Process Development for Alkyl 2-Cyanoacrylate

• Main Author: 鄭聰堯
• Other Authors: 張仁瑞
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/88554067362702831998

碩士 === 國立中正大學 === 化學工程研究所 === 88 === Production of ethyl 2-cyanoacrylate (ECA) involves ‘polymerization’ and ‘pyrolysis’ steps. The goal of this research was to improve the process performance by the development of solid acid catalysts for pyrolysis and by a solvent system for polymerization. Normally, solution polymerization with organic solvent was used. The most usage solvents are benzene, toluene and carbon tetrachloride. However, because of emission of the solvents causes the potential hazard in operator and environment, replacement of the solvent system is necessary. Besides, during the polymerization process, water removal rate, which greatly affects the molecular weight of the polymer, is influenced by the properties of water-solvent azeotropic mixture. By the systematic study, solvent system of cyclohexane and toluene mixture was proven of perfect performance not only for the degree of polymerization but also for the reaction rate. Additionally, phase separation, which will be benefit for the separation of polymer from solvent, has also been observed. For the pyrolysis step, byproducts such as triethyl phosphate (TEP) and diethyl α, α’-dicyanoglutarate (DEDCG) greatly affect product properties. TEP is formed concomitantly with the production of the ECA and DEDCG is a product of the Michael addition between ethyl 2-cyanoacetate and ECA. For the pyrolysis step, which oligomer is cracked to ECA, using solid-acid catalyst reduced the impurity in final product. The reasons for the improvement are caused by lowering reaction rate for impurity formation resulting from the decrease of cracking temperature.