Carbonization chemistry of heating carbon composites containing novolac/furfuryl alcohol resins and carbon black or mesophase pitch as additives

Carbon composites containing novolac/furfuryl alcohol resins with hexamethylene tetramine (HMTA) asa crosslinker and carbon black or mesophase pitch as an additive, were heated to 1000 ◦C under Argonatmosphere. Carbonization chemistry was studied including the nitrogen-containing structures in thefinal carbons. The volatiles released during the heating were furfuryl, phenol-benzene species, methane,ethane and other small molecular species such as moisture, CO2, CO and ammonia. When carbon blackwas used as an additive in the composite, a considerable amount of furfuryl and phenolic species were“trapped” on the surface of carbon black particles, resulting in a higher carbon yield. Certain carbonizationreactions also occurred at lower temperatures, and the dimensional shrinkage was reduced as comparedto the resin-only system. On the other hand, the mesophase pitch additive formed homogeneous morphologieswith the resin binder, participated in the carbonization process of the resin binder and formedamorphous carbons with porous structures and dimensional expansion. Manipulating the compositionand variety of the additives could produce carbon composites with designed performance