Carbon Black Content
Carbon black (graphite) is one of the most popular plastic additives not only because it is a cheap source of black pigment but also because it offers excellent mechanical properties and resistance to oxidation-weathering. Therefore, assessing the level of carbon black content is necessary in order to keep control of the plastic properties.
ASTM D1603 and ISO 6964 present standard methods for assessing the carbon black content in olefin and PE pipes materials, respectively.
More precisely, the test methods describe the determination of the carbon black content in polyethylene, polypropylene, and polybutylene plastic. The apparatus used is a tube furnace with a combustion boat placed inside.
Initially, the material is heated at 550 °C to burn off the polymer its mass it recorded before and after this process. Finally, the residue is heated at 900 °C until all the carbon black material burns off, then it is cooled and weighed.
