Probing the role of surface treated montmorillonite on the properties of semi-aromatic polyamide/clay nanocomposites

Semi-aromatic polyamide/organoclay nanocomposites were generated through solution blending technique. Surface modification of the montmorillonite clay was performed with p-amino benzoic acid for ample compatibilization with the polyamide matrix. The polymer chains were produced from the condensation of 4-aminophenyl sulfone with sebacoyl chloride. Interaction between the two phases was established by modifying the polymer chains with amine end groups using 1% surplus diamine near the completion of the reaction. The effect of clay dispersion and the interaction between clay and polyamide chains on the properties of nanocomposites were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), tensile testing of thin films, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and water uptake measurements. The structural investigations confirmed the formation of delaminated nanostructures at low clay contents and disordered intercalated morphology at higher clay loadings. This morphology of the nanocomposites resulted in their enhanced mechanical and thermal properties. The tensile behavior and thermal stability significantly amplified while permeability decreased with increasing dispersibility of organoclay in the polyamide matrix.