Acetylene and specialty carbon blacks

What is acetylene carbon black?

Acetylene black is produced by the exothermic decomposition of acetylene. Therefore, it is very pure carbon black. It is the closest to graphite of all carbon blacks and is often used to provide electrical conductivity.

Acetylene black is a carbon black obtained by continuous pyrolysis of acetylene with a purity of more than 99% obtained by the decomposition and purification of by-product gas during the pyrolysis of calcium carbide or naphtha (crude gasoline). The inside of the reaction furnace was heated up to 800°C or higher, the starting temperature of acetylene decomposition, and then acetylene was introduced to start thermal decomposition. Since it is an exothermic reaction, the reaction can proceed automatically. In order to obtain stable quality, the reaction temperature should be kept around 1800 °C. The temperature in the furnace can be controlled by the water cooling jacket of the outer cylinder of the reaction furnace. Acetylene black is used as the negative electrode material of nickel-hydrogen battery together with the oxide separator and electrolyte. Compared with furnace carbon black, it has more developed crystallization and secondary structure, so its conductivity and liquid absorption are also better. Due to the small amount of impurities such as heavy metals, the loss caused by self-discharge is small, and it is mainly used for the negative electrode of nickel-hydrogen battery.

Acetylene black can be used in supercapacitors as conductors.

Physical and chemical properties:

The appearance is black very fine powder, the relative density is 1.95 (nitrogen replacement method). Apparent density 0.2 ~ O.3g/cm³. Average particle size 30 ~ 45nm. Specific surface area 55 ~ 70㎡/g. Iodine absorption value 60 ~ 80gI2/kg. The hydrogen content is less than 0.1%, and the oxygen content is 0.07% ~ 0.26%. The pH value is 5 ~ 7. The resistivity is extremely low, and it has excellent electrical conductivity, thermal conductivity and antistatic effect.

carbon black for special applications can endow products with carbon black with special performance requirements. Carbon black has a wide range of uses, in addition to rubber products, there are other uses, so it is divided into two types of carbon black for rubber and special carbon black. Special carbon black can be obtained by post-processing disposable carbon black. The post-treatment is mostly mechanical grinding, chemical vapor phase and liquid phase surface oxidation treatment. Oxidants include nitrogen oxide, ozone, oxygen, air, nitric acid, nitric acid, potassium permanganate, hypochlorous acid, etc., which can change the properties of the original carbon black to meet different requirements. Specialty carbon blacks are used in coloring, conductive materials such as paints, ink resins, black films, toners, films, magnetic tapes, optical discs, etc.