棉纤维素闪爆预处理对NC性能影响分析

Effect of pretreatment of cotton cellulose by steam explosion on properties of nitrocellulose

采用高压蒸汽闪爆技术对天然棉纤维素进行预改性处理,以硝硫混酸作为硝化剂,对改性后的纤维素进行硝化,并对硝化产物的含氮量、硝酸酯基分布的均匀性以及在有机溶剂中的溶解度进行测试。结果表明:与未经改性处理的纤维素制得的产物相比,利用闪爆改性后的纤维素制得的硝化纤维素含氮量有一定的提高,氮量分布的均匀性有较大程度的提高。但当闪爆压力超过一定的值时,会导致纤维原料发生类酸解和机械降解,对硝化产物溶解度有较大的影响。

Cotton cellulose was pre-treaded by high-pressure high-temperature steam; the regenerated cellulose after such pre-treatment was nitrified in sulphonitric medium. Analyses on nitrogen content of products, uniformity of nitrate group, and its solubility in organic solvents of nitrocellulose indicate that the nitrogen content of the products after pretreatment was improved than that in the product without such pretreatment, and that the uniformity of the N02 on the NC chains was enhanced. When steam pressure exceeds a certain value, polymerization of cotton cellulose is reduced because of like-acid degradation and machine breaking, which has an significant impact on NC solubility.