Study On Synthesis Of Sunflower Oil Sugar Ester Catalyzed By Inverse Phase-transfer Catalyst

In recent years, the industrial of the surfactant has developedrapidly. But the production and application cause a lot of environmentpollution, its development gradually tends to green environmentprotection and biodegradable. As a new type of excellent nonionicsurfactant, biodegradable sucrose fatty acid ester-based surfactants, canbe synthesized by ester exchange reaction of sucrose and fatty acidmethyl ester. Its broad source of raw materials are derived from naturalrenewable resources, in line with the trend of development of thesurfactant, and should be vigorously developed.Sugar fatty acid ester-based surfactant has good surface activity.With high emulsifying capacity, solubilization, dispersion, wettabilityand bubble, it has a wide range of applications, such as food additives,emulsifier of cosmetics, dispersing agent in the pharmaceutical drugs,pesticides in agriculture and so on. In this paper, fatty acid methyl esterwas prepared by ester-exchange method, using the sunflower oil andmethanol as reactants, KOH as catalyst. Then the effects of differentfactors on the synthesis of sunflower oil sugar ester are investigated indifferent method.Micro-emulsion method was studied that sunflower oil sucroseester was synthesized by using water as solvent, fatty acid methyl esterand sucrose as reactants, fatty acids potassic soap as emulsifier, catalystgained by comparing catalytic effect of the different catalyst under thesame conditions. The effects of different factors on thetransesterification reaction are investigated. The better conditions forsynthesizing were established. It was shown that, amount of fatty acidsmethyl ester: amount of sucrose=2.5:1, reaction temperature85℃,catalyst dosage of4wt%reactants, reaction time7h, emulsifier dosageof10%reactants, the conversion rate may reach to65.32%. Solvent method was also studied. Using DMSO as solvent,sunflower oil glucose ester was synthesized by glucose and fatty acidmethyl ester, catalyzed by DMAP and K₂CO₃compound. The betterconditions for synthesizing were established. It was shown that, amountof fatty acids methyl ester: amount of glucose=1:1, reaction temperature85℃, catalyst dosage of6wt%reactants, reaction time11-12h, theconversion rate may reach to71.3%.The analysis results of the experiment show that the inversephase-transfer catalyst DMAP has good catalytic properties, mildreaction conditions, higher conversion rate, which achieved expectedresults. In addition, the conversion rate of the method using DMSO assolvent is higher than that of the micro-emulsion method. However,DMSO is poisonous and residual solvent may exist in products purified,which limits the application in the field of food. So synthesis ofsunflower oil sugar ester, using water solvent method, is more secure.Sugar esters synthesized in different solvent were purified indifferent method. Furthermore, FT–IR and NMR were used in thecharacterize of the products. The physicochemical properties andantioxidant stability of the two non-ionic surfactants were alsodetermined and compared.