Effect of dope extrusion rate on the formation and characterization of polyacrylonitrile nascent fibers during wet-spinning

Polyacrylonitrile nascent fibers were prepared via the wet-spinning technique and a dimethyl sulphoxide/H₂O coagulation bath system was adopted. The objective of this study was to investigate the influence of dope extrusion rates on formation and characterization of nascent fibers. Nine different dope extrusion rates were adopted when other technique parameters were kept steady. The surface morphology of nascent fibers was observed by field emission scanning electron microscopy. The results showed that the dope extrusion rates played significant effects on the cross-section structure, surface morphology, degree of crystallization, and sound velocity of the nascent fibers. With an increase of dope extrusion rate, the surface roughness increased, and the sound velocity had a point of inflexion. Moreover, the degree of crystallization had a maximum when the dope extrusion rate was 5.92 m/min.