Abstract
M.Tech. (Chemistry)
Nanofillers and polymers are blended in an extruder using single pass or masterbatch (MB) dilution methods in order to address one of the major problems of dispersion with polymer nanocomposites. The mechanical properties of nanocomposites depend on the extent of homogeneous dispersion and distribution of nanoclays. This study used polypropylene (PP) as a model polymer owing to its unique toughness and modulus to investigate the melt processing strategies for preparing nanocomposites using a twin screw extruder (TSE). The TSE used has a screw diameter of 30 mm and L/D of 40 to produce nanocomposites with the following barrel temperatures: 120, 160, 180, 180, 180, 180, 180, 180, and 170 °C, respectively, while the die was set at 185 °C. PP nanocomposites were prepared through two main processes: MB dilution where MB with ~ 31 wt% inorganic nanoclay content was diluted further in PP to achieve 3 wt% inorganic nanoclay content in the nanocomposite; and direct preparation of composites through the single-pass method of compounding all the components that were mixed in an extruder at once. The extrudates were dried overnight at 80 °C to remove moisture from the samples. Dried extrudates were then injection moulded into test specimens for mechanical, rheological, and morphological tests using the Engel E-mac 50 injection moulder. The profile temperatures were set at 36, 220, 230, 235, 240 °C, respectively, and the mould was set at 17 °C. The effects of using different strategies on the dispersion of nanoclay platelets in the PP matrix were studied with transmission electron microscopy (TEM), X-ray diffraction (XRD), and small angle X-ray scattering (SAXS). TEM images show that the samples prepared via the MB...