Study On The Synthesis Of Itaconate Catalyzed By Lipase

The Itaconic acid(IA)is a chemically active dibasic organic acid.Its main derivative,Itaconate,is a very important chemical synthesis intermediate widely used in many research fields such as plasticizers,bio-based rubbers,degradable polymer material.At present,concentrated sulfuric acid is most used as a catalyst in Itaconate preparation,but concentrated sulfuric acid can causes severe corrosion to the equipment,and side reactions are easily generated during the preparation process,and a large amount of waste is generated.Lipase enzymatic esterification is a green and environmentally friendly catalytic method.The synthesis of esters from Itaconic acid,a bio-based chemical,is of great significance for the preparation of bio-based materials.Therefore,in this study,combined with the catalytic properties of enzymatic reactions,the synthesis of Itaconate esters using lipase as a catalyst was studied.1.In the process of enzymatic synthesis of di-n-butyl Itaconate,the lipase Novozyme 435 suitable for this esterification reaction was screened out,and the optimal conditions of the catalytic reaction process were optimized(enzyme amount,material ratio,water removal agent),solvent,etc.;compared the reaction effect of constant temperature shaking incubator(CTS)and STR,as follows:the amount of enzyme is 20%(wenzyme/wacid),reaction temperature At 65?,the acid alcohol molar ratio is 1:3,and the water scavenger is preferably CaC12.Under the optimal reaction conditions,the highest Itaconic acid conversion rate of the synthesis of di-n-butyl Itaconate in a solvent-free system with a stirred reactor was 58.6%,compared to a constant temperature shaking incubator system.The reaction time was shortened by 40%to 50%,and the yield of diester was increased by 17%.2.In the separation and purification process of di-n-butyl Itaconate,the components were analyzed and tested,and the excess reaction substrate free lipase was removed by rotary evaporation-filtration,and the Itaconic acid monobutyl ester mixed in the product were removed by alkali washing.The reaction target product was finally extracted by the extraction method,and the content of di-n-butyl Itaconate was 97.3%.3.In the study of the preparation of itaconic acid polyester by lipase as a catalyst,through the pre-experimental screening of enzyme species and glycol substrate,Novozyme 435 lipase was selected as the catalyst,and 1.4-butanediol was selected as the reaction substrate.T=75?,an acid-alcohol material molar ratio of 1:3,and an enzyme amount of 20%(w enzyme/w acid)are optimum process conditions.In the solvent-free system,the Itaconic acid polyester product can be obtained by a two-step reaction method using a self-built vacuum stirring reactor.The number average molecular weight(Mn)of the product is 947,and the weight average molecular weight(Mw)is 974,polydispersity(PDI)is 1.02.