Effective preparation of clay/waterborne Azo-containing polyurethane nanocomposite dispersions incorporated anionic groups in the chain termini

Abstract

In this study, the effect of organically modified montmorillonite (OMMT) on the properties of water-based polyurethane (WPU) colored coatings was studied. For this, a dye incorporated waterborne polyurethane anionomer (WPUA) containing 3 mol% of 2,2-Bis(hydroxymethyl) propionic acid (DMPA) as a matrix polymer was synthesized. Cloisite30B/WPUA nanocomposites containing various amounts of OMMT were prepared by the insitu method. The structural, morphological, and thermal characteristics of Cloisite30B/WPUA nanocomposites were performed by WAXS, transmission electron microscopy (TEM), scanning electron microscopy (SEM), FT-IR spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). From the WAXS and TEM analyses, it was found that the OMMT layers were completely exfoliated and dispersed in the PUA matrix. The influence of different OMMT loading on the properties of the nanocomposite was also investigated. OMMT/WPUA nanocomposites exhibited enhanced thermal and scratch resistance relative to the pure WPUA. The DSC results indicated an increase in Tg and melting temperature of the OMMT/WPUA nanocomposites compared to pure WPUA.