Influence of electron beam pre-irradiation on the thermal behaviors of polyacrylonitrile

Thermal treatment of polyacrylonitrile pre-irradiated by electron beam was performed to investigate the radiation effects on thermally activated reactions. Thermal properties were characterized by differential scanning calorimetry and thermogravimetric analyses. Pre-irradiation lowers the onset temperature of reactions and alleviated the heat evolution process. Char yields (800 °C) of polyacrylonitrile increase significantly with increasing irradiation dose. FTIR was used to monitor the thermal reaction. The results reveal that the thermal reactions can be regulated by pre-irradiation dose. FTIR and UV-visible absorption spectra of pre-irradiation polyacrylonitrile illustrate the formation of -HCN-NCH- conjugation across the polymeric chains as a function of dose, which could improve the thermal behaviors of polyacrylonitrile.