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 bispheno l A diglycidyl ether with 1-cyanoguanidine dissolved in dimethylformam ide in the presence of different accelerators have been studied by liq uid-state C-13 nuclear magnetic resonance, solid-state C-13 cross-pola rization/magic-angle spinning nuclear magnetic resonance and infra-red spectroscopies. Fractions of reactive groups such as oxirane rings, p rimary and secondary hydroxyl groups, imide and nitrile groups have be en detected as functions of epoxy consumption and reaction conditions. Structural tautomerism of the hardener, the influence of water, the r eaction of nitrile groups and other structural features of the curing system have been discussed.