1-(3-氨丙基)-2-甲基咪唑的催化合成、表征及应用

环氧树脂用的咪唑类固化剂多为固体和假性液体(低温下易析出的低熔点固体),工业应用不便。为了制得常温及低温下均呈液体的便于工业应用的咪唑固化剂,以1-氰乙基-2-甲基咪唑作为基本原料,骨架镍为催化剂,液氨为副反应抑制剂,乙醇作为溶剂,加压催化氢化合成液体咪唑固化剂1-(3-氨丙基)-2-甲基咪唑,考察氢气压力、液氨用量和催化剂循环使用次数对产率的影响,并通过元素分析、核磁共振氢谱和红外光谱对产物进行确证。结果表明,优化的反应条件为:反应温度100℃,氢气压力5 MPa,m(1-氰乙基-2-甲基咪唑)∶m骨架镍(湿重)]∶m(液氨)∶m(乙醇)=139∶27.8∶42.5∶278,此条件下,产率可达96%。产物低至-35℃也不凝固,能良好地固化环氧树脂,表现出优异的工业适用性和固化性。

Catalytic synthesis,characterization and application of 1-(3-aminopropyl)-2-methylimidazole

All imidazole type curing agent of epoxy resin are solid or pseudo liquid (tending to solid at low temperature),so its commercial application is difficult.In order to obtain true liquid imidazole compound,1-(3-aminopropyl)-2-methylimidazole was synthesized by high pressure catalytic hydrogenation and using 1-cyanoethyl-2-methylimidazole as the raw material,Raney-Ni as the catalyst,ammonia as the side reaction inhibitor and ethanol as the solvent.The effects of hydrogen pressure,ammonia amount and catalyst recycling times on the yield were investigated.The target compound structure was characterized by elemental analysis,1H-NMR and FT-IR.The results showed that the best yield of 96% was attained under the optimal reaction condition as follows: reaction temperature 100 ℃,hydrogen pressure 5 MPa,and m(1-cyanoethyl-2-methylimidazole)∶m(Raney-Ni)∶m(ammonia)∶m(ethanol)=139∶27.8∶42.5∶278.The product was not solidified at low temperature (low to -35 ℃) and it could cure epoxy resin successfully.It showed excellent industrial applicability and good curing ability.