Christian-Doppler-Laboratory, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Straße 24, A-3430 Tulln an der Donau, Austria.
Carbohydr Polym. 2013 Jan 30;92(1):921-7. doi: 10.1016/j.carbpol.2012.09.039. Epub 2012 Sep 28.
The sonochemical degradation of cellulose by a 24-kHz ultrasound probe system and the oxidative modification of cellulose upon sonication were studied. Both aqueous cellulose suspension (heterogeneous system) as well as cellulose solutions in N,N-dimethylacetamide/LiCl (homogeneous system) were used. In both cases, a significant reduction in the degree of polymerization was observed. The rate of the degradation process was dependent on the degree of polymerization of the starting material, temperature, cellulose amount in suspension, cellulose concentration in solution, and the pH value of the aqueous suspension. In solution, the degradation process was accompanied by cellulose oxidation as seen in the introduction of carbonyl groups. The introduction of carbonyl groups could be shown to occur close to chain ends. Sonochemical degradation of cellulose is a very efficient non-classical method in accordance with "green chemistry" concepts.
研究了 24kHz 超声探针系统对纤维素的超声降解作用，以及超声作用下纤维素的氧化修饰。分别使用了水基纤维素悬浮液（多相体系）和 N，N-二甲基乙酰胺/氯化锂中的纤维素溶液（均相体系）。在这两种情况下，均观察到聚合度显著降低。降解过程的速率取决于起始材料的聚合度、温度、悬浮液中的纤维素量、溶液中的纤维素浓度以及水悬浮液的 pH 值。在溶液中，降解过程伴随着纤维素氧化，表现为羰基的引入。可以看出，羰基的引入发生在链末端附近。根据“绿色化学”的概念，纤维素的超声降解是一种非常有效的非经典方法。
