Browsing by Author "Onuegbu, G. C."

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    Effect of filler loading and particle size on the mechanical properties of periwinkle shell-filled recycled polypropylene composite
    (U. P., 2017) Onuoha, C.; Onyemaobi, O. O.; Anyakwo, C. N.; Onuegbu, G. C.
    Mechanical properties of composites of recycled polypropylene filled with periwinkle shell powder were investigated. Periwinkle shells used in this study were thoroughly cleaned, ground and sieved to three particle sizes of 150, 300 and 425 µm respectively. Filler loadings of 0 to 25 wt% were used in compounding the composites in an injection moulding machine and the resulting composites were extruded as sheets. Some mechanical properties were determined. Results showed that periwinkle shell powder improved the tensile strength, flexural strength, tensile modulus and hardness of polypropylene composites. These properties were found to increase with filler loading up to 15 wt% or 20 wt% loading (optimal filler loading) but decrease with filler particle size. However, elongation at break was found to decrease with increasing filler loading. Highest tensile and flexural strengths were obtained at 15 and 20 wt% respectively at 150 µm particle size. It is therefore concluded that periwinkle shell powder is suitable for the production of polypropylene composites
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    Physical and morphological properties of periwinkle shell-filled recycled polypropylene composites
    (U. P., 2017) Onuoha, C.; Onyemaobi, O. O.; Anyakwo, C. N.; Onuegbu, G. C.
    Physical and morphological properties of periwinkle shell-filled recycled polypropylene composites were studied. Periwinkle shells used in this study were processed and sieved to three particle sizes of 150, 300 and 425 µm respectively. Filler loadings of 0 to 25 wt% were used in compounding the composites in an injection moulding machine and the resulting composites were extruded as sheets. Some physical and morphological properties were determined. Results showed that the incorporation of periwinkle shell powder into the recycled polypropylene matrix increased the specific gravity of the composites. Increase in filler loading resulted to increase in specific gravity probably due to enhanced dispersion of fillers. However, increase in filler particle size led to decreased specific gravity due to poor filler dispersion and consequent filler agglomeration. Water sorption was found to increase with increase in both filler loading and filler particle size due to the hydrophilic nature of the filler and enhanced porosity created by large particles. Flame propagation was found to decrease with increase in both filler loading and filler particle size due to the evolution of CO2 in the combustion process, which suppresses the burning rate. There was increase in solvent sorption with increase in both filler loading and filler particle size. It was also noticed that solvent sorption was most pronounced in benzene, followed by toluene and lastly xylene. This is in accordance with the order of closeness of their solubility parameters with that of polypropylene. Morphological analysis revealed enhanced spherulization and dispersion with smaller particle sizes but enlarged spherulization and consequent agglomeration at larger particles sizes. Based on these results, periwinkle shell can be considered suitable for the production of recycled polypropylene composites