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Effect of Chemically Modified Banana Fibers on the Mechanical Properties of Poly-Dimethyl-Siloxane-Based Composites
(Journal of Materials and Engineering Structures, 2019-05-18) Danyuo, Yiporo; Zakariyyah, Taiwao; Nasiru, Suleman; Mustapha, Kabiru; Azeko, Tahiru S.; Bello, Sefiu A.; Abade-Abugre, Miriam; Yirijor, John; Anyidoho, Victor; McBAGONLURI, Fred
The study presents the mechanical properties of polymer-based composites reinforced with chemically modified banana fibers, by alkalization in different concentrations of sodium hydroxide (NaOH). The fiber weight fraction has a great effect on the mechanical properties of the composites. Stiff composites were obtained at 6 wt% fiber fractions with Young’s modulus of 254.00 ±12.70 MPa. Moreover, the yield strength was 35.70 ±1.79 MPa at 6 wt% fiber fractions. However, the ultimate tensile strength (UTS) and toughness of the composites were obtained at 5 wt% fiber fractions. Statistical analyses were used to ascertain the significant different on the mechanical properties of the fibers and composites. The implication of the results is then discussed for potential applications of PDMS-based composites reinforced with chemically modified banana fibers.
Effects of fibre reinforcements on properties of extruded alkali activated earthen building materials
(2019-12-10) Emeso B. Ojo; Kabirat O. Bello; Kabiru Mustapha; Ronaldo S. Teixeira; Sérgio F. Santos; Holmer Savastano
The reaction between clay minerals present in soil and an alkaline solution has the potential to develop in situ binders, which can be harnessed in the development of earth based construction materials. To ascertain the efficacy of this stabilisation mechanism in conjunction with fibres which are commonly used in earthen construction, this study presents a comparative analysis of the reinforcing effect of different fibre types (sisal, Eucalyptus pulp microfibers and polypropylene) in an alkali activated stabilised soil produced using extrusion technique. An evaluation of flexural properties in oven-dry and saturated conditions was conducted to simulate mechanical response in ideal and extreme conditions to evaluate effect of fibre type and content (0–2 vol%). Physical properties were also studied and optimum fibre contents evaluated. Results show that with respect to lignocellulosic fibres, sisal fibre reinforcements yielded the most remarkable result with the highest statistically significant improvement in flexural strength (79% relative to the unreinforced matrix) compared to composites reinforced with Eucalyptus pulp micro-fibres. Improved packing density and attendant reduction in water absorption associated with sisal fibre reinforced composites was attributed to synergistic interactions between sisal fibres and alkali activated matrix. On the other hand, synthetic fibre reinforcement (polypropylene), which had no statistically significant effect on composite flexural strength, transformed brittle unreinforced matrices to deflection hardening composites due to weak fibre-matrix interactions. Sisal fibres have thereby demonstrated a significant reinforcing potential in extruded alkali activated earth-based materials and presents a satisfactory balance of strength, density and ductility for the development of eco-friendly building materials for low cost housing solutions.
Kinetics of the Antioxidant Activities of Solanum macrocapon and Crassocephalum rubens by DPPH Radical Scavenging Method
(Journal of Chemical Society of Nigeria, 2020-02-11) Yusuff, K. O.; Omotosho, K.; Mustapha, K.; Abdulraheem, A. M. O.
Solanum macrocapon (S.macrocapon) and Crassocephalum rubens (C.rubens) was investigated. The methanolic extracts of the samples were tested with 2,2-diphenyl-1-picrylhydrazyl (DPPH) at different times (30, 50, 70 and 90 minutes). UV-Visible Spectroscopy technique was employed Â to evaluate the ability of the plant extracts to scavenge DPPH radicals by measuring the absorbance at the various experimental times. The concentration of sample required to inhibit 50% of the DPPH free radical (IC50) and kinetic parameter (rate constant k2) were determined from the absorbances values. S.macrocapon and C.rubens had DPPH scavenging potency with IC50Â values of 2.18 x 10-2 mgml-1Â and 6.27 x 10-2Â mgml-1Â respectively. This implied that S.macrocapon is a more potent antioxidant than C.rubens. The rate constant for the hydrogen atom abstraction by DPPH (k2) in the presence of S.macrocapon is 2.70 x 10-3Â Â± 0.0006 mlmg-Â 1min-1Â with R2Â value of 0.709 while for C.rubens, the rate constant is 6.89 x 10-4Â Â± 0.03 x 10-4 mlmg-1min-1Â with R2Â value of 0.987 using Pseudo-first order kinetics model. However, under second order kinetics, the rate constant, k2, for S.macrocapon is 4.73 x 10-1Â Â± 0.020 mM-1min-1Â with R2Â value of 0.993 while C.rubens has k2 value of 5.55 x 10-2 Â± 0.00236 mM-1min-1Â with R2Â value of 0.795. Thus, the depletion of DPPH by S.macrocapon followed a second order kinetics while that of C.rubens followed a Pseudo first order kinetics.Â Keywords: Kinetics, DPPH, Antioxidant, UV-Vis spectroscopy, IC50Â
Mechanical performance of fiber-reinforced alkali activated un-calcined earth-based composites
(2020) Emeso B. Ojo; Kabirat O. Bello; Odette F. Ngasoh; Tido T. Stanislas; Kabiru Mustapha; Holmer Savastano; Wole Soboyejo
This paper presents the results of a multi-scale study of the mechanical properties of model earth-based composites. The composites are produced by the alkali activation of in-situ clay minerals within an earthbased matrix that is reinforced with two different ﬁbers (sisal and polypropylene). The local mechanical properties of the ﬁbers, binder and matrix materials are characterized at the nano- and micro-scales using nano-indentation and statistical deconvolution techniques. The macro-mechanical properties are also elucidated using a combination of ﬂexural strength testing, and resistance-curve experiments. The underlying strengthening and toughening mechanisms are explored using a combination of in-situ/exsitu observations and micro-mechanical models. The implications of the results are then discussed for the design of strengthened and toughened earth-based composites that are reinforced with natural ﬁbers (such as sisal) and synthetic ﬁbers (such as polypropylene ﬁbers).
Mechanical properties of calcium carbonate/eggshell particle filled polypropylene Composites
(MRS Advances, 2020) Kabiru Mustapha; Rashidat Ayinla; Abdulraman Sikiru Ottan; Tunji Adetayo Owoseni
Calcium carbonate is widely used as a filler material in the production of polymer matrix composites and studies have shown that eggshell contains about 94% calcium carbonate. The effect of calcium carbonate from eggshell particles in polypropylene was studied in this work and the result compared with unreinforced polypropylene. Industrially synthesized calcium carbonate/eggshell particles were used as filler in polypropylene matrix with varying mass fractions from 5 to 20 wt. % at 5 wt. % increment. The produced samples were mechanically characterized for indentation hardness and uniaxial tensile properties using a Rockwell hardness tester and universal mechanical testing machine respectively. These properties were measured at different compositions to determine its compositional dependence. Microstructural analysis of the composites top and fracture surface was also carried out using scanning electron microscope to examine possible failure mode. The results were compared to measure the effect of reinforcement and the replacement criteria for the conventional calcium carbonate. The results obtained showed that calcium carbonate reinforced polypropylene has its highest tensile strength, elastic modulus and modulus of rupture at 5 wt. %, ductility and modulus of resilience at 10 wt. %, and hardness at 15 wt. %. The results also showed that granulated eggshell can provided appreciable improvement in the mechanical properties of polypropylene as obtainable in mineral calcium carbonate reinforced polypropylene.
Mechanical Properties, Durability and Microstructure of Palm Kernel Shell Concrete Produced from Different Grades of Portland Limestone Cement
(Nigerian Research Journal of Engineering and Environmental Sciences, 2024-06-30) Odeyemi, S. O.; Adegolu, E.R.; Adisa, M.O; Atoyebi, O.D; Mustapha, K.; Adeniyi, A.G.
The need for lightweight structures and to reduce environmental waste which leads to pollution has necessitated the utilization of agro-based materials as aggregates for concrete. Notable among these wastes is the Palm Kernel Shell (PKS). This study investigated the compressive and tensile strength, durability and internal structure of PKS concrete made with 32.5N and 42.5N grades of Portland Limestone Cement (PLC). A designed mix of Grade 20 culminating into a combined ratio of 1:1:1 for cement, sand and PKS batched by volume adopting a water-cement ratio (w/c) of 0.45. The compressive and tensile strengths of the concrete were tested, the durability of the concrete was determined using a water absorption test and Scanning Electron Microscopy (SEM) was conducted to correlate the test results. The outcome of investigations showed that PKS concrete from the cement of grade 42.5N has higher compressive and tensile strengths than grade 32.5N. Microstructural images from SEM showed non-uniformly distributed voids which are higher in concrete produced from 32.5N grade cement. Hence, the PKS concrete from grade 32.5N PLC absorbed more water than the concrete made from 42.5N PLC. Therefore, cement grade affects the strength, durability and microstructure of PKS concrete.
OPTIMIZATION AND MODELLING OF BIO-OIL YIELD FROM THE PYROLYSIS OF JATROPHA CURCAS SEED USING OPTIMAL DESIGN AND ARTIFICIAL NEURAL NETWORKS
(LAUTECH Journal of Engineering and Technology, 2023-07-27) K. O. Oladosu; T. O. Amoloye; K. Mustapha; J. O. Oderinde; S. Babalola
Better quality and quantity of pyrolysis products from biomass can be obtained by regulating the input parameters of the pyrolysis process. Pyrolysis of Jatropha Curcas seed mixed with alumina catalyst was carried out in a fixed bed reactor to study the effects of temperature, time, and particle size on bio char and bio-oil yield. The bio-oil yields were optimized using the Optimal Design (OD) under the Combined Methodology of the Design-Expert Software (12.0). The input and output parameters were modeled and validated using Artificial Neural Networks (ANN) based on 40 experimental data generated by the OD. The optimum bio-oil yield of 15.6 wt. % was obtained at 650 °C, 30 min, and 1 mm particle size. The Correlation Coefficient (R2) of the model for the bio-char and bio-oil yield under the OD were 0.998 and 0.996, respectively. The optimized ANN architecture employed the in-built Levenberg-Marquardt training algorithm in MATLAB software. Random division of the data into training, validation and testing sets followed 70:15:15 percentage proportions with 15 hidden layers. This resulted in the minimum Mean Square Error (MSE) of 2.15e-05 and (R2) of 0.96394 for the bio-oil yield. The FTIR spectra indicated that bio-oil contained phenols, esters, and acids compound while its Gas Chromatography analysis showed the presence of pyrrolidine, pyrimidine, and aldehydes. These properties signified the bioenergy and biochemical capabilities of the pyrolytic oil obtained. The prediction accuracy indicates that both the ANN and OD can be deployed for accurate prediction.
Reinforcement of cement mortar with recycled polyethylene waste for construction applications
(2021) Moses K Flomo; Salifu T Azeko; Emmanuel K Arthur; Jamal-Deen Kukurah; Kabiru Mustapha; Ebenezer Annan; Benjamin Agyei-Tuffour
This current research work combines both experimental and theoretical study of the impact of cement mortar reinforced with recycled polyethylene waste for applications in the construction industry. The work explores incorporating low density polyethylene (LDPE) waste into cement mortar to improve its fracture toughness and flexural strength with balanced compressive strength. Different volume fractions (0, 5, 10, 15, 20, 30, and 40%) of the powdered LDPE were mixed with cement and the density, compressive strength, flexural strength, and the fracture toughness were observed under different testing conditions. All specimens were tested after curing of 7, 14, and 28 days. The results show that there was [Formula: see text]6% increase in the fracture toughness at 5 vol. %, [Formula: see text]7% increase at 10 vol. %, and 24% increases at 20 vol. % of LDPE. Also, it was observed that the weight and compressive strength decreased with increasing volume fraction up to 40 vol. % of LDPE waste. The results for the survival/failure probability show that the PE-mortar composites with PE volume percentages up to 20 vol. % had the highest survival probability. The composite with this volume percentage can withstand crack up to 6 mm, with a survival probability of 0.6.
Strength and fracture resistance of cellulose fiber reinforced cement composite
(2022-07-26) Mustapha, Kabiru; Sogoye, Michael; Abdulraman, Sikiru Ottan; Danyuo, Yiporo; Tahiru, Azeko Salifu; Annan, Ebenezer
This study presents the production and experimental assessment of the strengths and fracture resistance of cellulose fiber-reinforced cementitious composite material. The composite, which consists of mixture of recycled fibers obtained from waste carton boxes, was stabilized with measured level of Ordinary Portland Cement. The effects of constituent’s composition on compressive strength, flexural strength and fracture toughness were elucidated. Compressive strengths and flexural strengths were measured using uniaxial compressive and three-point bend loading conditions respectively while a single edge notch bend test (SENB) condition was employed for the fracture toughness measurement. The results obtained from experiments showed that the composite properties are significantly improved by the fiber reinforcement with optimum properties obtained at fiber composition of 5wt. % with compressive strength of 24.4 MPa, flexural strength of 8.0 MPa and fracture toughness of 1.36 MPa√m. The results were discussed for possible applications of robust cellulose fiber reinforced cement composite materials suitable for interior structural applications and to provide potential opportunities for waste management and/or recycling of carton boxes and other related wastes.
Theoretical modeling of flow for frustum - shaped ceramic water filters via disc-shaped ceramic water filters
(ARPN Journal of Engineering and Applied Sciences, 2019-12-24) Bensah, Yaw Delali; Damoah, Lucas N. W.; Nyankson, Emmanuel; Yaya, Abu; Nukpezah, Daniel; Azeko, Salifu Tahiru; Mustapha, Kabiru; Annan, Ebenezer
In the past two decades, research on household technologies has been on the increase. Ceramic water filters are simple and appropriate technology proven to have capability to provide improved drinking water especially in rural and peri-urban communities. These filters can be fabricated into various shapes with careful consideration of their mechanical robustness. This paper gives an overview of various flow models in estimating flow rate for ceramic water filters, in particular frustum-shaped ceramic water filters. Analytical approach to estimate the quantity of water considering the geometrical shapes; frustum and cylindrical shapes of the Ceramic water filters are adopted. The analytical expressions deduced for the flows are applicable on the assumption that the materials used in the fabrication of the filters are the same, thus same material properties (chemical and thermal properties) and porosimetry characteristics. Also, the comparative flow equation is largely dependent on dimensions of the ceramic water filters. The scholarly articles on flow through ceramic water filters for frustum-shaped filter are theoretically explored.
Uniaxial tensile response of coconut coir fiber-reinforced polyethylene Composites
(2019) Mustapha, Kabiru; Bello, Sefiu Adekunle; Danyuo, Yiporo; Oshifowora, Tobi
The roles of Composite materials in a variety of engineering applications have increased due to their enhanced strength and modulus, especially polymer-based composites which is one of the commercially available composites. The uniaxial tensile properties of polyethylene matrix reinforced with coconut coir fibers has been studied and the results from experiments and analytical models are presented. The compositional dependence of tensile strength, stiffness (elastic modulus), modulus of resilience and ductility are explored for different proportions of the constituent materials through experiments and analytical models. The results from experiments showed that the properties measured were greatly affected by the fiber mass fraction with optimized properties obtained at fiber content of 10 wt%.

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