纤维素经液氨预处理对其结构和晶型的影响

棉短绒纤维素在室温和工1.03MPn压力下用无水液氢进行预处理，并经蒸发除去大部分氨，研究液氮处理前后纤维素微细结构和结晶形态的变化，讨论氛对纤维素的作用机理。结果表明，液氮处理后纤维素的侧序分布、结晶度、微晶尺寸、晶格形态都发生深刻的变化。X-射线结晶度下降21％，微晶横向尺寸减少20％-40％，晶格由纤维素I转化为纤维素I。纤维素结构中较高序态区向低序和无序部分转移，这种物理结构的变化将增进纤维素的可及度，提高纤维素在制备行生物时的反应性。

The effect of treatment of cellulose with liquid anhydrous ammonia on the structure and lattice form

The cotton linters and dissolving cotton pulp were pretreated by liquid anhy-drous ammonia (L-NH,) under a pressure of 1. O3MPa at 25C and then the ammonia e-vaporated under ambienf conditions. The structure changes of cellulose have been inves-tigated. The action mechanism of ammonia on cellulose was also discussed. The resultsshowed that after the treatment of cellulose with L-NH3, the lateral order distribution,crystallinity, crystallite size and lattice form of cellulose were dramatically changed. TheX-ray crystallinity decreased by 21%, lateral dimension of crystallite decreased by 2O%~40%,the lattice form converted from cellulose I to cellulose' and the extent of c0n-version was up to 9O% in 18Ominutes treatment. The L-NH, treatment also caused atransition from high order region to lower order and disorder fractions. This changedphysical structure will improve the accessibility of cellulose and the reactivity of cellu-lose in derivative formation.