Epoxy resin curing reaction studied by proton multiple-quantum NMR

This study demonstrates that the curing reaction of thermosetting polymers, in particular, epoxy resins cured with aliphatic amines, can be characterized by different multiple-quantum (MQ) NMR experiments performed in low-field spectrometers. Measurements of the curing reaction at 40 degrees C, 70 degrees C, and 100 degrees C are carried out to obtain the kinetic parameters like induction time, vitrification time, polymerization rate, and activation energy being consistent with data obtained by other traditional and complementary techniques. Besides, it is demonstrated that H-1 MQ-NMR spectroscopy is a successful approach to overcome the experimental challenge arising from the characterization of high dipolar-coupled polymers to study the network structure and segmental dynamics of thermosetting polymer networks. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1324-1332