Inorganic−Organic Hybrid and Composite Resin Materials Using Carboxylate-Alumoxanes as Functionalized Cross-Linking Agents

Abstract

Chemically functionalized alumina nanoparticles (carboxylate-alumoxanes) are used as the inorganic component of a new class of inorganic−organic hybrid materials. Lysine- or p-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 with associated EDX analysis, and AFM shows a uniform distribution of alumina nanoparticles within the resin matrix. Solid-state 13C and 27Al NMR spectroscopy demonstrates that the carboxylate-alumoxane nanoparticles are chemically bound to the epoxide resin matrix. The model compounds PhOCH2CH(OH)CH2OPh (1), PhOCH2CH(OH)CH2NHnPr (2), and PhOCH2CH(OH)CH2NHiPr (3) have been prepared to assist in the ...