Now showing 1 - 10 of 25
  • 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
    ;
    ; ; ;
    Omar S. Dahham
    ;
    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
    Current method on spalling repair work in ages building
    (AIP Publishing, 2020)
    N. A. Latip
    ;
    M. U. Umar
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    ;
    Izwan Johari
    ;
    Omar S. Dahham
    ;
    ;
    Shahrizal Nazri
  • 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
    ;
    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
    ;
    ; ; ;
    Omar S. Dahham
    ;
    M. U. Umar
    ;
    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.
  • Publication
    Sawdust short fiber reinforced epoxidized natural rubber: insight on its mechanical, physical, and thermal aspects
    (Tech Science Press, 2020)
    O. S. Dahham
    ;
    ;
    Haliza Jaya
    ;
    ;
    M. U. Umar
    ;
    I. Johari
    In this work, Epoxidized natural rubber/sawdust short fiber (ENR-50/ SD) composites at different fiber content (5, 10, 15 and 20 phr) and size (fine size at 60–100 μm and coarse size at 10–20 mm) were prepared using two-roll mill and electrical-hydraulic hot press machine respectively. Curing characteristics, water uptake, tensile, morphological, physical, and thermal properties of the composites were investigated. Results indicated that the scorch time and cure time became shorter whereas torque improved as SD content increase. Though the decline of tensile strength and elongation at break values, modulus, hardness and crosslinking density have shown enhancements with the increasing of SD content. The water uptake percentage of all samples has shown an increasing as SD content increase. However, the low SD content, particularly fine size have presented lower water uptake. The temperature of weight% loss (5 and 50 wt% loss) of 5 phr SD (low content) have recorded higher temperature compared to 20 phr SD (high content) in the rubber composites, which indicated higher thermal stability. The fine size of SD has recorded better overall properties than SD coarse size at same loading in the rubber composites.
  • Publication
    Tailoring polylactic acid properties for packaging applications: effects of co‐addition of halloysite nanotubes and selected plasticizers
    (Trans Tech Publications Ltd., 2020)
    Abdulkader M. Alakrach
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    ;
    Awad A. Al-Rashdi
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    ;
    Omar S. Dahham
    ;
    Polylactic acid (PLA) has recently given a huge attention because of its mechanical properties and good physical like good biodegradability and processability, high tensile modulus and strength. In the current research, the researchers utilized sesame oil (SO) and low molecular weight polyethylene glycol (PEG) as hydrophobic and hydrophilic plasticizers, towards improvise the ductility and toughness of PLA. The researchers synthesized nanocomposites by solution casting of the neat PLA/HNTs and PLA blends with weight ratio of (0,10, 20 and 30 wt%) for PEG and (0, 5 and 10 wt%) for SO. The influence of both plasticizers on chemical, thermal and mechanical properties of the nanocomposites were investigated. Characterization of the systems was achieved by mechanical testing and thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR). The FTIR analyses confirmed the existing of hydrogen bonding between PLA and both PEG and SO. significant improvement was shown by the plasticized nanocomposites in elongation at break with the adding of PEG and SO, meanwhile, the plasticized films’ strength were decreased. For the thermal analyses, all the films exhibited lower thermal stability compared to PLA/HNTs film.
  • Publication
    PLA/MMT-TiO₂ bionanocomposites: chemical structure and surface wettability
    (Trans Tech Publications Ltd., 2020-01)
    Luqman I. Alrawi
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    ;
    Mohamed K. Alomar
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    Abdulkader M. Alakrach
    ;
    Omar Sabbar Dahham
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    ;
    Bashir O. Betar
    ;
    Taha M. Jassam
    Polylactic Acid (PLA) has been used widely in packaging application because of its biodegradability. The aim of this study is to produce PLA nanocomposites by solvent casting incorporating montmorillonite nanoclays (MMT) and titanium dioxide (TiO₂) nanoparticles. The effect of different loadings of MMT in PLA and different loadings of TiO₂ on chemical structure and surface wettability were studied. The nanocomposites were prepared by solvent casting at different loadings of MMT (0, 2, 4, 6 wt %) and different loadings of TiO₂ (1 and 3 wt %) respectively. The chemical structure and surface wettability were determined. The absorption peaks in the range of 3550-3200 cm-1 had increased after incorporating of TiO₂ and it indicated that there is the presence of stretching vibration of O-H groups. Moreover, increasing the percentage of TiO₂ mass in the nanocomposites decreased the contact angle with water which led to increasing the wettability of the nanocomposites.
  • Publication
    Properties of natural rubber/ethylene propylene diene monomer/recycled latex catheter (NR/EPDM/rLC) ternary blends: Cure characteristics and hardness
    Currently, the recycled rubber widely being used in rubber technology. Due to difficulty on reprocessing techniques, the vulcanized rubbers being a big problem in the recycled field. One of the main forms of discharge rubber is to apply as fuel to generate electricity and steam, this process is still in use but creates a new problem of air pollution and is also a low value to recovery process of the rubber waste [. Polymer compounds are being used extensively in numerous applications such as roofing and mulch product. A rubber blends can offer a better properties that gives high performance in application area that being used
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  • Publication
    The influence of alkali treatment on date seeds powder reinforced LLDPE composites: Flexural properties and impact strength
    ( 2020-03-25)
    Elnaid A.
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    ;
    Dahham O.S.
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    ; ; ;
    Umar M.U.
    In this work, the influences of different concentration of sodium hydroxide (NaOH) (3, 6 and 9 wt.%) on the flexural and impact properties of linear low-density polyethylene / date seeds (LLDPE/DS) composites were examined. The LLDPE / DS ratio was fixed at 90/10 wt.% and the size of DS particles was measured at 125 - 250 micro m. The process used to synthesize the composites id extrusion followed by injuction molding process. Results showed that the presence of NaOH particularly at 6 wt.% concentration has improved the flexural and impact properties of the composite. This is due to bonding of the date seeds particles with the LLDPE matrix that reflected posativelly on the mechanical properties of the composite. However, the using of high NaOH concentration (9 wt.%) has shown an opposite trend, the increasing of surface roughness of the fiber after 9% NaOH treatment has reduced the flexibility of the composite and made it stiffer and more rigid, which in turn made it easy to break during mechanical test.
      4  35
  • Publication
    Surface modification of bamboo filler by acid treatment on flexural and morphology rHDPE/BF composites
    (AIP Publishing, 2020)
    Aini Asifa Ahmad Kamal
    ;
    ; ; ;
    Omar S. Dahham
    ;
    M. U. Umar
    ;
    Izwan Johari
    This study main objective is to compare the effect of different concentration on surface treatments of natural fibrous material, bamboo filler (BF) by using acetic acid (CH3COOH). The application of surface treatment on natural fibrous material can improve the compatibility with polymer matrix material. Different concentration on surface treatment by using CH3COOH were applied at 0 wt.%, 2.5 wt.%, 5.0 wt.% and 7.5 wt.%. After the application of surface treatments, the fibrous materials were combined with polymer matrix material, particularly recycled high density polyethylene (rHDPE), by twin screw extruder and injection moulding. The mechanical test was performed to evaluate the influence of different concentration of surface treatments on rHDPE/BF composites. The experimental results shows that the surface treatment by using CH3COOH on BF strongly affect the mechanical properties of the final composite materials by increasing the flexural strength ultimately at 5.0 wt.% concentration CH3COOH with the highest flexural strength. The morphology of treated BF by using Field Emission Scanning Electron Microscope (FESEM) show that the lignin, wax and other impurities was removed from BF.
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