Comparison of the clay minerals type on the properties of reinforced-PVA nanocomposites

The aim of this study is to determine and compare the effect of the clay minerals in a clay–polymer nanocomposite concerning the mechanical and thermal properties. The effects of the different clay minerals on different polymers have been researched frequently, but the comparison of the clay minerals was never studied. Since clay minerals have different properties from each other such as surface area, crystal structure, and surface properties, the effect of the clay minerals on the nanocomposites would be different. In this study, montmorillonite (Mt), vermiculite (Verm), and sepiolite (Sep) clay minerals were used to prepare the nanocomposites for the comparison. A basic polymer, polyvinyl alcohol (PVA), was chosen as the polymer and the basic method, solution-casting method, was used to prepare the nanocomposites. The structural and morphological characterizations were examined using X-ray diffraction, transmission electron microscopy, and Fourier transform infrared techniques, and mechanical and thermal properties of the nanocomposites were determined by dynamical mechanical analysis, and differential scanning calorimetry methods. The results showed that the layered clay minerals Mt and Verm can be dispersed well in the polymer and improved the mechanical and thermal properties more than the fibrous Sep. The bigger surface area of Verm lead to higher values of the elastic modulus, while the more interaction between Mt and PVA lead to higher values of glass temperature. POLYM. COMPOS., 38:1698–1704, 2017.