How Surface Oxidation of Carbon Black Affects Electrical Conductivity
Sep 09, 2022
Under the condition of the same surface area and structure, the conductivity of oxidized carbon black is weaker than that of unoxidized carbon black. Since the surface has greater insulating properties after adsorbing oxygen-containing groups, the electrical conductivity is reduced.
blend of carbon black
Mixing carbon black is an important step in dispersing carbon black, which refers to the use of resin or solvent to wet the carbon black surface. Essentially it means displacement of the enclosed air and complete coverage of the aggregate surface to obtain a dispersible mixture that is easy to process.
Volatile content of carbon black
Volatile content is a measure of the amount of chemisorbed oxygen groups (expressed in percent weight loss) that will be released when the carbon black is heated to high temperatures. Values for volatile content do not include absorbed moisture. This has nothing to do with the content of volatiles in the traditional sense, which refers to the value of the content of absorbed organic compounds. Under heating conditions, the chemisorbed oxygen groups can be decomposed and disappeared by converting into gases, such as carbon dioxide and water.
How the physical form of carbon black affects the dispersion rate
Powdered carbon black or denser granular carbon black can be used directly. Granular carbon blacks are easier to handle and mix faster than powdered carbon blacks. However, granular carbon blacks are more difficult to disperse because the densification process increases the proximity of agglomerates, thereby increasing van der Waals forces that must be overcome during the dispersion process.
The structure of carbon black affects gloss
Due to the higher oil absorption, high-structure carbon blacks reduce the gloss of the finished product to a greater extent than low-structure carbon blacks.
Effect of Carbon Black Structure on Color Properties
Compared with the specific surface area, the structure of carbon black has little effect on the color, but the color of high-structure carbon black is weakened, and because of its better dispersion, the hue is bluer than that of carbon black with the same surface area.
