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  1. Darfizzi Derawi
    Sains Malaysiana, 2016;45:1149-1154.
    Hydroxy-ether-POo
    was synthesised via alcoholysis reaction of epoxidized palm olein (EPOo
    ). The experimental design
    was conducted using response surface methodology (RSM) based on 3 factors; reaction time, reaction temperature and
    catalyst loading. Responses such as percentage of conversion and percentage of yield were determined using statistical
    software ‘Design Expert 9’. Hydroxy-ether-POo
    showed the presence of proton peak attached to the carbon of ether
    (3.2, 3.5 ppm) and proton of the hydroxyl (4.8 ppm). The presence of carbon peak bonded to hydroxyl was detected at
    chemical shift 75 ppm and carbonyl carbon of ether at 72 ppm.
  2. Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2011;40:1123-1127.
    Kajian pengoptimuman tindak balas pengepoksidaan minyak sawit olein (POo) dengan menggunakan mangkin asid performik (HCOOOH) telah dijalankan. Kesan tindak balas terhadap nisbah kepekatan HCOOH : H2O2 dan masa tindak balas telah dikaji pada suhu 45oC. Kandungan oksigen oksirana (OOC) optimum sebanyak 3.61% diperoleh dengan menggunakan nisbah mol 1 : 5 : 2 pada 150 min dan sebanyak 96.5% penukaran dapat dicapai. Hasil tindak balas adalah sebanyak 91.3%. Puncak kromatografi cecair berprestasi tinggi (HPLC) bagi minyak sawit olein terepoksida (EPOo) telah berubah sepenuhnya berbanding puncak HPLC POo. Spektrum transformasi Fourier infra-merah (FTIR) telah menunjukkan kehadiran puncak ikatan gelang oksirana pada 844 cm-1.
  3. Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2013;42:1121-1129.
    Sebatian poliol minyak sawit olein (di-hidroksi-POo) (70% hasil) disintesis melalui pembukaan gelang oksirana minyak sawit olein terepoksida (EPOo) secara hidrolisis selanjar dan berkelompok. Hasil optimum pembukaan gelang oksirana (97.2%) bagi kedua-dua tindak balas selama 90 min (tindak balas selanjar) dan 75 min (tindak balas berkelompok) dengan menggunakan mangkin asid perklorik 3% v/wt. Spektrum transformasi Fourier inframerah (FTIR) di-hidroksi-POo menunjukkan kehadiran puncak lebar getaran regangan kumpulan hidroksil pada nombor gelombang 3429 cm-1, menunjukkan sebatian poliol telah berjaya dihasilkan. Spektrum resonan magnetik nukleus-karbon (13C-NMR) di-hidroksi-POo telah menunjukkan kehadiran puncak karbon yang terikat dengan kumpulan hidroksil (74.5 ppm). Spektrum resonan magnetik nukleus-proton (1H-NMR) di-hidroksi-POo telah menunjukkan kehadiran puncak proton yang terikat pada karbon poliol (3.4 ppm) dan proton pada kumpulan hidroksil (4.6 ppm). Kelikatan kinematik produk poliol (nilai hidroksil sebanyak 110.7 mgKOH/g minyak) adalah 1435.2 cSt (40oC) dan 55.2 cSt (100oC) dengan indeks kelikatan 78.
  4. Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2016;45:817-823.
    Sebatian hidroksi-eter-POo
    (80% hasil) disintesis melalui pembukaan gelang oksirana minyak sawit olein terepoksida
    (EPOo
    ) secara alkoholisis. Hasil optimum pembukaan gelang oksirana (99.2%) dicapai dengan menggunakan asid
    sulfurik 3% v/bt pada suhu tindak balas yang tinggi (80o
    C) selama 30 minit masa tindak balas. Spektrum resonan
    magnetik nukleus-proton (1
    H-NMR) hidroksi-eter-POo
    telah menunjukkan kehadiran puncak proton pada karbon eter
    (3.2, 3.5 ppm) dan proton pada kumpulan hidroksil (4.8 ppm). Spektrum resonan magnetik nukleus-karbon (13C-NMR)
    hidroksi-eter-POo
    telah menunjukkan kehadiran puncak karbon yang terikat dengan kumpulan hidroksil (75 ppm) dan
    karbon pada karbonil kumpulan eter (72 ppm). Kelikatan kinematik hidroksi-eter-POo
    adalah 234.4 cSt (40o
    C) dan 28.1
    cSt (100o
    C) dengan indeks kelikatan 156.
  5. Nurazira Mohd Nor, Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2018;47:1359-1367.
    The epoxidation process of RBD palm oil was carried out using in situ generated performic acid. The effect of various
    process variables such as the formic acid towards hydrogen peroxide mole ratio, the reaction temperature and the
    reaction time were optimized by using response surface methodology (RSM). The D-optimal design was used to evaluate
    the influence of process variables and their interaction in order to obtain the process optimum conditions. The results
    showed that the optimum conditions of the epoxidation process were at 5.91 mole ratio of formic acid towards 3.60 mole
    of hydrogen peroxide, reaction temperature of 40ºC and reaction time of 2.55 h. At the optimum condition, the epoxidised
    RBD palm oil (EPO) yield was 86% with oxirane oxygen content (OOC) of 3.46%. The results showed in good agreement
    with the predicted values from the RSM model.
  6. Jumat Salimon, Waled Abdo Ahmed, Nadia Salih, Mohd Ambar Yarmo, Darfizzi Derawi
    Sains Malaysiana, 2015;44:405-412.
    Synthesis of new lubricants nowadays is increasing to improve the lubricity properties and the quality of lubricant. In
    the current study, eight diesters with different chemical structures were tested in terms of their suitability as lubricants.
    The esterification reaction was carried out using Dean-Stark distillation method with some modification. Fourier
    transformation infra-red (FTIR), proton and carbon nuclear magnetic resonance (1
    H-NMR and 13C-NMR), were used to
    verify the chemical structure of the diesters. The results showed that the dioleyl pimelate (DOlP), dioleyl adipate (DOlA),
    dioleyl glutarate (DOlG), and dioleyl succinate (DOlSuc) showed good low temperature properties with pour point values
    at -10, -12, -16 and -20°C, respectively. The dioleyl dodecanedioate (DOlD) indicated remarkable flash point value at
    305°C and had slightly high oxidative stability temperature (OT) at 183°C. The flash point increased with the number of
    carbons for dicarboxylic acid used, while oxidative stability was affected by the unsaturated of oleyl alcohol. Tribological
    study showed that the diesters were non-Newtonian except DOlD, which was Newtonian fluid. All the diesters were found
    to be boundary lubricants with low coefficients of friction (COF). Overall, the results indicated that all the diesters studied
    can be used as lubricating base oils.
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