Study And Optimization Of Direct Synthesis Of 4-hydroxybutyl Acrylate By Esterification

Thermosetting acrylic resins are widely used as automotive finishes and varnish,due to their chemical resistance,weather resistance,lightness,fullness,mechanical properties and adhesion.Among them,the hydroxy acrylic resin coating can be cured at room temperature or low temperature,has good polishing and polishing properties,and is a main type of varnish for automotive repair industry.The type of hydroxyl monomer has a great influence on the performance of the resin,in order to develop and expand automotive coatings,new types of monomers are continuously researched and developed.4-hydroxybutyrate acrylate is a new type of hydroxyl monomer that has gradually developed in recent years.In this paper,4-hydroxybutyrate acrylate was synthesized by direct esterification using acrylic acid and 1,4-butanediol as raw materials.The types and amounts of catalyst,the type of polymerization inhibitor,reaction time,temperature,dropping temperature of acrylic acid,dropping time and water-carrying agent on the reaction were investigated.The crude 4-hydroxybutyrate acrylate was used as the raw material for extraction experiments.Cyclohexane can be used as an extraction agent for 1,4-butanediol diacrylate;Dichloromethane can be used as an extractant to extract 4-hydroxybutyrate acrylate from the aqueous phase,and the solvent ratio is an important factor affecting the extraction effect.When other conditions do not change,the effect of temperature on the extraction effect is small,and a good extraction effect can be achieved at a temperature of 20℃.Therefore,the optimum extraction temperature is 20℃.Based on the experimental basis,the production process of high-purity4-hydroxybutyrate acrylate was designed.Based on the experiences and methods provided by Aspen Plus,this article used NRTL’s physical equations to simulate the entire process,and based on this model,physical properties of 4-hydroxybutyrateacrylate and 1,4-butanediol diacrylate not found in Aspen Plus were evaluated to obtain missing properties.The optimum temperature for the extraction process operation,the optimum extractant flow rate,the optimum feeding position of the rectification operation,the number of trays,the optimum reflux ratio,and other process parameters were found.The simulation results are consistent with the experimental results.The purity of the 4-hydroxybutyl acrylate product produced in this process can reach 99.4%,and the purity of 4-hydroxybutyl acrylate can meet the target requirements.The entire process is extracted first and then rectified.At the same time,the process simulation has a certain guiding effect on the production of high-purity 4-hydroxybutyrate acrylate.