Epoxy‐montmorillonite clay nanocomposites: Synthesis and characterization

Abstract

Nanocomposites of epoxy resin with montmorillonite clay were synthesized by swelling of different proportions of the clay in a diglycidyl ether of bisphenol-A followed by in situ polymerization with aromatic diamine as a curing agent. The montmorillonite was modified with octadecylamine and made organophilic. The organoclay was found to be intercalated easily by incorporation of the epoxy precursor and the clay galleries were simultaneously expanded. However, Na-montmorillonite clay could not be intercalated during the mixing or through the curing process. Curing temperature was found to provide a balance between the reaction rate of the epoxy precursor and the diffusion rate of the curing agent into the clay galleries. The cure kinetics were studied by differential scanning calorimetry. The exfoliation behavior of the organoclay system was investigated by X-ray diffraction. Thermogravimetric analysis was used to determine the thermal stability, which was correlated with the ionic exchange between the organic species and the silicate layers. The morphology of the nanocomposites was evaluated by scanning electron microscopy.

Clay-Containing Polysulfone Nanocomposites

“…Then, these two combined effects delay volatilization (Lu et al, 2006 An improvement of the mechanical properties could also be observed by the nanocomposite formation, as can be seen in Table 1. Although montmorillonite addition is known to reduce elongation at break (Nigam et al 2004), this feature was improved in the nanocomposite membranes probably due to a rearrangement of the clay mineral layers in the direction of deformation (Yeh et al, 2004). Lastly, hydrophilicity was increased with the increase of the clay content and the free energy of hydration values of the nanocomposite membranes were closer to the value of true hydrophilic materials, ΔG SW ≤ −113 mJ m −2 (van Oss, 1994).…”

Preparation, characterization and performance of poly( m -phenylene isophthalamide)/organically modified montmorillonite nanocomposite membranes in removal of perfluorooctane sulfonate

“…The performance of membranes strongly depends on the surface, sub-layer morphology, and top layer thickness and compactness (Van der Bruggen et al, 1999;Lu et al, 2006;Nigam et al, 2004). The influence of the concentration of OMMT as the additive on the membrane morphology was investigated using SEM apparatus.…”

Synthesis and Characterization of Soy-based Nanocomposites

“…This exchange of ions increased the spacing between the silicate layers, which in turn promoted the penetration of polymer chains into the space between layers. Nigam et al [16] reported that octadecylammonium ions exchanged for Na þ ions of pristine montmorillonite resulted in exfoliation of clay. They also reduced the Van der Waals interactions between the silicate layers, which favored penetration of the polymer between these clay layers.…”