Alkyl Glucoside Synthesis And Physico-chemical Properties

Alkyl polyglycosides (APG), biosurfactant which have more advantages than traditional surfactants, possess some special performances, such as, no toxicity, no irritancy and prompt biodegradation, etc.. Therefore, they have been more and more popular in many fields.Alkyl polyglucosides were prepared by acid-catalyzed glycosidation of glucose monohydrate or glucose syrups with Cg-Cn fatty alcohol. The reaction gave an Alkyl polyglucosides with residual glucose <0.5%, polyglucoside content <2% and residual fatty alcohol <1%. The effects of reaction conditions on conversion (%) of glucose, color of products, average degree of polymerization (DP), ratio of a -D-glucopyranoside and B-D- glucopyranoside ( a / B ) were discussed. The formation of a -D-glucopyranoside is under thermodynamic control and B-D-glucopyranoside is formed under kinetic control. APG with DP 1.08~1.53 were obtained through control of molar ratio of alcohol and glucose from 9:1 to 3:1.Some analytical techniques, such as TLC, GC, ESI-MS, HPLC-MS, FT/IR, 1H NMR and 13C NMR, were applied for the analysis of APG DP-value and the ratio of a -D-glucopyranoside and B-D- glucopyranoside were calculated by 1H NMR data. Due to the addition of F3CCOOD as shift regent to the solvent D2O, disturb of hydroxyl can be removed. The ratio of glucopyranoside and glucofuranoside can be determined by 13C NMR date.Some physicochemical properties of APG, such as interfacial properties, foaming power, emulsifying power, stability in hard water were investigated as function of the alkyl chain and DP. The relation of structures of APG to properties thereof was discussed. The synergism of APG with other surfactants was also studied and the results showed C10-APG and C12/14-APG showed excellent performances and synergism.