干喷湿纺碳纤维原丝制备过程中凝固浴条件对初生纤维结构的影响OA

Polyacrylonitrile(PAN)-based carbon fibers were widely used in aerospace,automotive manufacturing,and other fields due to their high tensile strength and high elastic modulus.However,defect structures formed during the preparation process led to decreased mechanical properties of the final carbon fibers.Fiber coagulation molding,as the first step in carbon fiber preparation,exerted a significant influence on fiber structure formation.In this study,PAN was spun using the dry-jet wet spinning process,and the bidirectional diffusion rate during fiber coagulation molding was regulated by adjusting the coagulation bath[dimethyl sulfoxide(DMSO)]temperature and concentration to investigate the influence of coagulation bath conditions on the structure of nascent fibers.Scanning electron microscopy,swelling degree,DMSO residue,and X-ray diffraction(XRD)tests were conducted.The results showed that when the coagulation bath temperature was 10℃and the coagulation bath mass fraction was 30%,the obtained nascent fibers exhibited a uniform circular cross-section with the lowest porosity,minimal DMSO residue,and the highest crystallinity,which was more favorable for the preparation of high-performance PAN precursor fibers.