Mohd Firdaus Omar
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Preferred name
Mohd Firdaus Omar
Official Name
Mohd Firdaus, Omar
Alternative Name
Omar, Mohd Firdaus
Mohd, Firdaus Omar
Omar, M. F.
Omar, Mohdfirdaus
Omar, Mohd F.
Main Affiliation
Scopus Author ID
36149536300
Researcher ID
U-8459-2019

Research Output
Now showing 1 - 6 of 6
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Publication

Influence of filler surface modification on static and dynamic mechanical responses of rice husk reinforced linear low-density polyethylene composites

2021 , Mohd Firdaus Omar , Mohd. Mustafa Al Bakri Abdullah , Sam Sung Ting , B. Jeż , M. Nabiałek , Hazizan Md Akil , Nik Noriman Zulkepli , Shayfull Zamree Abd. Rahim , Azida Azmi

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.

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Publication

Effect of aluminium powder on kaolin-based geopolymer characteristic and removal of Cu²⁺

2021 , Nurliyana Ariffin , Mohd. Mustafa Al Bakri Abdullah , Przemysław Postawa , Shayfull Zamree Abd. Rahim , Mohd Remy Rozainy Mohd Arif Zainol , Ramadhansyah Putra Jaya , Agata Śliwa , Mohd Firdaus Omar , Jerzy J. Wysłocki , Katarzyna Błoch , Marcin Nabiałek

This current work focuses on the synthesis of geopolymer-based adsorbent which uses kaolin as a source material, mixed with alkali solution consisting of 10 M NaOH and Na2SiO3 as well as aluminium powder as a foaming agent. The experimental range for the aluminium powder was between 0.6, 0.8, 1.0 and 1.2wt%. The structure, properties and characterization of the geopolymer were examined using X-Ray Diffraction (XRD), Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Adsorption capacity and porosity were analysed based on various percentages of aluminium powder added. The results indicate that the use of aluminium powder exhibited a better pore size distribution and higher porosity, suggesting a better heavy metal removal. The maximum adsorption capacity of Cu2+ approached approximately 98%. The findings indicate that 0.8% aluminium powder was the optimal aluminium powder content for geopolymer adsorbent. The removal efficiency was affected by pH, adsorbent dosage and contact time. The optimum removal capacity of Cu2+ was obtained at pH 6 with 1.5 g geopolymer adsorbent and 4 h contact time. Therefore, it can be concluded that the increase in porosity increases the adsorption of Cu2+.

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Publication

Nonisothermal kinetic degradation of Hybrid CNT/Alumina Epoxy Nanocomposites

2021 , Muhammad Helmi Abdul Kudus , Muhammad Razlan Zakaria , Mohd Firdaus Omar , Muhammad Bisyrul Hafi Othman , Hazizan Md. Akil , Marcin Nabiałek , Bartłomiej Jeż , Mohd. Mustafa Al Bakri Abdullah

Due to the synergistic effect that occurs between CNTs and alumina, CNT/alumina hybrid-filled epoxy nanocomposites show significant enhancements in tensile properties, flexural properties, and thermal conductivity. This study is an extension of previously reported investigations into CNT/alumina epoxy nanocomposites. A series of epoxy composites with different CNT/alumina loadings were investigated with regard to their thermal-degradation kinetics and lifetime prediction. The thermal-degradation parameters were acquired via thermogravimetric analysis (TGA) in a nitrogen atmosphere. The degradation activation energy was determined using the Flynn–Wall–Ozawa (F-W-O) method for the chosen apparent activation energy. The Ea showed significant differences at α > 0.6, which indicate the role played by the CNT/alumina hybrid filler loading in the degradation behavior. From the calculations, the lifetime prediction at 5% mass loss decreased with an increase in the temperature service of nitrogen. The increase in the CNT/alumina hybrid loading revealed its contribution towards thermal degradation and stability. On average, a higher Ea was attributed to greater loadings of the CNT/alumina hybrid in the composites.

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Optimization of injection moulding process via Design Of Experiment (DOE) method based on Rice Husk (RH) Reinforced Low Density Polyethylene (LDPE) composite properties

2022 , Haliza Jaya , Nik Noriman Zulkepli , Mohd Firdaus Omar , Shayfull Zamree Abd. Rahim , Marcin Nabiałek , Kinga Jeż , Mohd. Mustafa Al Bakri Abdullah

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Optimization of injection moulding process via Design Of Experiment (DOE) method based on Rice Husk (RH) Reinforced Low Density Polyethylene (LDPE) composite properties

2021 , Haliza Jaya , Nik Noriman Zulkepli , Mohd Firdaus Omar , Shayfull Zamree Abd. Rahim , Marcin Nabiałek , Kinga Jeż , Mohd. Mustafa Al Bakri Abdullah

Optimal parameters setting of injection moulding (IM) machine critically effects productivity, quality, and cost production of end products in manufacturing industries. Previously, trial and error method were the most common method for the production engineers to meet the optimal process injection moulding parameter setting. Inappropriate injection moulding machine parameter settings can lead to poor production and quality of a product. Therefore, this study was purposefully carried out to overcome those uncertainty. This paper presents a statistical technique on the optimization of injection moulding process parameters through central composite design (CCD). In this study, an understanding of the injection moulding process and consequently its optimization is carried out by CCD based on three parameters (melt temperature, packing pressure, and cooling time) which influence the shrinkage and tensile strength of rice husk (RH) reinforced low density polyethylene (LDPE) composites. Statistical results and analysis are used to provide better interpretation of the experiment. The models are form from analysis of variance (ANOVA) method and the model passed the tests for normality and independence assumptions.

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Publication

Influence of filler surface modification on static and dynamic mechanical responses of rice husk reinforced linear low-density polyethylene composites

2021 , Mohd Firdaus Omar , Mohd. Mustafa Al Bakri Abdullah , Sam Sung Ting , B. Jeż , M. Nabiałek , Hazizan Md Akil , Nik Noriman Zulkepli , Shayfull Zamree Abd. Rahim , Azida Azmi

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.

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