Nature of mechanoradical formation of substituted celluloses as studied by electron spin resonance
Nature of mechanoradical formation of substituted celluloses as studied by electron spin resonance
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DOI：
10.1248/cpb.52.339
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发表时间：
2004-03-01
影响因子：
1.7
通讯作者：
Kuzuya, M
中科院分区：
文献类型：
--
作者：
Sasai, Y;Yamauchi, Y;Kuzuya, M
基于电子自旋共振(ESR)研究了几种取代纤维素如羧甲基纤维素、甲壳素和壳聚糖的机械诱导自由基的形成，并与等离子体诱导的自由基进行了比较。室温ESR谱具有多组分特征，且具有不同的谱型。各取代多糖的机械力浓度在达到最大值后逐渐降低，并伴随着振动研磨过程中相对分子质量的降低。最耐人寻味的事实之一是，在等离子体辐射的情况下，组成自由基都是基于葡萄糖的自由基，尽管我们知道机械性自由基是由多糖的1，4-葡萄糖苷键断裂形成的。
Mechanically induced free radical (mechanoradical) formation of several substituted celluloses such as carboxylmethyl cellulose, chitin, and chitosan was studied based on electron-spin resonance (ESR) in comparison with those of plasma-induced radicals. Room temperature ESR spectra had multicomponent spectra and were different in pattern from each other. The mechanoradical concentration gradually decreased after reaching the maximum value in each substituted polysaccharide, accompanied by a decrease in molecular weight in the course of vibratory milling. One of the most intriguing facts is that the component radicals are all glucose-based radicals as in the case of plasma irradiation, although it is known that mechanoradicals are formed by 1,4-glucosidic bond cleavage of polysaccharides.