Influence of electron-beam irradiation on thermal stabilization process of polyacrylonitrile fibers

In this work, we prepared polyacrylonitrile (PAN)-based fibers treated with different doses of electron (E)-beam irradiation during the oxidative stabilization process to investigate the effect on their thermal behaviors and molecular structures. FT-IR and UV-vis absorption spectra of the E-beam irradiated PAN fibers show varying conjugation and transformation of C. N to C. N groups as a function of the dose. The thermal properties were characterized using differential scanning calorimetry and thermogravimetric analysis. E-beam irradiation lowers the onset temperature, extends the exothermic reaction, and improves the thermal stabilization. From these results, it is concluded that E-beam irradiation improves the thermal properties of PAN fibers as a result of cyclization of PAN molecules.