Preparation and Characterization of Organoclay-Filled, Vinyl Ester-Modified Unsaturated Polyester Nanocomposites

摘要

Organophilic montmorillonite clay - unsaturated polyester (UP) and vinyl ester oligomer (VEO) - unsaturated polyester nanocomposites were prepared and the formation of nanocomposites was evaluated by X-ray diffraction (XRD), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The VEO was prepared by reacting commercially available epoxy resin LY556 and acrylic acid and was used as a toughening agent for unsaturated polyester resin. Organoclay-filled hybrid VEO-UP matrices, developed in the form of castings, were characterized for their thermal and mechanical properties. Dynamic mechanical measurements indicated the presence of higher crosslink density for the clay-filled systems than unfilled systems. X-ray diffraction analysis infers the intercalation of the polymer molecules between the clay layers which in turn restricts the mobility of polymer in the vicinity of clay layers. A shift in T_g towards lower temperature was observed for nanocomposites. Significant improvement in the mechanical properties was also observed in the case of nanocomposites when compared with neat resin matrix.