Functionalization and incorporation of montmorillonite clay in epoxy matrix for aerospace hydrophobic coating application
clay, epoxy, nanocomposite, hydrophobicity.
Thermosetting polymer matrix nanocomposites and nanostructured inorganic fillers have been presenting higher industrial demand in recent years. Recent research in this area seeks to incorporate charge at low mass percentages (less than 5%) to maximize nanocomposite properties without affecting factors such as toughness. In this work, polymer-clay nanocomposites were produced from epoxy resin and a montmorillonite clay. A 3% wt. Clay content was incorporated into the resin by acetone dispersion, mechanical stirring and vacuum application. The nanocomposites obtained were deposited as films on stainless steel plates. Commercial clay was treated using ethylene glycol to remove interlamellar compounds. The material was functionalized with three different coupling agents, called silanes, (3-Aminopropyl) triethoxysilane (APTES), Triethoxyvinylsilane (TEVS) and 3- (Trimethoxysilyl) propyl methacrylate (MEMO). The modified minerals were evaluated by X-ray Diffraction, Fourier Transform Infrared Spectroscopy and Specific Surface Area Analysis by the BET method. The analyzes indicated that the obtained materials presented exfoliated structure before incorporation in the resin, with the silane agents incorporated in the interlamellar space of the argilomineral, which was observed through the significant increase in the basal spacing of its structure and reduction of surface area. Atomic Force Microscopy and Contact Angle analyzes performed on the obtained nanocomposites indicated that the presence of coupling agents superficially modified the nanocomposites, varying their roughness and obtaining an approximately 45% increase in contact angle for the nanocomposite containing TEVS. For the nanocomposite containing APTES, analyzes indicated a tendency to increase hydrophilicity.