Structural features and electrical properties of carbon fibers manufactured from poly(2-cyano-1,4-phenylene terephthalamide) precursor as a new para-aramid

We have manufactured carbon fibers (CFs) from poly(2-cyano-1,4-phenylene terephthalamide) (cyPPTA) precursor as a new para-aramid via iodination, stabilization and carbonization, and have investigated their structural features and electrical properties as a function of the carbonization temperature. For the purpose, cyPPTA is synthesized by phosphorylation-based polycondensation reaction and its pristine fibers with 8-10 μm diameter are fabricated by wet-spinning process. FT-IR and EDS spectra show that the iodination is carried out successfully by forming complexes of polyiodides in the pristine cyPPTA fibers. Accordingly, the residue at 800 °C for the iodinated cyPPTA fiber is found to be higher than that of the pristine fiber. In addition, the thermal stability of iodinated and stabilized cyPPTA fibers is far higher than those of pristine and stabilized fibers. Raman spectra reveal that cyPPTA-based CFs, which are iodinated, stabilized at 400 °C, and carbonized at 700-1000 °C, exhibit the formation of a typical graphitic structure. In addition, high electrical conductivity of ~45.5 S/cm is achieved for the cyPPTA-based CF carbonized at 1000 °C.