Strategies for the production of PAN-Based carbon fibers with high tensile strength

Carbon fibers (CFs) have been considered as a next-generation material in high-performance applications such as aerospace, defense, sporting goods, wind energy, automobiles, electronics, and civil engineering industries due to their superior mechanical properties including high tensile strength and modulus and characteristics such as low density, good corrosion and low impact resistance, low coefficient of thermal expansion, and high electric conductivity. In this paper, we introduced the brief overview of the most widely produced and used polyacrylonitrile(PAN)-based CFs. In particular, the studies on developing high performance CFs by theoretical and experimental approaches were presented. Theoretical tensile strength of CFs can be ideally up to 100 GPa with the perfectly developed graphitic structure and its orientation along fiber direction. However, commercially available CFs reveal only tensile strength of 7 GPa because of the existing defects, misordered carbon crystals, and turbostratic structure. Those originate from manufacturing processes such as spinning, stabilization, and carbonization, which generate significant morphological and structural defects in both exterior and interior of CFs. The review covered the research on parameters related with the tensile properties and optimizing processes to increase the tensile strength of PAN-based CFs.