Studies On Synthesis Of Glucose-based Surfactants

Sugar-based surfactants were studied by lots of scientists recently.This kind of surfactants ont only had a good surface property, but also had better surfactant biodegradability, safety and environmental friendliness, than those from petrochemical products.Because glucose was solid at room temperature, it was hard to react with other materials. Besides, it would go carbonized easily under acidic,alkaline and high temperature conditions. So, the modification reaction of glucose was rarely studied before in the domestic.In this paper, glucose was modified to glucose polyoxyethylene ether first, to liquefy it, and then to cationic surfactants and non-ionic surfactants. Products synthesized were characterized, and the results showed the properties of product were as excepted.Firstly, glucose polyoxyethylene ether, with defined molecular weight, was prepared from glucose and ethylene oxide through oxide ring-opening reaction, using the Lewis acid as catalyst.The most important meaning of this reaction was that it changed the solid glucose into glucose ethoxylates, which was liquid at room temperature, so the follow-up modification would react easily. The innovative method of preparation of glucose polyoxyethylene ether was to add non-toxic hydrocarbon as solvent to improve dispersion. Following optimal conditions were obtained:the amount of catalyst was4%(wt) of raw material, the amount of solvent was1.1times the weight of glucose, the stirring speed was around500r/min, and the reaction temperature was kept80-90℃.Secondly, using fatty chloride and glucose polyoxyethylene ether prepared in the previous process, glucose fatty acid esters of polyoxyethylene were prepared, through Schotten-Baunmann method. We can get multi-ester which were deep esterfied under mild condition. Besides, this reaction used no catalyst and cost less time. The HLB value were obtained, though measurements and consideration.Finally, the glucose cationic surfactants was prepared. The specific methods of preparation were:glucose polyoxyethylene ether with2.5%boron trifluoride catalyst was heated to80℃, then epichlorohydrin was added slowly under stirring, and to keep this temperature for2hr after it was dropped up. Then it was cooled to60-65℃, with Na2CO3solution, to alkalize it. The tertiary amine was add by drop. The reaction temperature was kept constant until the solution was clear.The active substance content of product was measured, the result was47.5%. And this method of preparation of glucose cationic surfactants could be applied in industry.