Cyanoethylated Isophoronediamine—New Potential Hardener for Epoxy Resins

Cyanoethylation of isophoronediamine catalyzed by acidic catalysts was investigated. A number of both homogeneous and heterogeneous catalysts have been examined. Cyanoethylation of isophoronediamine was carried out at temperature of 60-70 degrees C with the addition of a small amount of water as a promoter. The best results were obtained for the homogeneous catalysts. Among the examined catalysts, methanesulfonic acid showed the highest activity, significantly better than acetic acid. Heterogeneous catalysts like sulfate functionalized silica and acidic ionic liquids were less active. For an acrylonitrile/NH2 molar ratio of 2.2:1, at a temperature of 70 degrees C for 48 h, the conversion of isophoronediamine was close to 100%. The reaction product contained in total more than 95 wt % of the tri- and tetracyanoethylated isophoronediamines.