Terpolymer of Acrylonitrile, Maleic Anhydride, and Itaconic Acid for Carbon Fiber Precursor: Effect of Comonomer Structure on the Processability of Polyacrylonitrile Copolymers

Polyacrylonitrile copolymers serve as important precursors for the preparation of high-performance carbon fibers (CFs). In this study, maleic anhydride (MAn) was employed to prepare P(AN-MAn-IA) terpolymer by solution polymerization with different feeding ratios of the monomers. The molecular structure, thermal properties, and crystallization properties of the polymers were characterized. Thermal analysis (differential scanning calorimetry [DSC]/thermogravimetric analysis [TGA]) indicates that MAn significantly enhances the stabilization of P(AN-MAn-IA) relative to PAN homopolymer, as evidenced by a reduced initiation temperature, a broader exothermic peak, and decreased activation energy. Rheometric analysis was conducted to investigate the rheological properties of PAN and P(AN-MAn-IA) copolymer solutions, with findings demonstrating that the introduction of MAn leads to an improvement in the spinnability of the solutions. The study verified the potential of P(AN-MAn-IA) as a precursor material for CFs.