玉米秸秆纤维素磷酸酯的制备及性能

Preparation and Performance of Corn Straw Cellulose Phosphate Ester

［目的］研究玉米秸秆纤维素磷酸酯的制备及性能。［方法］玉米秸秆为原料，尿素为催化剂，研究了玉米秸秆纤维素磷酸酯的最佳合成条件以及对含Cr6＋模拟废水的最佳吸附条件，并对样品进行了SEM表征。［结果］最佳合成条件：5.0 g玉米秸秆粉末中加入30 ml w（NaOH）=20%水溶液碱化40 min，水洗至中性得到碱纤维；5.0 g碱纤维用w（H3PO4）=20%水溶液40 ml浸泡9 h，过滤，滤饼中加入5 ml w（H3PO4）=85%水溶液，0.5 g尿素、20 ml甲苯作溶剂，在50 ℃下反应40 min，得产品。吸附的最佳条件：pH为3~5，投加量为1.0 g/100 ml，吸附时间为24 h，吸附效果最佳，去除率达96%。利用SEM表征了玉米秸秆改性前后表面结构，结果显示，改性后物体表面变得蓬松粗糙，出现卷曲褶皱，比表面积增大，有利对金属离子的吸附。［结论］该研究可为废弃物的多元化利用和废水处理提供新思路。

[ Objective ] The research aimed to study the preparation and performance of corn straw cellulose phosphate ester. [ Method ] Corn straw as the material, urea as catalyst, the optimal synthesis condition of corn straw cellulose phosphate ester and its optimal adsorption condi- tion to the simulated wastewater containing Cr6＋ were studied. [ Result] Corn straw powder （5.0 g） reacted with 30 ml of w（NaOH） =20% aqueous solution for 40 min, and alkali cellulose was obtained after washed to neutral. The prepared alkali cellulose （5.0 g） was pre-expand- ed with 40 ml of w （ H3 PO4 ） = 20% aqueous solution for 9 h, and then was filtered. In the filter cake, 5 ml of w （ H3 PO4 ） = 85 % aqueous solution, 0. 5 g urea and 20 ml of methylbenzene were added at 50 ℃ for 40 min to give the final product. When pH was between 3 and 5, the dosage of corn straw cellulose phosphate ester was 1.0 g/100 ml, and adsorption time was 24 h, adsorption effect was the best, and removal rate reached 96%. The microscopic structure of the adsorbent before and after modification was compared. The results showed that the modified surface becomes fluffy, coarse and curly, and specific surface area increases, which is favorable for adsorption of metal ion. [ Conclusion] The research could provide new thinking for diversified utilization of waste and wastewater treatment.