Enhancing spinnability and properties of carbon fibers through modification of isotropic coal tar pitch precursor

Producing general-purpose carbon fibers (GPCFs) with excellent properties using an economical raw material such as coal tar pitch (CTP) holds significant importance. To synthesize carbon fibers, the spinnability of precursor material plays an important role. However, the CTP impedes flowability during the spinning process due to possessing high molecular weight complex aromatic structures. To address this limitation, CTP was blended with varying proportions of petroleum pitch (5, 10 and 20 %) and spinnability and flow behavior were analyzed using Rheology measurements. The distinct constitutional properties of petroleum pitch also contributed to alterations in both the stabilization and carbonization processes. Carbon fibers produced from 10PP showed the highest tensile strength and modulus of -784 MPa and -47 GPa, respectively. The impact of oxidative and carbonization treatments on the resultant microstructural and mechanical properties of carbon fibers was thoroughly examined using various techniques such as FTIR, XPS, XRD, SEM, Raman and UTM. The results showed that the composition of petroleum pitch influenced the stabilization of fibers which eventually affected the carbonization process and resultant properties of carbon fibers. This study offers an understanding of the connection between the precursor 's composition, stabilization conditions, and mechanical properties of the resultant carbon fibers.