Multi‐Nuclear NMR spectroscopic and proton NMR imaging studies on the effect of water on the silane coupling agent/matrix resin interface in glass fiber‐reinforced composites

Multi‐nuclear NMR spectroscopy and proton NMR imaging are used to investigate the absorption of water as well as the effect of water on the relaxation of the silane coupling agent/epoxy resin interface. For samples in which leaching occurred, proton NMR imaging is used to complement weight measurements by showing the amount and location of the water in the sample. 13C and 29Si solidstate NMR spectroscopy show that the water can interact with the silane coupling agent and affect the relaxation of the sample. Water can leach out the low molecular weight oligomers and/or further hydrolyze the silane coupling agent.