carbon black (also known as carbon black) is an amorphous carbon. Light, loose and extremely fine black powder with a very large specific surface area ranging from 1-3m2/g is the product of incomplete combustion or thermal decomposition of organic matter (natural gas, heavy oil, fuel oil, etc.) under the condition of insufficient air. Specific gravity of 1.8-2.1 is called "gas black" if it is made of natural gas, "lamp black" if it is made of oil, and "acetylene black" if it is made of acetylene. In addition, there are "tank black" and "furnace black". According to the properties of carbon black, there are "reinforced carbon black", "conductive carbon black" and "wear-resistant carbon black". It can be used as a black dye, used to make China ink stick, ink, paint, etc., and also used as a reinforcing agent for rubber. According to records, China is one of the earliest countries to produce carbon black in the world.

different production processes of carbon black have different chemical properties on the surface. The true surface area of most carbon blacks is larger than the geometric surface area calculated from the particle size. This is because there are many micropores on the surface of carbon black, especially carbon black with particle size less than 25nm.

According to the analysis, groups such as phenolic group, quinone group and carboxyl group can be detected on the surface of carbon black, and the concentration of these acidic groups is particularly high on the surface of gas black and oxidation furnace black. Pyranone structure can be detected in furnace black, which determines the alkaline properties of furnace black. The content of volatile matter can judge the concentration of surface functional groups, and also measure the polarity of carbon black. In addition, due to the large surface area of carbon black, it is easy to absorb moisture in volatile environment, so special attention should be paid to moisture absorption during transportation, storage and use of carbon black.

most of them are about the geometric study of contact between conductive particles. According to this theory, the greater the carbon black filling amount, the greater the density of carbon black particles or carbon black particle aggregates in dispersed state, the smaller the average distance between particles, the higher the probability of mutual contact, and the more conductive paths formed by carbon black particles or carbon black particle aggregates. The greater the polarity of the * * * mixed system composed of polymers with different polarities and carbon black, the greater the critical volume fraction of carbon black, which means that the conductivity of the system decreases, because the surface of carbon black contains strong polar groups, and the matrix is polar, which enhances the effect. At this time, the strength increases, but it hinders the agglutination of conductive particles themselves, resulting in poor conductivity. However, in the * * * mixed system composed of multi-component matrix resin and carbon black, due to the different polarities of different matrices, the filled carbon black will produce segregation phenomenon. At this time, the conductivity depends on the concentration and distribution of carbon black particles in the segregation phase, and also on the proportion of high polymers in the segregation phase.