Now showing 1 - 10 of 63
  • Publication
    Effects of sodium hydroxide treatment on date seeds reinforced LLDPE composites: FTIR and gel content analyses
    ( 2020-03-25)
    Elnaid A.
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    ;
    Omar S. Dahham
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    Azizan M.A.
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    ;
    Dahham S.S.
    ;
    Umar M.U.
    The biocomposites from linear low-density polyethylene (LLDPE) and date seeds (DS) were successfully synthesized using extrusion and injuction molding process respectively. The effects of different Sodium Hydroxide (NaOH) concentration (3, 6, and 9 wt.%) on the structural properties of LLDPE/DS composites were invistigated using FTIR and Gel Content test. Results showed that a decrease on the absorption band at 3346 - 3347 cm-1 of treated samples as compared with untreated sample due to the removal of the hemicellulose component from the treated samples. Furthermore, the peak at 1050 cm-1 has slightly reduced as the NaOH added. The gel content of the treated samples have slightly increased as compared with LLDPE control, which means the number of crosslinks between LLDPE and DS increased in presence of NaOH. Furthermore, The treated sample with 6 wt.% NaOH showed relatively higher gel content compared to untreated sample and other treated samples.
  • Publication
    Investigation on the flexural properties of nanofillers loading on the Jute/Carbon/PLA nanocomposites
    ( 2020)
    Nur Aqilah Sairy
    ;
    Norkhairunnisa Mazlan
    ;
    Mohamad Ridzwan Ishak
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    Presence of fibers and fillers in a composite can be an efficient way to arrest crack either at macro or micro levels. In this work, woven jute and carbon fibers were arranged alternately in PLA (Polylactic Acid) nanocomposite. Graphene or nanoclay was embedded into PLA matrix to make polymer nanocomposite. Fiber reinforced polymer nanocomposites were prepared by varying the concentration of graphene or nanoclay in the PLA matrix and alternate woven jute/carbon fibers was then bind with the PLA nanocomposite. Influence of graphene or nanoclay concentration and presence of woven fibres in the composite was quantified by flexural analysis. Flexural strength and flexural modulus were found to increase at 3wt% of nanofiller concentration for both graphene/jute/PLA and nanoclay/jute/PLA nanocomposites with increment up to 37% and 31%, respectively. FTIR was used to determine the interaction between PLA and nanofillers. Morphology observation by Scanning Electron Microscopy (SEM) was done to investigate the fractured surface of the hybrid jute/carbon fibres reinforced PLA nanocomposite.
  • Publication
    Flexural and morphology properties of rHDPE/BF composites: effect of surface modification of bamboo filler by NaOH treatment
    (AIP Publishing, 2020)
    Aini Asifa Ahmad Kamal
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    ; ; ;
    Omar S. Dahham
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    N. A. Latip
    ;
    M. U. Umar
    This study is about the effect of alkaline treatment on bamboo filler reinforced with recycle high density polyethylene (rHDPE) composites. The alkaline treatment was done by sodium hydroxide (NaOH) at three different concentrations (2.5 wt.%, 5.0 wt.% and 7.5 wt.%) for two hours at room temperature. The bamboo filler and rHDPE was compound with the extrusion method and the granule was form. The granule of rHDPE/bamboo filler composites was inject by using injection molding to produce the sample of end product. The samples of rHDPE/bamboo filler was tested using conventional universal testing machine. Field emission electron microscopy (FESEM) was used to analyze the morphology of filler and Fourier Transform Infrared Spectroscopy (FTIR) for characterization of functional group in the filler and composites. The result showed that the flexural properties of rHDPE/bamboo filler composites were slightly affected by the alkaline treatment on the bamboo filler.
  • Publication
    Copper alloy reinforced by graphene by powder metallurgy technique
    (AIP Publishing, 2020)
    M. Yusoff
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    Mohamad M.
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    M. B. Abu Bakar
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    M. N. Masri
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    ;
    Omar S. Dahham
    ;
    M. U. Umar
    In this study, the effect of milling speed and compaction pressure on the densification and morphology of CuZn-Gr composite was evaluated. The composite was prepared by using powder metallurgy technique. The effect of the microstructural and compaction were determined based on different milling speed in thus research. The different milling speeds that involved were 175 rpm, 200 rpm, 225 rpm, and 250 rpm. Meanwhile, the different compaction pressures that used in this study were 127.53, 250, 374.67, and 500 MPa. The properties of the milled powder gave the result to green density and densification parameter. The peak XRD of Cu and Zn broadened as milling time increased. The milled powder at 250 rpm has lowest crystallite size and highest internal strain. As the milling speed is increase, the pattern of powder mixture diminished and become smaller due to the well homogenizing powders during milling. Besides, after compaction, 200 rpm and 250 rpm have optimum green density and densification parameter with increasing compaction pressure.
  • Publication
    Current method on spalling repair work in ages building
    (AIP Publishing, 2020)
    N. A. Latip
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    M. U. Umar
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    ;
    Izwan Johari
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    Omar S. Dahham
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    ;
    Shahrizal Nazri
  • Publication
    Mechanical and physical properties of non-woven kenaf fibre mat reinforced polypropylene composites prepared by compression molding
    (AIP Publishing, 2020)
    N. H. Lokman
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    M. B. Abu Bakar
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    M. N. Masri
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    Mohamed Mazlan
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    Omar S. Dahham
    ;
    M. U. Umar
    In this research, the non-woven kenaf fibre mat reinforced polypropylene composites (NWKFMRPP) were fabricated by the compression moulding method with different layers of kenaf fibre (KF) mat. The pure polypropylene (PP) matrix was used to prepare the composites to serve as control. Two types of maleic anhydride grafted polypropylene (MAPP) coupling agent which is MAPP1 (Polybond 3200) and MAPP2 (Orevac CA100) also have been used to enhance the adhesion between fibre and matrix. Fourier transform infrared (FTIR) spectroscopy was used to characterize the chemical constituents in pure PP and the NWKFMRPP composites. Then, tensile and flexural test were used to determine the mechanical properties by using a universal testing machine (UTM). Water absorption and thickness swelling test were also been carried out to reveal the physical properties of pure PP and NWKFMRPP composites. Overall, the result shows that the increment in KF layers has given a significant improvement in modulus properties but at the expense of strength properties. Besides, the percentage of water absorption increased when the layer of KF increased. However, the presence of both MAPP1 and MAPP2 coupling agents successfully enhanced its mechanical and water absorption properties as a result of the improvement of the fibre-matrix adhesion between the KF and PP matrix.
  • Publication
    Effect of chemical treatment on mechanical and physical properties of non-woven kenaf fiber mat reinforced polypropylene biocomposites
    (AIP Publishing, 2020)
    M. N. I. Mohd Sabri
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    M. B. Abu Bakar
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    M. N. Masri
    ;
    Mohamad Mazlan
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    ;
    Omar S. Dahham
    ;
    M. U. Umar
    Kenaf fibre mat (KFM) reinforced polypropylene (PP) biocomposites have been prepared using sandwich structure and hot press moulding technique. To enhance the interfacial bonding between PP and kenaf fibre, KFM was chemically treated with two different chemicals which are 5% hydrogen peroxide and 2% silane. Fourier transform infrared (FTIR) was used to characterize the chemical constituents in both treated and untreated kenaf fibres. Universal tensile machine (UTM) was used to determine mechanical properties (tensile and flexural strength, tensile and flexural modulus) of both treated and untreated KFM-PP biocomposites. Water absorption test was also conducted in order to evaluate its water-resistance performance. The result shows that peroxide treatment demonstrated the highest performance in mechanical and water absorption properties compared to other chemical treatment. SEM morphological studies proved that almost all treated KFM showing good fibre-matrix interfacial adhesion which less fibre pull out, void and and small interface gap. Thus, the chemical treatment on KFM improved fibre-matrix adhesion, which also contributed to the enhancement of mechanical properties and physical properties compared to untreated KFM reinforced PP biocomposites.
  • Publication
    Bioprotein optimization from spent mushroom substrate for fish feed application
    (AIP Publishing, 2020) ;
    Z. Masyitah
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    ; ; ;
    Omar S. Dahham
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    Saad S. Dahham
    The utilization of spent mushroom substrate as potential substrate for bioprotein production is being explored in this study. The objectives of this study were to screen three different types of fungi in bioprotein production from spent mushroom substrate and to optimize the process condition of the best fungi for production of bioprotein by using Design Expert Software. In this present study, screening of three different strains; Aspergillus terreus UniMAP AA-1, Aspergillus niger (ATCC 16404) and Phanerochaete chrysosporium (ATCC 24725), was done for bioprotein production by solid state fermentation process. P. chrysosporium produced the highest amount of protein on the sixth day, with the amount of 0.3951 mg/mL. Optimization of two parameters; substrate concentration and inoculum size for the selected fungi, P. chrysosporium was done conducted by Response Surface Methodology (RSM): Central Composite Design (CCD) to investigate optimal condition of bioprotein production. The optimum condition for P. chrysosporium to produce bioprotein using SMS was achieved at 60% of substrate concentration and 15% (w/v) of inoculum size with maximum protein concentration of 0.3812 mg/mL.
  • Publication
    UV-visible performance of urea beads coated with banana peels bioplastic and epoxidized natural rubber
    (AIP Publishing, 2020)
    S. A. Abdul Shukor
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    ; ;
    Omar S. Dahham
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    N. A. Faris
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    Saad S. Dahham
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    Haliza Jaya
    This study describes UV-Visible (UV-Vis) performance of urea beads coated with banana peels bioplastics and epoxidized natural rubber (ENR-50). Both banana peels bioplastics and ENR-50 were used as coating materials to the urea beads. Three different type of salts which are NaCl, MgCl2 and MgSO4 with different concentrations was added to this coating materials to produce pores and later modify the release rate of urea. UV-Vis spectroscopy techniques was applied to study the performance of urea release rate. The results of 30 days release study indicate the performance of coating materials is depend on types and its salts concentration. The addition of 5 wt% of MgSO4 salt recorded lowest urea concentration at 3 mg/mL, followed by 15 wt% of NaCl at 4.4 mg/mL and 5 wt% of MgCl2 at 9 mg/mL respectively.
  • Publication
    The effects of different bamboo filler loading on HDPE/BF composites and rHDPE/BF composites: flexural and morphology
    (AIP Publishing, 2020)
    Aini Asifa Ahmad Kamal
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    ; ; ;
    Omar S. Dahham
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    M. U. Umar
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    Izwan Johari
    In this article, wood plastic composite (WPC) is a composite material made up from bamboo as filler (BF) and high-density polyethylene and recycle high density polyethylene (HDPE) plastic as matrix. This research was conducted in order to investigate the mechanical properties of HDPE/BF and rHDPE/BF composites with different filler loading (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.%). From the morphology test by using Field Emission Scanning Electron Microscopy (FESEM), the bonding between filler and matrix to 10 wt.% show a positive effect and have a great bonding. The, Fourier Transform Infrared Spectroscopy (FTIR) used to analyze the functional group in the bamboo filler which contain lignin, cellulose and hemicellulose. The flexural test was conducted to study the mechanical properties of rHDPE/BF composites. Based on the flexural test result, the HDPE/BF and rHDPE/BF composites with 10 wt.% BF show the highest flexural result as decreasing filler loading will reduce the strength of the composites.