Effect of Tailoring Comonomer Feed time on Characteristics of Polyacrylonitrile Precursor Fiber

Abstract

Carbon fibers have gained significant attention due to their light weight (1.75-2.00 g/cm3), superior modulus (up to 900 GPa) and tensile strength (up to 7 GPa, (T1100, Toray, Japan)). Furthermore, they offer excellent thermal stability, electrical conductivity, and thermal conductivity, making them invaluable for cutting-edge applications in aerospace, automotive, smart devices, and recreational sports equipment. Commercial carbon fibers are derived from various organic precursors such as polyacrylonitrile (PAN), rayon and pitch, and their mechanical properties are depending on according to precursor fibers. PAN has been widely used as a precursor due to its high carbon yield (in the range of 50-60 %) and stable structure stability. PAN copolymers, including methacrylic acid (MAA) methyl acrylate (MA) and itaconic acid (IA), are favored as carbon fiber precursors that allows high thermal stability and carbonization yield. The properties of PAN precursor fibers are influenced by various factors, with the composition of the polymers playing a pivotal role. Different interactions between the functional groups of the monomers can trigger variations in the characteristics of PAN copolymers, making it possible to tailor these copolymers to our specific requirements. In this study, we synthesized tailored P(AN-MAA) copolymers by controlling the timing of comonomer addition. Subsequently, we prepared and analyzed to these copolymers to assess their impact on PAN precursor fibers. The PAN precursor fibers were prepared through the air-gap spinning process and the dry-drawing process. Our research focused on examining how controlling the timing of comonomer addition affected the morphology, mechanical properties, and microstructure of the precursor fibers. This study contributes to the design of characteristics to produce high-performance precursor fibers and, consequently, high-quality carbon fibers.