C-13 LIQUID-STATE AND SOLID-STATE NUCLEAR-MAGNETIC-RESONANCE AND INFRARED STUDIES OF AMINE-CURED EPOXY-RESINS

The final network structure and the course of the reaction of bisphenol A diglycidyl ether with 1-cyanoguanidine dissolved in dimethylformamide in the presence of different accelerators have been studied by liquid-state C-13 nuclear magnetic resonance, solid-state C-13 cross-polarization/magic-angle spinning nuclear magnetic resonance and infra-red spectroscopies. Fractions of reactive groups such as oxirane rings, primary and secondary hydroxyl groups, imide and nitrile groups have been detected as functions of epoxy consumption and reaction conditions. Structural tautomerism of the hardener, the influence of water, the reaction of nitrile groups and other structural features of the curing system have been discussed.