Mohd Hafiz Zainol
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Preferred name
Mohd Hafiz Zainol
Official Name
Mohd Hafiz, Zainol
Alternative Name
Mohd, H. Z.
Zainol, Mohd
Zainol, M. H.
Main Affiliation
Scopus Author ID
57201736993
Researcher ID
CGX-4416-2022

Research Output
Now showing 1 - 2 of 2
  • Publication
    Effect of multi-walled carbon nanotubes reinforcement on self-healing performance of natural rubber
    ( 2024-01-01)
    Mohd Sani N.F.
    ;
    Shuib R.K.
    ;
    Mohd Hafiz Zainol
    ;
    Othman N.
    ;
    Tran D.L.
    This work is motivated by the desire to restore the quality of rubber-based product properties with the intention of prolonging the service life period, thus helping create a sustainable environment by proposing effective rubber waste management. This study experimentally investigated an intrinsically self-healing zinc thiolate grafted natural rubber (NRZT) compound filled with multi-walled carbon nanotubes (MWCNT) to assess its influence on mechanical properties and self-healing performance. The MWCNT loading varied to 0, 2, 4, 6, and 8 phr. The Equilibrium swelling test was used to quantify the amount of ionic and covalent crosslinks formed. Fourier Transform Infrared (FTIR) spectra were used to detect the presence of MWCNT in the compound. The mechanical properties computed by the tensile and tear strength tests showed that the incorporation of MWCNT increased both properties up to three and twofold, respectively. However, as expected, the elongation at break (Eb) value was reduced. The unfilled sample showed that it can heal up to ∼98 %, measured from the tensile strength. However, the healing efficiency obtained from tensile strength reduces to ∼88 % by incorporating 2 phr MWCNT. The Eb and its self-healing efficiency gradually decreased as the MWCNT amount increased. All samples showed outstanding properties under the tearing mode, where the healed samples produced higher tear strength (>100 % healing) than the initial value. Scanning Electron Microscopy (SEM) micrographs revealed a noticeable gap along the healed cut line with increased MWCNT numbers, possibly due to the lower reaction between polymerized zinc thiolate (PZTh) radicals with zinc thiolate (ZT) and rubber molecules. The work aims to investigate the influence of MWCNTs on the mechanical and healing performance of self-healing NR composites by comparing them to their unfilled sample.
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  • Publication
    Investigation on recycling and reprocessing ability of self-healing natural rubber based on ionic crosslink network
    (De Gruyter Brill, 2024)
    Mohd Hafiz Zainol
    ;
    Raa Khimi Shuib
    ;
    Ismail Ibrahim
    ;
    Fairul Sharin Abd Razak
    ;
    Noor Faezah Mohd Sani
    ;
    Trans Dai Lam
    Natural rubber (NR) is a complex material that is often discarded due to its three-dimensional structure. Recycling of rubber is difficult due to its complex structure, and only 1.7 million tonnes of waste, such as tyres and gloves, are considered recyclable. This study aims to develop self-healing rubber, which allows a product to recover without affecting structural reliability. Commercial NR was ionically crosslinked with zinc thiolate, forming an ionic crosslink network between rubber chains and zinc thiolate ions. The ionic crosslinks allow the rearrangement of rubber molecular chains under external heat, providing self-healing capabilities. The highest ionic crosslink density was found in NR with 35 phr zinc thiolate. The self-healing NR can recover 90 % of its initial properties at room temperature for 10 min and can be reprocessed and recycled three times without compromising its properties. It also shows excellent weldability, making it a promising material for repairing existing rubber products in heavy engineering applications.