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

ABSTRACT 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.