عنوان مقاله [English]
Hypothesis: Polymer nanocomposites have found enormous applications owing to superior physical and mechanical properties such as modulus, strength and barrier behaviour, etc. Contrary to polymer microcomposites, polymer nanocomposites benefit from lower density and being less problematic in processing. In this study, nanocomposites of polyolefin elastomer (POE)/nanosilicon carbide (SiC) and polyolefin elastomer/nanoclay with different percentages of nanoparticles were prepared using melt mixing method in the presence of vinyltriethoxy silane as interfacial modifier.
Methods: Nanocomposite samples were prepared in a Brabender internal mixer using a roller mixing equipment. The fill factor was selected as 0.75. The mixing was carried out at a speed of 60 rpm at 120°C. The resulting nanocomposites were then subjected to various tests to investigate their physical, mechanical and rheological properties.
Findings: Sheet-like nanoclay particles have higher aspect ratio compared to spherical nanoSiC particles. Nevertheless, the results indicated that POE/SiC nanocomposites had higher tensile strength and elongation-at-break compared to nanoclay-reinforced composites. This was attributed to higher interactive efficiency between SiC nanoparticles and POE matrix. The moduli of nanocomposites at similar content of nanoparticles showed the same values regardless of the type of nanoparticles. Higher rheological properties were observed for nanoclay nanocomposites, though; the amount of increase was lower than those reported in literature. Morphology investigations of SiC and clay nanocomposites exhibited a comparable degree of dispersion of nanoparticles for both types of nanocomposites at similar compositions. Thermal properties of nanocomposites were studied by thermogravimetric analysis and differential scanning calorimetry. The results showed that the melting temperature and degree of crystallinity of both types of nanocomposites decreased with increasing nanoparticles content; however, the observed decrement was higher for POE/SiC nanocomposites. Thermal stability of POE/clay nanocomposites was higher, which could be attributed to the nanoparticle geometry.