gas caps, etc.
The carbon black content can be determined by thermogravimetric analysis (TGA).