Structure of PAN precursor in thermal-induced gel spinning

摘要

The thermal-induced gel spinning of polyacrylonitrile/dimethyl sulfoxide/water solutions were performed. The structure and performance of the PAN precursor fibers were characterized by mechanical properties testing, swelling capacity testing, scanning electron microscopy, and X-ray diffraction. The effects of the water content, polymer concentration, coagulation bath temperature, and draw ratio on the cross-sectional morphology, structure, and tensile properties are reported. The results show that 2% water content is optimal due to dispersed small pores found in the fibers' cross section. With the coagulating bath temperature decreased, the large pores in fibers also decreased. Large pores almost disappeared up to -9°C. The mechanical properties of the PAN fibers increased with the enhancement of PAN concentration, while the decrease of the coagulating bath temperature or water content would induce the improvement of the fibers' mechanical properties.