Effect of nitrification condition and cellulose prereatment on nitrogen content and its distribution uniformity of nitrocellulose

The effect of three factors involving nitrification coefficient, swelling and ultrosonic pretreatment of cellulose on the nitrogen content and its distribution uniformity of nitrocellulose were investigated by a testing instrument for nitrogen content and distribution uniformity of NC. The results show that the nitrogen content of NC increased with increasing nitrification coefficient; the nitrogen distribution value D_e were low when the nitrification coefficient was 40,50 and 80, while it significantly increased at 20 or 100; Swelling pretreatment of cotton cellulose via thiourea and urea aqueous solution did not affect the nitrogen content of NC, but it can narrow NC s nitrogen distribution; prolonging the ultrasonic treatment time of cotton cellulose within the studing scale resulted in an increase of nitrogen content of NC. The nitrogen distribution of NC became significantly wider and the moleculor weight decreased after 10 min or 30 min ultrasonic treatment, while the nitrogen distribution became slightly narrower comparing with that of untreatment when ultrasonic treatment time prolonged to 60min, and the molecular weight increased slightly.