Research On Strong Acid Ion Exchange Resin Loading Fe³⁺ Catalyzing The Systhesis Of Benzyl Acetate

As a kind of basic organic chemical material,ester acetate were widely used in different field.At present,ester acetate such as ethyl acetate,benzyl acetate,dioctyl phthalate were produced in traditional craft in our country,in traditional craft,corresponding acid(or anhydride)and alcohol are used as raw material,concentrated sulfuric is used as catalyst.When concentrated sulfuric is used in catalyzing reaction,catalyzing activity is higher,but there are more by-products,complex craft of purifying product,serious corrosion of equipment and morsewerage.In order to conquer the disadvantages in traditional craft,in latest years,more research and discussion about preparation of new catalyst, catalyzing mechanism and application have been done by in and abroad academician,and there are lots of harvest.For higher cost,these new catalysts are not used in commercial production replacing concentrated sulfuricl.So a kind of catalyst,which can be used in large scale production,replace concentrated sulfuric has higher catalyzing reactivity and selectivity,weak corrosion is easy to separate and used again is very important in technical development in esterifing field.In this text,strong acid ion exchange resin is choose as catalyst,the catalyzing reacticity is improved by loding metal ion to modify resin.The synthesis of benzyl acetate has been studied as a example conversion of acetate is index different factors,such as kinds of strong acid ion exchange resin,kinds of metal ion concentration of metal ion loading time loading temperature and drying temperature and so on,affecting the activity of catalyst have been studied.As experiment indicating,when Ni²⁺and Al³⁺are loaded,catalyzing acticity of resin in synthesis of benzyl acetate will decreases,when Fe³⁺is loaded,catalyzing acticity of resin in synthesis of benzyl acetate will increases, so Fe³⁺is used.The absorption of Fe³⁺on resin can be described by Langmuir adsorption isotherm,when the concentration of Fe³⁺is between 0.2222-1.006mmol/g(dring resin),the catalyzing capability of loading strong acid ion exchange resin will increase.The optimal condition in our experiment of loading Fe³⁺on resin initiative concentration of Fe³⁺is 32.55mmol/L,loading time is 3.0 minute,loading temperature is 35.0℃,drying temperature is 50.0℃,adsorption quantity 0.3671 mmol/g(drying resin).The kinetics of catalytic synthesis of benzyl acetate using strong-acid cationic-exchange resin loaded Fe³⁺was studied,After the influence of internal and external diffusion was eliminated,the quantity of catalyst is between 0.03333-0.1667g/g(acetic acid),the temperature is between 50.0℃-90.0℃,a equation of kinetics is described:-r_A = xⁿk₀e^-Ea/RT(C_AC_B-C_EC_W/K)=x^0.7992×2.081×10⁶×e^-55159.25/RT(C_AC_B-C_EC_W/4.31)And its accuracy was proofed. When loading resin is used as catalyst acetate and benmethylol are used as raw material technical condition of preparing benzyl acetate is studied.By orthogonal experiment,acid alcohol mol ratio,reaction temperature and quantity of catalyst are studied in synthesis of benmethylol.The optimal reaction condition is obtained:n_acetate:n_phenethylol=1:1,reaction time 150min,reaction temperature 100℃,conversion rate of acetate 69.30%.In the same reaction condition,compated to former catalyst,conversion rate of acetate increase 16.66%.Catalyst can be used again.After purifying,product is analysed by IR, the structure of product is the same to standard sample.Loading resin is analysed by IR adsorption of functional group in resin become strong.When loading Fe³⁺resin is used as catalyst,catalyzing capability is studied in synthesis of ethyl acetate and dioctyl phthalate,the result indicats loading of Fe³⁺on resin can increase catalyzing capability,but the mechanism of in catalyzing capability creasing needs further research...