Sasai Yasushi, Yamauchi Yukinori, Kondo Shin-ichi, Kuzuya Masayuki
Laboratory of Pharmaceutical Physical Chemistry, Gifu Pharmaceutical University, Gifu, Japan.
Chem Pharm Bull (Tokyo). 2004 Mar;52(3):339-44. doi: 10.1248/cpb.52.339.
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.
基于电子自旋共振（ESR），研究了羧甲基纤维素、几丁质和壳聚糖等几种取代纤维素的机械诱导自由基（机械自由基）的形成，并与等离子体诱导自由基进行了比较。室温ESR光谱具有多组分光谱，且彼此的图谱不同。在振动研磨过程中，每种取代多糖中的机械自由基浓度在达到最大值后逐渐降低，同时分子量也随之降低。最有趣的事实之一是，尽管已知机械自由基是由多糖的1,4-糖苷键断裂形成的，但与等离子体辐照的情况一样，组分自由基都是基于葡萄糖的自由基。
