Preparation And Physiochemical Properties Of Alkyl Glycoside Tartrate

In this paper,a novel anionic surfactant,alkyl glucoside tartrate（APG-ET）,was synthesized from maleic anhydride and laurylglucoside by two-step method.Aiming at the disadvantage of poor water solubility of alkyl polyglycosides at room temperature,derivative alkyl polyglycoside tartrate was greatly improved,and its surface tension was also significantly reduced.The data display that the surface tension of the alkyl glycoside tartarate surfactants was significantly reduced（23.65mN/m）compared with alkyl glycosides,which indicating that alkyl glycoside tartarate has strong activity at the air/water interface.And the critical micelle concentration（CMC）of APG-ET is 1.54×10^-4mol/L.The main contents of this thesis are as follows:（1）Synthesis and identification of alkyl glucoside tartrate.Alkyl glucoside tartrate was synthesized in two steps:In the first step,the hydroxyl group was provided by Laurylglucoside,which was esterified by the reaction of alkyl glycoside and maleic anhydride,and the second,double-bond epoxy ring on maleic anhydride was opened to obtain vicinal diol structure.The product structure and yield is determined by High performance liquid chromatography（HPLC）,GB/T 1677-2008（determination of epoxy value）,Fourier transform infrared spectroscopy（IR）,and other methods.The optimal reaction conditions were determined by orthogonal experiment,and the orthogonal experiment data were analyzed by Minitab software.The result display that the esterification reaction can be carried out smoothly and the average conversion rate of alkyl glycosides reached 87.1%in the first step;In the second step,the average conversion rate of the double bond obtained by iodimetry can reach 98.3%and the average yield of epoxy open-loop was 81.3%according to the standard GB/T 1677-2008.（2）Surface properties and adsorption behavior of alkyl glycoside tartarate.Wilhelmy plate method was used to determine critical micelle concentration（CMC）and the equilibrium surface tension(γ_eq).The dynamic surface tensions in the range0.01¹00s were measured by maximum bubble pressure method.The well-known Ward–Tordai equation was employed to analyze the adsorption behavior of the alkyl glycoside tartarate surfactants.The parameters and effective diffusion coefficients(D_eff)of dynamic surface tension have been calculated and analyzed.The equilibrium surface tension results showed that the surface tension of the alkyl glycoside tartarate surfactants was significantly reduced compared with alkyl glycosides,which indicating that APG-ET has strong activity at the air/water interface.The CMC value of APG-ET was significantly increased due to the increase of hydrophilic group.In addition,the area of the surfactant molecules occupied by the surfactant molecules at the interface(A_min)also increased significantly.According to the values of dynamic surface tension parameters,the APG-ET reaches the meso-equilibrium region faster,is easier to absorb to the interface,and has lower adsorption energy compared with APG.According to Ward–Tordai equation,the D_effff values were calculated,result that the distribution of D_eff decreased gradually with the increase of phase concentration.The adsorption behavior is not always controlled by diffusion throughout the process.