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Browsing Conference Publications by browse.metadata.impactarea "Advanced Polymer Composites"
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Item Analytical techniques to quantify modifiers in bitumen for the South African asphalt pavement industry(2021-07) Makhari, A; Hawes, Nomashaka BN; Mturi, George AJ; Ojijo, Vincent OModifying bitumen is currently a common practice in South Africa. The asphalt pavement industry has seen an increase in use of different types of modifiers in an attempt to improve or extend the properties of bitumen. Common modifiers used in South Africa include plastomers (e.g. ethylene vinyl acetate or EVA), elastomers (e.g. styrene-butadiene-styrene or SBS) and warm mix additives (e.g. waxes). Bitumens are already complex materials which can be represented mechanically and rheologically with mathematical models. Recently, the need to also characterise the in situ structural and chemistry effect of modifiers within bitumen has been appreciated, in order to determine their influence on modified bitumen performance. This paper explores the analysis of bitumen with various modifiers using Fourier Transform Infra-Red (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC). Special attention is paid to quantification of these modifiers in bitumen as a quality control and forensic investigative tool, due to the current asphalt failure challenges facing the industry. The aim is to accurately determine the extent of modification through analytical techniques as a monitoring tool for the better construction of asphalt pavement roads. The paper shows such analytical scientific techniques have the potential to quantify locally used modifiers in South African bitumen.Item Qualitative assessment on the surfactant traces from the organically modified nanoclay containing polymer nanocomposite(2020-11) Khoza, Mary; Sinha Roy, Jayita; Ray, Suprakas S; Ojijo, Vincent OTraces of quaternary ammonium salt from dispersed nanoclay in PA6/6.6 polymer nanocomposite may have some potential toxicological effects that could pose a risk to human health. Modified nanocomposite system was produced by masterbatch melt extrusion process while water-assisted nanocomposite was prepared via direct melt extrusion process. Investigations were conducted by hyphenated thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA-FTIR). Small traces of surfactant alkyl ammonium ions in the nanocomposite can be found in the masterbatch and nanocomposite.Item The thermal degradation kinetics and morphology of poly(vinyl butyral) cast films prepared using different organic solvents(2020-11) Motlatle, Abesach M; Bothloko, Orebotse J; Scriba, Manfred R; Ojijo, Vincent O; Ray, Suprakas SPolyvinyl butyral (PVB) films are highly promising materials as they combine interesting thermal and structural morphology properties and in many cases coating viability. However, the polymerization ability of PVB films through solvent casting method using different solvents is fundamentally not well understood. In this rational, the present study demonstrates the use of Isopropanol, ethanol, methanol, and acetic acid for the development of high quality PVB films. The resulting acetic acid-based PVB film exhibits moderated thermal stability with smooth surface morphology which is an important factor in coating applications. On the other hand, ethanol-based PVB film achieves higher thermal stability relative to all other PVB films with some structural defects attributed to less impurities in the solvents. This study will pave the development of high performance PVB cast films.Item Thermal properties and nonisothermal crystallization behaviour of polypropylene nanocomposite(2020-11) Bandyopadhyay, Jayita; Mekoa, Raphaale C; Skosana, Sifiso; Ray, Suprakas SNucleated polypropylene (PP) masterbatch and the nanoclay-containing composite of PP are prepared by reactive processing method to improve the thermo-mechanical properties of virgin PP. PP masterbatch and the nanocomposite exhibits pronounced improvement in crystallization temperature (Tc) and the heat distortion temperature (HDT) when compared with neat PP. The melting and nonisothermal crystallization behaviors of the neat PP and the nanocomposite are studied by differential scanning calorimetry. Results indicate that half time of crystallization at a particular cooling rate remains unchanged in neat PP and the nanocomposite. However, super cooling effect is pronounced in the nanocomposite when compared with neat PP. Irrespective of cooling rate there is approximately 14% improvement in Tc in PP nanocomposite with respect the neat PP. Such an improvement in Tc with improved thermo-mechanical properties are highly desirable for rigid packaging.