Aerospace Composite Materials Delivery Order 0003: Nanocomposite Polymeric Resin Enhancements for Improved Composite Performance

摘要

Epoxy nanocomposites were successfully prepared using different montmorillonite-based organoclays with an epoxy resin system including several added to fiber preforms. The cation exchange capacity of the clays was the most important factor affecting the clay exfoliation. The addition of clays does not significantly alter the viscosity or cure kinetics so that the modified resin will still be suitable for liquid composite molding techniques such as resin transfer molding. The cure and morphology were examined using differential scanning calorimetry and in situ small-angle x-ray scattering (SAXS). The morphology was also examined by wide- angle x-ray diffraction, SAXS, and transmission electron microscopy. The exfoliation process requires excess energy available only when the resin exothermic reaction takes place or the temperature is very high. The moduli of the polymer-silicate nanocomposites increased over the unmodified resin. The oxygen plasma erosion rates, solvent absorption in methanol and acetone, and the solvent diffusion coefficients of the nanocomposites were all reduced for the nanocomposites. The thermal oxidative properties of the nanocomposites, however, were not enhanced. Additional work is underway examining covalently bonded organic modifiers to the inorganic clays.