Study On Synthesis Of Glyceryl Monostearate

In this thesis, glyceryl monostearate was prepared by using protected glycerol method, microwave radiation method and alcoholysis of methyl stearate method. Purpose is to research and development of high efficiency and low cost, a new method of synthesis of new craft GMS.Analysis was choosed to determine GMS in products. The chromatopraphy conditions were as follows: Agilent TC-C₁₈(2)(4.6×250mm, 5μm) column, and Agilent 1200 series RID refractive index detector, using acetonitrile: isopropanol: trifluoroacetic=80: 20: 0:05(volumn ratio) as mobile phase. Injection temperature at 35℃, detection at 35℃, flow rate of liquid at 1mL/min. With external standard method, the resolution up to 3.5, Adding 0.05% (by volume) of trifluoroacetic acid in the mobile phase, the monostearin tailing phenomena and isomerism resolution will improve significantly. In the concentration range of 0.5mg·mL^-120mg·mL^-1.The glycerin monostearate(GMS) was synthesized with protected glycerol and fatty by KF/ZnO solid base.The technology condition was obtained by orthogonal experiments as follows: molar ratio of 6:1,temperature of 230℃, time of 1.2 hour and the quantity of catalyst 2.5%w(stearic acid),The solid base KF/ZnO was prepared by impregnation method and loading amount of KF was 15%. It was a ctivated at 600℃,reacation time was 3 hour, the contant of glycerin monostearate is 66%, under the maximum technology condition.The glycerin monostearate was synthesized in this paper by microwave radiation method,the effects of molar ratio(glyceroborate to stearic acid ), Microwave power, time and quantity of catalyst on the content of GMS were investigated by orthogonal experiments. The technology condition was obtained by orthogonal experiments as follows: molar ratio of 3:1, microwave power of 400W, time of 25 min and the quantity of catalyst 0.2g. The solid base KNO₃/ZrO₂ was prepared by impregnate-on method and loading amount of KNO₃ was 20%. It was activated at 700℃, reacation time was 4 hour ,the contant of glycerin monostearate is 38.9%, under the maximum technology condition, the reaction rate is 6 to 10 times compare with conventional heating.The process of preparing monoglycerides by alcoholysis of methyl stearate was investigated. After the distillation of methanol, the methyl ester of stearic acid have been converted into 1-monoglycerides approaching to 48.8% when the ratio of methyl stearate to glycerol being 1:2.5, the amount of the catalyst of NaOH being 0.75%(methyl stearate w%),temperature of 220℃and th time of 15 min.The structure of glycerin monostearate was characterized with analyzing infrared spectrum and mass spectrum.