Synthesis Of A New Cosolvent Of Gasoline Blends, Sweetener Sucralose And 2-methoxyethyl-(meth) Acrylate

The thesis includes three parts:first is the design,preparation of a new cosolvent and its effect on the solubility of gasoline blends,second is the synthesis research of sweetener sucralose,third is the synthesis of 2-methoxyethyl(meth)acrylate.1.The design,preparation of a new cosolvent and its effect on the solubility of gasoline blendsAlong with worldwide energy lack and environmental pollution,methanol as the alternative fuel is becoming more and more concerned.Methanol has several advantages such as its rich resource and low emission.However,the major issue with methanol-gasoline blends as automotive fuel is the separation of the fuel,a heavier alcohol-rich phase and a lighter gasoline-rich phase,at low temperatures.Separation can cause serious operational problems and even damage in the engine.The separation of methanol from gasoline could be solved by adding additives into fuel blends,such as dimethoxymethane(DMM) and surfactant/cosurfactant pairs. But the low boiling point of DMM(42℃) would cause an increase in the Reid Vapor Pressure(RVP),and the high boiling point of surfactant/cosurfactant pairs would result in residues.In this article,we conveniently prepared ethoxymethoxymethane(EMM) in a batch reactive distillation mode using cation-exchange resin Amberlyst 35 as the catalyst for the first time.EMM,with a boiling point of about 62℃,was not only to be a fine industrial solvent similar with DMM and diethoxymethane(DEM),but also was found to be an excellent cosolvent for methanol-gasoline blends,especially at high methanol content up to 20%v/v even from -20 to 20℃with low concentration of EMM.The boiling point of EMM is in the major boiling point range of gasoline, which might decrease the RVP and reduce the risk compared with that of DMM as cosolvent in methanol-gasoline blends.The main innovations of this article:1) EMM was conventiently prepared by ethanol,methanol and formaldehyde using cation-exchange resin as the catalyst for the first time. 2) CaCl₂ was added to the distillation to separate DMM,DEM and EMM from water,alcohols and formaldhyde.3) The reaction was very efficiently carried out in batch reactive distillation mode with up to 92%conversion of formaldehyde.4) Lots of advantages including ease of separation,mild reaction conditions and elimination of wastes could be achieved when cation-exchange resins were used as the catalyst.2.The synthesis research of sweetener sucraloseSucralose is a new and high-sweet sweetener,which is purely-tasting, highly-safe and no caloric,and stability in physics-chemical properties.It has no side effect and is not absorbed in human body,it is a good sweetness agent to the patients with diabetes and adiposis instead of the sucrose.It has been widely used in drink,food,daily sweetener and so on.By analyzing the different synthetic routes,the mono-ester protection method of making sucralose is an effective way.But selecting chlorination of hydroxyl group in sucrose-6-acetate is the key process that influences the yield of sucralose-6-ester.The selecting chlorination of sucrose-6-acetate and deacetylation preparing sucralose is deeply studied in the thesis.Sucrose-6-acetate was selective chlorinated in N,N-dimethyllformamide(DMF) solvent by Vilsmeier reagent which was subjected thionyl chloride to DMF to obtain sucralose-6-acetate.Finally,sucralose is obtained from sucralose-6-acetate by the way of interesterification in methanol,sodium methoxide as catalyst.The orthogonal experiments were designed in the step of selective chlorination to optimize the reaction conditions.The optimized parameters had been obtained.This method had many advantages:high yields,easy operations.The main innovations of this article:1) Toluene was used in the step of chlorination to control the reaction temperature.2) The DMF solvent of sucrose-6-acetate was added into the Vilsmeier reagent, so all hydroxyl groups of sucrose-6-acetate could make complexes with Vilsmeier reagent in low temperature.3) Selective chlorination of 4,1',6'-OH separately in the different temperature stage.3.The synthesis of 2-methoxyethyl(meth)acrylateOne of the outstanding chemical developments of recent years in the industrial field is the rapid rise of synthetic resins to a position of considerable importance.The 2-methoxyethyl(meth)acrylate is an important monomer of the polymers of the acrylic acid derivatives.The synthesis of 2-methoxyethyl(meth)acrylate with(meth)acrylic acid and ethylene glycol monomethyl ether at the catalysis of p-toluenesulfonic acid were described in this paper.The reaction inclined to self condense that will cause the dropt the yield of 2-methoxyethyl(meth)acrylate.In order to prevent the condensation, hydroquinol was added in the reaction mixture to make the reaction carried out smoothly.Besides many other important factors that influence the productivity are optimum material proportion,suitable esterification time,the dosage of inhibitor,the control of coarse ester acidity.The product with high quality and productivity was obtained.Thanks to the low cost of the materials,this method could be applied in the industrial fields.