Hakimah Osman
Thumbnail Image
Preferred name
Hakimah Osman
Official Name
Hakimah, Osman
Alternative Name
Osman, Hakimah
Osman, H.
Main Affiliation
Scopus Author ID
7005733143
Researcher ID
AAT-9920-2020

Research Output

Filters

5
2
5
Reset filters

Settings
Now showing 1 - 5 of 5
  • Publication
    Effect of sulphur vulcanization system on physical, morphological and thermal properties of natural rubber latex foam
    ( 2022-05-18)
    Mohammad Syahrin Smail
    ;
    Zunaida Zakaria
    ;
    Hakimah Osman
    ;
    Syarifah Nuraqmar Syed Mahamud
    ;
    Munusamy Y.
    Recently, several research studies have been implemented using sodium bicarbonate (NaHCO3) as a blowing agent on rubber foams, yet none has been found in natural rubber latex foam (NRLF). The use of NaHCO3 as a blowing agent in NRLF prepared by the Dunlop process can potentially develop greener foaming processes and more environmentally friendly foam in the industry of latex foam. This novel method is designed to manage the reduction of harmful waste disposal associated typically in producing the NRLF product which is useful for industry purposes. Hence, this research is presented to investigate the physical properties of NRLF such as relative foam density, crosslink density, average cell diameter, and thermogravimetric analysis (TGA) based on the influences of different sulphur vulcanization systems via conventional vulcanization (CV) system and efficient vulcanization (EV) system. The relative density and crosslink density were increased with an increase in NaHCO3 concentration with the CV system exhibiting higher value than the EV system. For average cell diameter, the results showed a decrease in both systems with the EV system having higher value than the CV system. Thermal stability from the TGA results was also improved at higher NaHCO3 concentration and for the use of the CV system as a foaming approach, the CV system has higher thermal stability than the EV system.
      1
  • Publication
    Effect of blowing agent on compression and morphological properties of natural rubber latex foam
    ( 2020-09-21)
    Syahrin S.M.
    ;
    Zunaida Zakaria
    ;
    Hakimah Osman
    ;
    Syarifah Nuraqmar Syed Mahamud
    Sodium bicarbonate (NaHCO3) was used as a blowing agent in natural rubber latex foam (NRLF) in this study. At fixed vulcanization temperature and time in an air-circulating oven, the NRLF was prepared via the Dunlop method by whipping until frothing and adding NaHCO3 in latex compounds with different loading (i.e., 0, 3, 9 and 12 phr). An alternative formulation for the inclusion of NaHCO3 in NRLF was used. The effect of different blowing agent loading on the physical characteristics of NRFL such as relative foam density was investigated. Observation of cell diameter was performed using an optical microscope (OM). The result of NRLF's compression strength was also evaluated, which correlated with the foam's physical characteristics. The relative foam density was increased with an increase in the amount of NaHCO3. However, the average cell diameter was shown to decrease as the loading of the blowing agent increased. The outcomes of the NRLF's compression strength were also enhanced as the loading of the blowing agent increased following the physical characteristics of the foam respectively.
      7  6
  • Publication
    Recycled polyethylene terephthalate blends and composites: Impact of pet waste, engineering design, and their applications
    ( 2023-09-23)
    Zunaida Zakaria
    ;
    Hakimah Osman
    ;
    Nor Azura Abdul Rahim
    ;
    Munusamy Y.
    ;
    Ismail H.
    Polyethylene terephthalate (PET) is one of the major polymers produced and has been widely used in downstream industries, such as the production of textile fibers, packaging bottles, and films. The increased use of PET is associated with its excellent properties, which include thermal resistance, lightweight, high transparency, good impact, and relatively low cost. This indirectly contributes to a large amount of PET solid waste, which is detrimental to human life and exacerbates environmental issues. As a result, conversion to new PET blends and composites is an efficient method to recycle PET and reduce waste. While research in this area is ongoing and improving with the development of new materials for various applications, its commercialization has yet to begin. This chapter focuses on the designation of recycled PET and its performance as new blends and composites. Among the other topics discussed are PET waste sources, recycling methods, and applications, as well as the challenges of recycling PET and converting this solid waste into value-added products. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.
      1
  • Publication
    Effect of Activating Agent on Porous Activated Carbon in Alginate Macrobeads for Removal of Remazol Red Dye
    ( 2024-06-07)
    Zakir N.I.M.
    ;
    Zunaida Zakaria
    ;
    Hakimah Osman
    ;
    Hafiza Shukor
    ;
    Masa A.
    Alginate macrobeads filled with porous activated carbon (PAC) treated using different types of chemical activating agents were prepared in this study. Rice husk ash (RHA) was treated using five types of chemicals, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), zinc chloride (ZnCl2), hydrochloric acid (HCl) and citric acid, at a low temperature (~80°C) for 2 hours to produce PAC with high porosity and compared to the conventional process using furnace with a high processing temperature. A biopolymer, namely sodium alginate, was used to hold the PAC powder to produce an immobilized structure of PAC in macrobeads form. Adsorption of remazol red (RR) dye using macrobeads was measured using UV-spectrophotometer, while the morphology and composition of PAC were observed using scanning electron microscope (SEM) and energy dispersive X-ray (EDX), respectively. The functional groups of PAC were identified using attenuated total reflection Fourier transform infrared (ATR-FTIR). The results indicated that the alkali treated PAC successfully removed up to ~99% of the dye in 120 minutes, while the acid treated PAC could only remove ~30% the dye at the same time. This demonstrated that alkaline treatment produced PAC with higher porosity structure and the PAC produced using NaOH has high adsorption of RR dye.
      1
  • Publication
    Effect of Different Foaming Temperature on Properties of NaHCO3 – Natural Rubber Latex Foam
    ( 2023-01-01)
    Smail M.S.
    ;
    Zunaida Zakaria
    ;
    Hakimah Osman
    ;
    Masa A.
    ;
    Leemsuthep A.
    High volatile fatty acid natural rubber latex foam (H-VFA NRLF) was prepared via the Dunlop process using sodium bicarbonate, NaHCO3 as the blowing agent. The influence of different foaming temperatures (140 ℃, 150 ℃, 160 ℃, 170 ℃, and 180 ℃) on relative foam density, average cell size, cell size distribution frequency and compression stress-strain of H-VFA NRLF were studied. The average cell sizes were related to the relative foam density of H-VFA NRLF. As the temperature increased, the relative foam density increased, and eventually the average cell size decreased due to high amount of gas generated by blowing agents simultaneously. Meanwhile, smaller cell sizes were distributed as the temperature increased. It was found that the optimum temperature for H-VFA NRLF was 150 ℃ due to the lowest relative foam density and significantly larger uniform cell size were produced. Thus, the lowest compression stress up to 60% of strain was found at 150 ℃ and increased with increasing temperature. The mechanical properties were correlated with the morphology and physical properties of the H-VFA NRLF, respectively.
      1