Abstract:

The crop straw resources are very plentiful in natureIn this paper the crop straws were used as raw material for acetylation after activation with unpolluted steam explosionAccording to different solubilities of acetylated products, cellulose acetate were prepared by solvent extractionThe results indicated that the reaction activity increased dramatically after steam explosion, and the best reaction condition was that the straws were acetylated at 123℃ for 2 h in the presence of 7% catalystAfter pretreatment of steam exploded straw with a neutral detergent, good result of acetylation for crop straw could be obtainedThe acetylationconversion and mass increase were enhanced most for wheat strawThe degree of polymerization and substitution of cellulose acetate achieved were over 120 and 2.80 respectivelyThe product was characterized with IR and 1H NMRCompared with high α-cellulose as raw material, not only the cost was very low ,but also the process was simplified greatly.

摘要：

农作物秸秆是自然界中数量极大的可再生资源，本研究以农作物秸秆为反应原料，采用无污染蒸汽爆破技术活化预处理，然后进行乙酰化反应，通过溶剂萃取分离并制备出高附加值的醋酸纤维素。实验结果表明：秸秆汽爆后明显增加了反应活性，制备醋酸纤维素的适宜条件是123℃，2 h，催化剂用量为7％，汽爆秸秆中性洗涤剂处理后的乙酰化结果效果最好，不同汽爆秸秆中小麦秸秆乙酰化效果最佳，优化实验条件下，秸秆醋酸纤维素聚合度均在120以上，取代度2.80以上，并且用红外图谱、1H NMR进行了表征。与目前工业上采用α-纤维素含量较高的高级浆为反应原料相比，不仅原料和预处理成本大大降低，而且工艺流程简单。