The influence of Ni/Mg content of synthetic Mg/Ni talc on mechanical and thermal properties of waterborne polyurethane nanocomposites

Abstract

Waterborne polyurethanes (WPUs) present interesting properties when compared to their solvent-based counterpart besides being organic solvent free. WPUs also present some drawbacks such as low thermal and mechanical properties. The goal of this work was to synthesize and characterize new synthetic talc in a gel form with different magnesium (Mg) and nickel (Ni) ratios in their chemical structure Si4(MgxNi1−x)3O10(OH)2 with 0 < x < 1 and to evaluate their influence on mechanical and thermal properties when used as filler in WPU matrix in order to obtain new nanocomposites as well. WPU/STMgxNiy nanocomposites were prepared by physical mixing and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and mechanical dynamic analysis (DMTA). Improvements in nanocomposites mechanical properties in relation to pristine WPU matrix were observed for samples with higher synthetic talc content. The variation of the amount of Mg and Ni in synthetic talc composition altered the storage and loss modules results being higher for nanocomposites obtained with synthetic talc samples with higher Ni content in their compositions. Tg varied according to synthetic talc content. Synthetic talc with different metal content in their composition changes WPU nanocomposites thermal and mechanical properties. These fillers can be used to design nanocomposites with desired applications.