木素的存在对纤维素水解反应性能及其产物结构的影响

对木素含量为0.9％—8.3％的速生杨硫酸盐浆进行了X—射线分析研究。利用多相水解方法测定了其反应性能。研究结果确定,浆中结晶纤维素含量取决于木素脱出程度并随着木素含量的降低而增加。木屑和浆中的纤维素结晶度相当高,而在脱木素过程中只呈微小变化。木素存在于多相水解反应过程中起着阻碍纤维素水解的作用,降低其反应速度常数。基于研究结果,提出了木素与纤维素结晶部分外表面联结的结论.并探讨了这种联结键的可能形式。

EFFECT OF LIGNIN PRESENCE IN PULP ON THE REACTIVITY OF CELLULOSE IN HYDROLYSIS AND STRUCTURE OF ITS PRODUCTS

Pulp of poplar wood obtained by sulfate cooking containing lignin in the amount of 0.9%—8.3% was studied by X—ray diffractometry. Method of heterogeneous hydrolysis was used for determining its reactivity. The content of the crystalline fraction in lignecellulose depends on the lignin removal and increases with the decrease of the lignin content. The degree of crystallinity of cellulose in sawdust and pulp is fairly high and changes sligtly with the lignin remvoal. Lignin plays a blocking role in heterogenous hydrolysis and decreases its rate constant. It is suggested that lignin is bonded to cellulose on the outer surfaces of the crystalline part of cellulose fibril. Some possible variants of these bonds are discussed.