THE STUDY OF FIBER-MATRIX INTERACTIONS VIA FT-IR MICROSCOPY AND NMR IMAGING

Model composites of Kevlar-49(R) and D-glass fiber/epoxy systems were analyzed using NMR imaging and FT-IR microscopy. The surfaces of both reinforcing agents were found to affect the curing process of the epoxy significantly. The NMR images reveal an accelerated;rate of cure in the proximity of the fibers as compared with the bulk, indicating strong interactions between the fibers and the matrices. To characterize these interactions spectroscopically, FT-IR microscopy was performed on Kevlar-reinforced microcomposites. Transmission spectra and IR functional group images reveal a preferential segregation of the epoxy resin to the fiber surface. Thin films of epoxy resin deposited on single Kevlar filaments were also examined using FT-IR microscopy. Spectra and IR images from these samples suggest that the amine group of the Kevlar fiber is reacting with the epoxide ring of the resin to catalyze the curing process.