Preparation of Viscose Fibers by Treatment of Wood Pulp Using Electron Beam Irradiation

The conventional process for the production of viscose fibers in reducing the degree of polymerization of cellulose in the stage of ageing is to use alkaline solution of caustic soda and high concentrations of carbon disulfide over a long period of time. In this study, attempts have been made to treat wood pulp by electron beam irradiation so to reduce the degree of polymerization of cellulose. In such cases, the irradiated material may be dissolved in lower alkaline and carbon disulfide concentrations. Thus, treatment by electron irradiation may shorten the manufacturing process, more control on the degree of polymerization and a significant reduction in the consumption of chemicals and at the end to reduce environmental pollution. For comparison, the samples were prepared by conventional processing methods practiced in industry and electron beam treatment with irradiation dose of 5, 10 and 15 kGy. The prepared samples were characterized by water and dye absorption tests, solubility tests, Fourier transform infrared(FTIR) spectroscopy, scanning electron microscopy )SEM(, differential scanning calorimeter (DSC) and tensile properties. The results indicated that, an irradiated sample with 15 kGy dose exhibits maximum solubility, moisture and dye uptake. SEM results indicated a striated structure in the longitudinal and regular structural fibers and ridged cross sections. The results of DSC indicated the highest enthalpy of vaporization in the irradiated sample with 15 kGy dose that was in agreement with the results of water and dye absorptions. A high degradation temperature of the irradiated sample with 15 kGy dose revealed its high thermal stability. However, the irradiated sample with 15 kGy dose displayed maximum tensile strength but a decrease in 10% compared to a sample prepared by conventional process.