Writers: Komatsu, Daniel; Paranhos, Caio Márcio; Ruvolo-Filho, Adhemar
Keywords: mechanical properties; nanocomposites; polyolefin; thermal properties; transmission electronic microscopy
Abstract: Nanocomposites of linear low density polyethylene (LLDPE)/montmorillonite clay were obtained by diluting a masterbatch, containing 20.0% clay, in a twin screw extruder to obtain samples with 1.5% to 10.0% clay. In this study was used the X-ray diffraction (XRD) technique to investigate the structure of montmorillonite clay and was observed that the clay present in the nanocomposites was disorganized. Scanning electron microscopy using a field emission gun (SEM-FEG), and transmission electron microscopy (TEM) showed that there was good distribution and good dispersion of the clay in the polymer matrix, resulting in intercalated and exfoliated structures, respectively. Regarding the mechanical properties, we observed a significant increase in elastic modulus and decrease in toughness for all clay concentrations. With the results from thermogravimetric analysis (TGA) it was observed that the sample with a concentration of 1.5% clay had the highest thermal stability and the sample with 10.0% was the least stable, thus demonstrating that there is a critical concentration of clay in relation to this property.
