Now showing 1 - 10 of 17
  • 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
    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
    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
    ;
    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
    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
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    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
    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
    Surface modification of bamboo filler by acid treatment on flexural and morphology rHDPE/BF composites
    (AIP Publishing, 2020)
    Aini Asifa Ahmad Kamal
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    ; ; ;
    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.
      9  1
  • Publication
    Influence of filler surface modification on static and dynamic mechanical responses of rice husk reinforced linear low-density polyethylene composites
    Filler surface modification has become an essential approach to improve the compatibility problem between natural fillers and polymer matrices. However, there is limited work that concerns on this particular effect under dynamic loading conditions. Therefore, in this study, both untreated and treated low linear density polyethylene/rice husk composites were tested under static (0.001 s–1, 0.01 s–1 and 0.1 s–1) and dynamic loading rates (650 s–1, 900 s–1 and 1100 s–1) using universal testing machine and split Hopkinson pressure bar equipment, respectively. Rice husk filler was modified using silane coupling agents at four different concentrations (1, 3, 5 and 7% weight percentage of silane) at room temperature. This surface modification was experimentally proven by Fourier transform infrared and Field emission scanning electron microscopy. Results show that strength properties, stiffness properties and yield behaviour of treated composites were higher than untreated composites. Among the treated composites, the 5% silane weight percentage composite shows the optimum mechanical properties. Besides, the rate of sensitivity of both untreated and treated composites also shows great dependency on strain rate sensitivity with increasing strain rate. On the other hand, the thermal activation volume shows contrary trend. For fracture surface analysis, the results show that the treated LLDPE/RH composites experienced less permanent deformation as compared to untreated LLDPE/RH composites. Besides, at dynamic loading, the fracture surface analysis of the treated composites showed good attachment between RH and LLDPE.
      1  16
  • Publication
    Influence of filler surface modification on static and dynamic mechanical responses of rice husk reinforced linear low-density polyethylene composites
    Filler surface modification has become an essential approach to improve the compatibility problem between natural fillers and polymer matrices. However, there is limited work that concerns on this particular effect under dynamic loading conditions. Therefore, in this study, both untreated and treated low linear density polyethylene/rice husk composites were tested under static (0.001 s-1, 0.01 s-1and 0.1 s-1) and dynamic loading rates (650 s-1, 900 s-1and 1100 s-1) using universal testing machine and split Hopkinson pressure bar equipment, respectively. Rice husk filler was modified using silane coupling agents at four different concentrations (1, 3, 5 and 7% weight percentage of silane) at room temperature. This surface modification was experimentally proven by Fourier transform infrared and Field emission scanning electron microscopy. Results show that strength properties, stiffness properties and yield behaviour of treated composites were higher than untreated composites. Among the treated composites, the 5% silane weight percentage composite shows the optimum mechanical properties. Besides, the rate of sensitivity of both untreated and treated composites also shows great dependency on strain rate sensitivity with increasing strain rate. On the other hand, the thermal activation volume shows contrary trend. For fracture surface analysis, the results show that the treated LLDPE/RH composites experienced less permanent deformation as compared to untreated LLDPE/RH composites. Besides, at dynamic loading, the fracture surface analysis of the treated composites showed good attachment between RH and LLDPE.
      1
  • Publication
    The effects of ionic liquid (ILs) as additive on recycled high-density polyethylene reinforced bamboo filler composites
    (AIP Publishing, 2020)
    Aini Asifa Ahmad Kamal
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    ; ; ;
    Omar S. Dahham
    ;
    N. A. Latip
    ;
    M. U. Umar
    The study aim to improve the mechanical properties of recycled high density polyethylene (rHDPE) reinforced with bamboo filler (BF) by incorporating support of ionic liquids (ILs). The rHDPE/BF composites were produced by using injection molding process with different types of ILs in imidazolium based at three concentrations which is 0.2, 0.4 and 0.6 wt.%. The rHDPE/BF with ILs was compound with twin-screw extruder and undergoes injection molding process. The effects of ILs were characterized for mechanical, chemical and morphological properties of composites using tensile test, fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscope (FESEM). The results indicated that mechanical properties of the composites were improved by addition of ILs as additive. From the FTIR spectroscopy test, the presences of ILs were detected in the composites as it will improve the properties of composites. Finally, FESEM of fractured surface revealed better adhesion between the filler and matrix with the presence of additives.
      2  6
  • Publication
    Insight on the structural aspect of ENR-50/TiO2 hybrid in KOH/C3H8O medium revealed by NMR spectroscopy
    ( 2020-01-01)
    Dahham O.S.
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    Abu Bakar M.
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    Alakrach A.M.
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    ; ; ;
    Al-rashdi A.A.
    The ring-opening reactions (ROR) of epoxide groups in epoxidized natural rubber/titania (ENR-50/TiO2) hybrid in potassium hydroxide/isopropanol medium were examined using NMR spectroscopy and supported by the FTIR technique. The thermal behaviour of the hybrid was also studied using TG/DTG and DSC analyses. The 1H NMR results suggested that 16.82% of ROR occurred in the hybrid, while the 13C NMR results exhibited five new peaks at δ 19.5, 71.0, 73.7, 91.7 and 94.4 ppm in the hybrid. 2D NMR, such as HMQC, HMBC and COSY techniques, further scrutinized these assignments. The FTIR spectrum exhibited Ti-O-C characteristics via the peak at 1028 cm−1. The TG/DTG results showed four steps of thermal degradation at 44–148, 219–309, 331–489 and 629–810 °C due to the existence of Ti moieties along with a polymer chain mixture (intact and ring-opened epoxide groups) of ENR-50, which in turn led to an increase in the Tg value of the hybrid to 27 °C compared to that of purified ENR-50 at −17.72 °C.
      5  27