Unsaturated polyester inorganic mineral nanocomposites preparation and properties

Abstract

The object of advanced polymeric materials is to be metal like; they need stiffness, toughness and high thermal stability. There is an increasing demand for advanced materials with better properties to meet new requirements or to replace existing materials. Nanocomposites are prepared using unsaturated polyester resin with nanoparticles of calcium carbonate/silica/alumina and zinc oxide by casting technique. The size of the nanoparticles and formation of the nanocomposites is investigated by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD) techniques. The structure of the nanocomposites is investigated by Fourier transform infrared spectroscopy (FT-IR). The influence of addition of different concentrations (1, 3, 5, 7 and 9 wt%) of inorganic nanoparticles into the UPR matrix on gel time, density, mechanical properties (tensile strength, modulus and elongation, flexural strength and modulus, impact and hardness) and the morphological properties (tensile and impact fracture) are studied. The mechanical and dynamic mechanical properties of the nanocomposites investigated increased up to optimum loading of nanoparticles in to the UPR matrix where as the thermal properties of the nanocomposites increased with increase of nanoparticles loading in the UPR matrix. This observation may be due to the fact that the incorporated inorganic nanoparticles possess high thermal stability by absorbing heat energy and by restricting the evolution of smaller fragments, since the introduction of nano fillers stiffens the matrix. Moreover in the present investigations, comparatively the higher mechanical and thermal properties are noted for UPR/silica nanocomposites. The smaller particle size of nano silica and its better miscibility with UPR matrix are may be the reason for these properties enhancement. The agglomeration and weak adhesion between nano fillers and matrix is the reason why the mechanical properties decreased beyond the optimum loading of nano particles into the UPR matrix. newline