| PAN fiber production is a critical step in carbon fiber production process. Many ofdeficiencies of the PAN fiber will directly inherit to carbon fiber. Research spinningprocess parameters affected the performance of the PAN fiber is conducive to theimprovement of industrial production, and therefore has great significance.In this thesis, solution polymerization was adopted to prepare PAN spinningsolution. We present a new spinning method for preparing polyacrylonitrile(PAN)precursor fiber. On the basis of the dry-jet wet spinning method further expand the airlayer height to5~50cm. The as-spun fibers got a high drawn ratio and were partlyoriented. Duo to the combined effect of the orientation and crystallization the as-spunfiber solidified. In the case of the other conditions unchanged, we change the spinningprocess parameters. Spinning process parameters affecting the performance of the PANfiber were studied by Scanning Electron Microscopy (SEM), X-ray diffraction andsingle fiber tensile test. By determining the degree of crystallinity of the PAN precursorfibers under different conditions, we found that whether in the no coagulation bathcondition or in the coagulation bath condition, the degree of crystallinity of the PANprecursor fiber is increased with the increase of the speed of take-up bobbin and airlayer height, reduced with the increase of injection rate. Though the analysis of themechanical properties of the PAN precursor fiber, we found that the tensile strength andinitial modulus was increased with the increase of the speed of take-up bobbin and airlayer height, reduced with the increase of injection rate. By contrasting the mechanicalproperties of PAN precursor fibers under conditions of coagulation bath and nocoagulation bath, we found that in the same speed of take-up bobbin, injection rate andair layer height the mechanical properties of PAN fiber under conditions of no coagulation bath are superior to that under conditions of coagulation bath. |
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