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dc.contributor.authorDong, YM
dc.contributor.author董炎明
dc.contributor.authorWu, YS
dc.contributor.author吴玉松
dc.contributor.authorWang, M
dc.contributor.author王勉
dc.date.accessioned2012-06-01T00:54:50Z
dc.date.available2012-06-01T00:54:50Z
dc.date.issued2001
dc.identifier.citationACTA POLYMERICA SINICA,2001,2:172-173zh_CN
dc.identifier.issn1000-3304
dc.identifier.urihttps://dspace.xmu.edu.cn/handle/2288/12584
dc.description.abstractA novel liquid crystalline polymer-hydroxyethyl chitosan(HECS) was synthesized in alkali system. The degree of molar etherification(DME) of HECS was controlled by both the amounts of ethylene oxide and the reaction time. DME of HECS specimens was from 0.2 to 5.4 measured by element analysis and NMR. All specimens formed typical cholesteric texture-fingerprint texture while dissolved in formic acid. HECS with DME >1.9 was water soluble, and the HECS aqueous solution also formed cholesteric phase with typical texture. The mesophase texture was detected both by polarized optical microscopy and scanning electron microscopy. Samples for SEM studies were treated by permanganic etching in order to increase the contrast. The studies were focused on the effect of DME on the critical concentration (c*) of mesophase formation for HECS/formic acid solutions. The results indicated that c* sharply increased with DME at first, and became independent as DME varied from 0.2 to 1.9. After that (DME>1.9), it regain obvious rise as DME continuously heightened. These results were explained by the variation of both persistence length q and molecular diameter d in Flory's semi-experience equation c* approximate to 8 q/x (x = 2q/d). The variation of DME of HECS related with two structural factors, i.e. the number and length of the substituent, the former affected c* slightly, but the latter affected c* evidently.zh_CN
dc.language.isozhzh_CN
dc.publisherSCIENCE PRESSzh_CN
dc.subjectcrystalzh_CN
dc.subjectdegree of molar etherificationzh_CN
dc.subjecthydroxyethyl chtiosanzh_CN
dc.subjectlyotropic liquidzh_CN
dc.subjectcholestericzh_CN
dc.subjectetchingzh_CN
dc.subjectscanning electron microscopyzh_CN
dc.titleStudies on chitin-based liquid crystalline polymers - V. Integrated influence of number and length of substituent on hydroxyethyl chitosanzh_CN
dc.typeArticlezh_CN


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