近临界水中蔗渣微晶纤维素的制备

Preparation of Sugarcane Bagasse Microcrystaline Cellulose in Near-critical Water

[目的]在近临界水中制备蔗渣微晶纤维素,探索反应条件对产品聚合度的影响。[方法]以蔗渣纤维素为起始原料在近临界水中清洁制备蔗渣微晶纤维素,通过对反应条件的考察得到反应规律及最佳的工艺条件,用FT-IR、XRD分析产品的结构及结晶度。[结果]在近临界水中清洁制备蔗渣微晶纤维素的较优工艺条件为:液固比40:1 ml/g,反应温度230℃,反应初压力2 MPa,反应时间50min。溶解温度、溶解时间对蔗渣纤维素的降解影响较大,而初始压力、液固比的影响相对较小,蔗渣纤维素在降解过程中并未发生晶型的转变,且降解首先发生在纤维素的非晶区。[结论]通过近临界水法可成功清洁制备出蔗渣微晶纤维素。

[ Objective] To prepare the sugarcane bagasse microcrystalline cellulose （SBMC） in near-crltical water, and explore the effects of re- action conditions on the degree of polymerization（DP） of product. [ Method] With sugarcane bagasse cellulose as starting materials ,the SBMC was prepared. The reaction rule and the best process conditions were obtained by the investigation of reaction conditions, and the structure and degree of crystallinity were analyzed by FF-IR and XRD ,respectively. [ Result] The best conditions to prepare the SBMC in near-critical water were 40 ： 1 ml/g of liquid-solid ratio,230℃ of reaction temperature,2 MPa of reaction pressure and 50 min of reaction time. The effect of initial pressure and liquid-solid ratio on the DP of SBMC was less obviously than that of the reaction temperature and time. The crystal form of SBMC didn＇ t change during the degradation process and the amorphous region of SBC was damaged first. [ Conclusion] The SBMC was successfully prepared by near-critical water.