Study On The Synthesis And Process Of Pentaerythritol Tris[3-(2-methyl Aziridinyl)Propionate]

Pentaerythritol tris[3-(2-methyl aziridinyl)propionate](PTMAP)is an aziridinyl compound and is currently mainly used as a room temperature crosslinking agent in waterborne coatings.Using isopropanolamine as the starting material,the isopropanolamine hydrosulfate was produced by the esterification reaction with sulfuric acid.Then the aqueous solution of methyl-azridine was obtained through the cyclo-chemical reaction.Finally,methyl-azridine and pentaerythritol triacrylate(PETA)underwent an addition reaction to generate the target product PTMAP.The purity of methy-aziridine is a key factor affecting the quality of the final product.In order to obtain high purity methyl-aziridine,this paper creatively improved the Wenker method for synthesis of aziridine and proposed a stepwise method.The high purity intermediate isopropanolamine hydrosulfate was separated after the end of the reaction between isopropanolamine and sulfuric acid.In this paper,the crystallization method and phase transfer catalysis method to synthesize isopropanolamine hydrosulfate were respectively investigated.Based on the research of the reaction mechanism,two different technical schemes have been studied and optimized by lab-scale tests and pilot-scale experiment.According to the process conditions,the obtained isopropanolamine hydrosulfate was analyzed by thin-layer chromatography and melting point apparatus,which showed that its purity was good.On this basis,in order to improve the operability of the subsequent reactions and ensure the quality of the product PTMAP,a series of studies have been carried out on the concentration of methyl-aziridine aqueous solution.This article investigated the factors that affect the product concentrate during the synthesis of methyl-aziridine and the effect of methyl-aziridine concentration on the synthesis process of PTMAP.The optimal process parameters of the synthesis process have been established,and which providing data support for industralization.In the end,the purity of the methyl-aziridine synthesized by the stepwise method is above 95%(GC),and its concentration is controlled between 60-80wt%.The quality of the product PTMAP reaches the international leading level.and the content of aziridine is greater than 80%.The intermediates and products were characterized by MS and 1HNMR.