PROCESS FOR PREPARING PAPER-BASED MATERIAL BY ULTRASONIC-ASSISTED IONIC LIQUID TREATMENT OF ECF BLEACHED KRAFT PULP

The present invention discloses a process for preparing a paper-based material by ultrasonic assisted ionic liquid treatment of ECF bleached kraft pulp， where ultrasonic-assisted ionic liquid pretreatment is performed on an unbleached kraft pulp， then the obtained kraft pulp is subjected to ECF bleaching. In view of a problem about low physical strength of bleached pulp caused by serious fiber degradation due to poor selectivity of oxygen delignification during the bleaching process， the present invention presents a process for ultrasonic-assisted ionic liquid pretreatment. In the process， physical cavitation of ultrasonic wave and chemical treatment effect of ionic liquid are used to loosen the pulp fiber structure to improve the swelling and fibrillation of the pulp fiber and allow an easy delignification during the bleaching process， thereby avoiding oxidative damage of fiber in the bleaching process. This can improve physical strength properties of hardwood paper-based materials as well as brightness thereof.