The characterization of polyacrylonitrile fibers stabilized by electron beam irradiation

This study investigates polyacrylonitile(PAN) fibers stabilized with various doses of electron beam irradiation (EBI) ability to produce carbon fibers. Feasibility was verified by FT-IR, the percent of gel fraction, density, DSC, XRD, and mechanical measurements. FT-IR spectra showed that the intensities of the stretching C??N bonds decreased at 2,244 cm^?1 with increasing EBI dose. This de crease was related to cyclization of nitrile groups during EBI-stabilization. The degree of cyclization was determined from the gel fraction and density tests. The gel content and density of PAN fibers stabilized by EBI increased with an increase in the EBI dose. Thermal properties were characterized by differential scanning calorimetry (DSC) and thermally activated reactions. DSC curves showed that EBI treatment influenced the quantity of released heat and the exothermic position at low temperature over a wide temperature range. The strongest diffraction peak from the PAN precursor fiber arose from the (100) plane; its stabilization index (SI) was evaluated by X-ray diffraction. The X-ray results showed that the peak intensity decreases gradually with increasing EBI dose. In addition, tensile strength decreased the EBI stabilization level.