Why are there so many grades of carbon black?
The properties of carbon black (such as color, rubber strength or easy dispersibility) need to be customized to suit specific applications. The properties of carbon black can usually be controlled by changing its surface area and / or structure. Does carbon black absorb moisture?

Carbon black will absorb (adsorb) moisture until it reaches an equilibrium absorption value. This value is usually expressed in% by weight, so it will vary on carbon black grades depending on surface area and surface chemistry.

Is carbon black porous?
The traditional furnace black contains very few pores. In addition, any pores present are usually limited to the micropore range (<2 nm). Such pores can be quantified as the total micropore volume by nitrogen adsorption isotherm analysis.

Under what circumstances will carbon black decompose?
Usually, carbon black begins to decompose between 450 and 500 degrees Celsius in air or oxygen. Carbon black does not decompose in nitrogen at these temperatures. Carbon black is usually tested at 550 degrees Celsius.