Preparation of High Wet-Strength Paper from Rice Straw Pulp by Treatment with ZnCl2 Aqueous Solution

In this research, laboratory sheets made from rice straw bleached chemical pulps were impregnated with a ZnCl2 aqueous solution to prepare high wet-strength paper, and the effects of the concentration of the ZnCl2 solution, impregnation temperature and period, and ethanol washing period were evaluated through single factor tests, The optimal conditions was determined to be 60%, 65 oC, 10 min, and 12 min, respectively. Under these conditions, the dry tensile and dry burst indices of the sheet prepared from the impregnated laboratory sheets doubled, and both the wet indices quadrupled as compared to those from untreated laboratory sheets. There were no significant changes in the cellulose crystal form and crystallinity. However, the paper surface morphology changed significantly.