Dispersion behavior of the layered-silicate in aerospace epoxy and its durability in aerospace

Polymer layered-silicate nanocomposites have unique and hierarchical structures which can provide for improvement of properties for polymeric materials. This, in turn, offers interesting potential for the improvement or modification of advanced polymeric matrix composites. Dispersion of the nanomaterials through processing for such composites is critical, as it determines the morphology and resulting properties of the nanocomposite. In this paper, dispersion behavior of organic layered silicates (OLS) through the processing procedure is presented. Behavior of the OLS in all stages of processing - in the solvent, the epoxy prepolymer, and in the epoxy through cure - will be discussed. Based on the understanding of the dispersion behavior of the OLS in the epoxy resin during processing, general process-morphology guidelines can be developed, and intercalated or exfoliated morphology of the layered-silicate epoxy nanocomposite can be regulated. Specific morphologies are desired for specific property improvements. Final morphologies are key, for example, to toughness or durability improvements. Durability of an intercalated morphology in low-earth orbit environments was examined, and results showed that the durability in the space environment was significantly improved after the addition of the layered silicate in the aerospace epoxy.