壳聚糖衍生物的红外光谱分析

合成了以下多种壳聚糖衍生物并测定了它们的红外光谱。这些衍生物是羧酸化壳聚糖 ,苯甲酰化壳聚糖 ,氰乙基壳聚糖 ,羟丙基壳聚糖 ,羟乙基壳聚糖 ,N -羧甲基化壳聚糖 ,壳聚糖的苯甲醛西佛碱 ,N -乙基壳聚糖 ,N -丁二酰化壳聚糖 ,N -顺丁烯二酰化壳聚糖 ,N -邻苯二甲酰化壳聚糖和N -乙酰化壳聚糖。观察到随壳聚糖脱乙酰度的增加 ,酰胺Ⅰ谱带移向低频 ,而酰胺Ⅲ谱带和醇羟基谱带移向高频 ,结果可用氢键的变化加以解释。脂肪族酰化壳聚糖的取代基长度对C =O位置影响很小 ,它们的C =O都能与邻近的N -H和O -H基生成相似的氢键。氰乙基壳聚糖的取代度影响了C -O谱带的位置 ,低取代的 1 0 70cm- 1 和 1 0 30cm- 1 双峰在高取代时被 1 0 61cm- 1 单峰所代替。通过IR测定 ,对丁二酰化壳聚糖和顺丁烯二酰化壳聚糖观察到含自由羧基端的线形取代 ,对邻苯二甲酰化壳聚糖 ,在反应程度较高时还出现环状取代。羧酰化壳聚糖、氰乙基壳聚糖和邻苯二甲酰化壳聚糖的取代度可分别用吸光度比A1 740 /A1 52 7,A2 2 4 9/A1 52 7和A1 71 2 /A1 391 测定

FTIR Spectroscopic Determinations of Chitosan Derivatives

Various chitosan derivatives were synthesized, and their FTIR spectra were determined . These derivatives are O-acylated chitosan, O-benzoyl chitosan, O-cyanoethyl chitosan, O-hydroxypropyl chitosan, O-hydroxyethyl chitosan, N-carboxymethyl chitosan,phenyl formaldehyde Schiff's base of chitosan, N-ethyl chitosan, N-succinyl chitosan, N-maleoyl chitosan, N-phthaloyl chitosan, and N-acetyl chitosan. It is observed that the amideⅠbands migrated to low frequency but the amide Ⅲ bands and hydroxyl bands moved to high frequency with the increase of degree of deacetylation for chitosan. The results can be explained by the variation of hydrogen bonding. The influence of length of substituent for acylated chitosan on the wavenumber of C=O stretching was very small, because their C=O formed similar hydrogen bonding with N-H or O-H groups. The degree of substitution (DS) for cyanoethyl chitosan affected the position of C-O bands. 1061cm -1 single band at high DS appeared instesd of 1070 and 1030 cm -1 double bands at low DS. After IR determination, a linear substituent with a free carboxyl group can be observed for butanedioic chitosan and maleoyl chitosan , nevertheless a circle-like substituent was found for phthaloyl chitosan at high degree of reaction. The DS of acylated chitosan, cyanoethyl chitosan and phthaloyl chitosan can be measured using the absorption ratio A 1740 / A 1527 , A 2249 / A 1527 and A 1712 / A 1391 respectively.