Enhanced thermal and mechanical properties in polyurethane/Au nanocomposites

We have prepared waterborne polyurethane (WBPU) thin films containing gold nanoparticles by casting WBPU/Au solutions. The effect of the Au nanoparticle contents on the microstructure and properties of the composite films was investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electronmicroscopy (FESTM), transmittance electron microscopy (TEM), FTIR spectroscopy (FTIR) and dynamic mechanical analysis (DMA). The Au nanoparticles initially in the WBPU solution were well dispersed in the WBPU films cast and dried at 60 degreesC. The thermostability and mechanical properties of the polymer increased with Au contents up to 4.35 x 10(-2) wt.-%, which was believed to be a result of induced crystallization in the presence of Au nanoparticles. The Au/WBPU nanocomposite containing with 6.5 x 10(-2) wt.-% of Au resulted in the aggregation of Au particles, which leads to a worsening of the thermal and mechanical properties.