Study On The New Technology Of Syntheszing The Glycerin Monostearate

The glycerin monostearate is a kind of .important polyol non-ionic surfactant. It used to be asemulsifier applied for food, and antistatic agent for polyolefine. The thesis introduces the primary physicaland chemical properties of glycerin monostearate and common synthetic methods of monoglyceride, andreviews the actuality for apply about glycerin monostearate, at a same time prospects the trends ofdevelopment of monoglyceride at home and abroad. The synthetic technique of glycerin monostearate isintroduced in this paper emphatically.The group protection method is adopted to synthesize glycerin monostearate. When the reactiontemperature and reaction time are fixing, the cyclohexane is used as solvent to carry out water, the optimumtechnology condition was obtained by optimized experiment as follows: glycerin/acetone/cyclohexane/stearic acid/catalyst=1/1.2/3.8/2.5/0.04. The yield of glycerin monostearate is 80.0% and the contant ofglycerin monostearate is 86.0% under the optimum technology condition, but when the chloroform is usedas solvent, the yield of glycerin monostearate is 75.9%, and the the contant of glycerin monostearate is83.0%.The glycerin monostearate was synthesized in this paper by epichlorokydrin method withepichlorokydrin and stearic acid as reactants and potassium hydroxide as a catalyst. The effects of ringopening temperature, the ring opening time, the hydrolytic reaction time and hydrolytic reactiontemperature on yield and purity of GMS were investigated with orthogonal experiment. The result showsthat the ring opening temperature is mostly factor to influence on the yield of GMS. In this foundation, theoptimum reaction condition was obtained by condition experiment as follows: the ratio of stearic acid toepichlorokydrin is 1:2.5-3.5, the dosage of KOH is 0.8～1.2%(w), ring opening reaction temperature is 140℃, reaction time is 6h, hydrolysis temperature is 100℃, hydrolysis time is 2h. The ethanol was used assolvent to refine the product according to the difference of solubility. The yield and content of GMS is65.4% and 76.7% respectively accoding to the process.The content of glycerin monostearate was determined with oxidation process of periodic acid, thestructure of glycerin monostearate was characterized with determining melting point, analyzing infraredspectrum and mass spectrum.