Ferrocenecarboxaldehyde modified terephthalaldehyde-phenolic resin: A comprehensive study on the synthesis, curing behavior, and pyrolysis process

To meet the demand for high performance carbon-based materials, catalytic graphitization particles are widely used to improve the thermal stability and char yields of conventional phenolic resins. The direct addition of inorganic particles may cause significant phase separation and reduce the crosslinking density of phenolic resins. In the study, a non-hazardous aromatic dialdehyde, terephthalaldehyde (TPA), was utilized to synthesize a formaldehyde-free phenolic resin (PTPA). A high char yield ferrocenecarboxaldehyde modified terephthalaldehyde-phenolic resin (Fc-PTPA) with a value of 76.0% at 800 °C was obtained by co-curing ferrocenecarboxaldehyde (Fc) and PTPA. The curing process of Fc-PTPA and the carbide structural evolution during pyrolysis were studied. The results show that Fc could act in the second stage of curing which led to an increase in the crosslinking density of resin. The generated Fe3C during the pyrolysis of Fc-PTPA contributed to form a more ordered carbide structure which was an important reason for the improvement in the thermal properties and char yields.