Study On The Synthesis And Properties Of Alkyl Polyglucosides

Alkyl polyglucosides(APG) is a new kind of non-ionic surfactant which is prepared by starch or glucose and fatty alcohol.APG has low surface tension,high activity,excellent foaming and stability properties,better decontamination ability,best match with other active surfactant, innocuity,no thrill,sterilize,fine bio-degradation,strong ability of decontamination ect.In this thesis,octyl polyglucosides(OPG) is synthesized by the reaction of lauryl alcohol with glucose in the presence of catalyst.By contrast to synthetic process,we had selected the two steps way to prepared APG.Although,there are some research and applications of APG in some country and area,we had innovation on the base of them.Though selected catalyze,we had selected plant acid and opposite toluene sulphur acid as a catalyze system.Though our probed into synthetic techniques of APG.We had attained the optimized reaction temperature,optimized reaction dosage and optimized reaction time.The process avoids using too much long carbon alcohol and then the product doesn't contain much APG byproducts which is brought by high temperature and so has more applications.Meanwhile,the excess alcohol can be reused after treatment which can cut down the total cost.Emphases of this thesis are the selection of acidic catalyst and the optimization of reaction condition such as catalyst/glucose molar ratio,alcohol/glucose molar ratio,reaction temperature, and reaction time.First,we study the catalytic efficiency of inorganic acid,organic acid and a bicatalyze system.And find out that LASH/PrD is the best catalyst in the glycosidation.Then the optimal reaction conditions are confirmed through orthogonal test:Catalyst/glucose molar ratio:0.02/1,Alcohol/glucose molar ratio:6/1,Reaction temperature:120^C,Reaction time:2.2h. The author applied orthogonai experiment to study the influence of selected factors on glycoside yield.The synthesis technology of C₈APG,C₁₀APG,C₁₂APG were optimized by L₉(3⁴).The results of variance analysis show that alcohol/glucose molar ratio is the most important factor.The components and structure of C₈APG were characterized by HPLC and IR,and the results showed that the APG was synthesized successfully.The structure of APG is analyzed by means of infrared absorption spectroscopy,recording the characteristic absorption skeleton vibration peaks C-O-C(1500cm^-1-1650cm^-1),and the stretching vibration peaks C-O and C-O-C(1100cm^-1-1000cm^-1).The spectrum proves the structure of APG.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.The relation of structures of APG to properties thereof was discussed.And the results showed:At 21℃, the surface tension of product water solution(1.0g/L) is only 25mN/m,lower than most of other surfactants.APG's foam stability is better than that of MOA-9.A logarithmic chart can be drawn based on the different consistence surface tensions.The CMC of product can be read from the break point of the curve.