rom the dawn of civilization, carbon black has been a component of humankind's tool chest. Carbon black production methods and morphology have changed over the eons to become more efficient, less polluting, and higher performing in the markets that carbon black serves.
Carbon black is the oldest man-made nanoparticle. A rough description compares carbon black to an aciniform-type morphology, which resembles a bunch of grapes. The individual “grapes” are the primary particles and the entire bunch is referred to as the aggregate. The dimensions of the “grapes” are less than 10–300 nm and the dimension of the aggregate is 100–800 nm. The interstitial volume created by the grapes that are covalently bound to each other creates the advantageous interaction with polymer systems that can penetrate these void volumes.
If you take a second to look around the room you will notice that carbon black is everywhere. Anything that is black and plastic, anything that is printed in black color, and anything that is black and made out of rubber will have carbon black present. In plastic, carbon black imparts not only black color, but also provides electrical conductivity and some minor improvements in strength and toughness. The current amount of carbon black that is compounded into plastics is 800,000 tons per annum.
Carbon black is no new comer to the industrial work sector. Roman text from Vitrivius described the process in detail to produce an incomplete combustion product from the resin of pine trees. The resulting black powder would be mixed into gum Arabic for writing inks and also mixed with glue for mural paintings to be on display throughout the Roman cities of antiquity. Over the years, the processes to produce carbon black evolved to make a variety of other types of carbon black, including lampblack, thermal black, and a variety of other blacks from the carbon black family. From the days of the ancients to the mid-19th century, the common feedstock was aromatic oils, such as pine resin.
This article appeared in the May/June issue of Reinforced Plastics.