材料期刊网

以D-葡萄糖为原料，经全乙酰化、在SnCl 4催化下与脂肪醇糖苷化、脱保护3步反应合成了7种不同碳链长度的烷基-α-D-吡喃葡萄糖苷。利用核磁共振、表面张力仪和偏光显微镜等对其进行结构、表面张力和热致液晶等性能测试，结果表明，当烷基-α-D-吡喃葡萄糖苷烷基链长（ n）为6～9时，均有发泡和乳化性能，其中正壬基-α-D-吡喃葡萄糖苷具有最佳的发泡和乳化性能；烷基糖苷（n＝6～9）的表面张力（γCMC）及临界胶束浓度（CMC）均比较低；饱和吸附量（Γmax）随烷基链的增长而减小，饱和吸附面积（Amin）随烷基链增长而增大；形成胶束时的标准自由能（ΔGmic ）和吸附自由能（ΔGads ）均为负值，其绝对值随烷基链增长而越来越大，其中正辛基-α-D-吡喃葡萄糖苷的表面活性最好；烷基糖苷（n＝4～9）对皮肤均无急性刺激作用；所合成的烷基糖苷均具有热致液晶行为，随烷基链长的增加，液晶相的温度范围变宽，液晶相的稳定性越好。

Alkyl α-D-glucopyranosides were synthesized with D-glucose as the raw material by three reactions involving acetylation , SnCl 4 catalyzing glycosylation with the aliphatic alcohols and deacetylation . The structures of alkyl α-D-glucopyranosides , their surface properties and thermotropic liquid crystalline properties were determined through NMR , surface tensiometer , polarization microscope and so on .The results show that alkyl α-D-glucopyranosides possess foaming and emulsifying power as their hydrophobic alkyl chain length n=6~9 , wherein n-nonyl α-D-glucopyranoside has rather superior foaming and emulsifying power .The values of the surface tension (γCMC ) and the critical micelle concentration ( CMC) of the alkyl glycosides ( n=6~9) are very low, their saturated adsorption capacity (Γmax ) decreases with increasing alkyl chain length , and their saturation adsorption area ( Amin ) increases with the increase of alkyl chain lengths .The standard free energy of micellization(ΔGmic ) and standard free energy of adsorption (ΔGads ) for alkyl glycosides ( n=6~9) are all less than zero, and the values of ΔGmic andΔGads are more negative with the increase of the alkyl chain length . The n-octyl α-D-glucopyranoside has the best surface activity .Furthermore, the alkyl glucosides(n=4~9) does not have any skin irritation .Finally, all of alkyl α-D-glucopyranosides exhibit thermotropic liquid crystalline behavior , the temperature range of the thermotropic liquid crystalline phase becomes broader , and the stability of the thermotropic liquid crystalline phase becomes stronger with the increase of alkyl chain length.