Browsing by Author "Onukwuli, Okechukwu Dominic"

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    Influence of chemical surface modifications on mechanical properties of combretum dolichopetalum fibre-high density polyethylene (HDPE) composites
    (U. P., 2018) Azeez, Taofik Oladimeji; Onukwuli, Okechukwu Dominic; Walter, Peter Echeng; Menkiti, Mathew Chukwudi
    Maximizing the use of natural fibres as ecofriendly materials in polymer composite applications reduces its threat posed to human through increased biomass in the environment. In this study, the effect of chemical surface modifications using acetic anhydride and sodium hydroxide solution on the mechanical properties of Combretum dolichopetalum fibre-HDPE composites was aimed to be investigated. Fibres were treated with 6 % acetic anhydride and 12 % NaOH solutions for 30 minutes at room temperature based on optimum treatment conditions after water retting extraction process, then, the composites were prepared. The mechanical properties (tensile strength, tensile modulus, flexural strength, flexural modulus, hardness and impact strength) of the C. dolichopetalum fibre reinforced HDPE matrix composites and scanning electron microscope analysis were studied. C. dolichopetalum fibre was not only effective as reinforcement of HDPE matrix but mercerization and acetylation of C. dolichopetalum fibre ultimately enhanced the mechanical properties of HDPE composites. Scanning electron microscope analysis revealed that HDPE matrix possess better adhesive interaction with acetylated and mercerized C. dolichopetalum fibre compared with untreated C. dolichopetalum fibre at ultimate tensile strength.
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    Optimization and characterization of the properties of treated avocado wood flour-linear low density polyethylene composites
    (Elsevier B.V. on behalf of Faculty of Engineering, Alexandria University, 2019) Government, Rabboni Mike; Onukwuli, Okechukwu Dominic; Azeez, Taofik Oladimeji
    Abstract The research was carried out to investigate the optimization of surface modification for avocado wood flour (ACWF) and the characterization of the treated and untreated of avocado wood flour–linear low density polyethylene composite (ACWF-LLDPE). The variation of treated filler on the mechanical and water sorption properties was investigated. The untreated and treated ACWF-LLDPE composite was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Central Composite design of response surface model (RSM) was used to forecast the mechanical and water sorption properties of ACWF-LLDPE composite. The properties of ACWF-LLDPE composite was statistically analysed and found to be significant. The optimal treatment was particle size of 100 mesh and filler content of 22.97%. At optimum particle size and filler content, the mechanical properties were 24.972 MPa tensile strength (TS), 6.195% elongation (E), 0.863 GP a tensile modulus (TM), 62.664 MPa flexural strength (FS), 0.809 GP a flexural modulus (FM), 699.918 Pa Brinell hardness (BH), and 91.619 kJ/m2 impact strength (IM). The corresponding water sorption (WS) at this condition was 3.338%.