Fiber Reinforced Epoxy Resin Composite Materials Using Carboxylate-Alumoxanes as Cross-Linking Agents

Abstract

ABSTRACTChemically functionalized alumina nanoparticles (carboxylate-alumoxanes) are used as the inorganic component of a new class of inorganic-organic hybrid materials. Lysine- or para- hydroxybenzoic acid-derivatized alumoxanes are readily prepared from the reaction of boehmite, [Al(O)(OH)]n, with the appropriate carboxylic acid. The peripheral organic hydroxides and amines of these carboxylate-alumoxanes either react directly with epoxide resins, such as the diglycidyl ether of bisphenol-A (DER 332), to form a hybrid material, or in the presence of an organic resin and hardener system to form a composite material. SEM and AFM show a uniform distribution of alumina nanoparticles within the resin matrix. The properties and cure times of the alumoxane hybrid and composite materials are distinct from both the pure resins and from a physical blend of the resins with traditional ceramic fillers. A significant increase in thermal stability and tensile strength is observed for both the hybrid and composite resin systems. In addition, both carbon fiber and carbon/Kevlar® matting have been successfully incorporated into the hybrid resin systems resulting in further property improvements.