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31.
Mohd Basyaruddin Abdul Rahman Noraini Abdul Ghani Nik Ghazali Nik Salleh Mahiran Basri Raja Noor Zaliha Abdul Rahman Abu Bakar Salleh 《Journal of Coatings Technology and Research》2011,8(2):229-236
Of late, UV-curable products are gaining attention in the wood industry because of the effectiveness and efficiency of this method. UV-curable surface coatings are widely used because of their excellent properties and because they are environmentally friendly products. In this study, immobilized Candida antarctica lipase B was used to catalyze formation of liquid wax esters, such as adipate esters, via a solvent-free process. The adipate esters formed were then used as UV-curable reactants in the wood coating formulations, consisting of epoxy acrylate, additives, and a photoinitiator. The performance of the products was evaluated by coating them onto glass tiles (using gel content, hardness, and scratch resistance tests) and wood panels (using adhesion, impact, and heat resistance tests). The coated film from this formulation performed well during the evaluation tests. The gel content exhibited more than 90% polymerization, while the pendulum hardness gave a value of 55.25%. Both analyses were significant in determining the effect of irradiation cycles. A scratch test was also carried out to verify the resistance of the coating. The maximum weight load which can be resisted by the wax esters formulation is 4.5 N. 相似文献
32.
Elham Sobhanzadeh Nor Kartini Abu Bakar Mhd Radzi Bin Abas Keivan Nemati 《European Journal of Lipid Science and Technology》2011,113(7):862-869
This work reports a simple, rapid, and effective extraction method based on liquid–liquid extraction (LLE) followed by matrix solid‐phase dispersion‐sonication for detection, identification and quantification of multiclass pesticides in virgin olive oil using liquid chromatography mass spectrometry (LC‐QTOF‐MS). LLE to extract pesticide residues in virgin olive oil was performed in order to study the centrifugation efficiency to obtain high recovery yield and low co‐extract fat residue in the final extract. Different suitable parameters of MSPD procedure were evaluated, such as nature of dispersing phase, clean‐up adsorbent, and volume of eluting solvent (acetonitrile) in different extraction conditions, with or without sonication. The best results were obtained using 5 g of virgin olive oil, 2 g of PSA as dispersant sorbent, 2 g of Florisil/GCB (70:30 w/w) as clean‐up sorbent, and 15 mL of acetonitrile as eluting solvent under conditions of 15 min ultrasonic bath at RT. Method validation was performed in order to study sensitivity, linearity, precision, and accuracy. Average recoveries ranged between 73.7 and 104.2% with relative SDs 5.3–13.4% at three concentration levels (25, 50, and 100 µg/kg). Detection and quantification limits ranged from 1.5 to 5 µg/kg and 3 to 9 µg/kg, respectively. 相似文献
33.
34.
The effect of different processing routes on structure and properties of high‐density polyethylene (HDPE)‐clay nanocomposites was assessed. Different compatibilizer/clay ratios (α) were also studied to determine if interactions exist between processing route and polymer‐clay compatibility. HDPE/HDPE‐g‐MA/clay with α values of 1 to 4 were melt compounded (twin screw extrusion), and then processed via three routes: compression moulding, compression moulding followed by biaxial stretching or blown film extrusion. The structure was examined using X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile and oxygen barrier properties were determined. It was found that biaxial extensional forming produced the best enhancement in properties. An interaction between processing route and polymer‐clay compatibility is evident. Halpin‐Tsai (H‐T) model was employed to predict relative modulus values. It showed good agreement with the experimental data. For biaxial extension at α = 4.0, the experimental relative modulus is greater than the predicted value. This may indicate the existence of a “nano” effect at the polymer‐clay interface. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
35.
Ahmed Y. Musa Abu Bakar Mohamad Abdul Amir H. Kadhum Mohd Sobri Takriff Waleed Ahmoda 《Journal of Industrial and Engineering Chemistry》2012,18(1):551-555
Quantum chemical calculations were performed on ten thio compounds using semi-empirical method PM3 within program package of Material Studio 5.5. The effect of molecular structure on the corrosion inhibition efficiency was investigated using the quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, (LUMO–HOMO) energy gap, dipole moment (λ) and fraction of electron transfer (ΔN) were calculated and discussed. A relationship between the corrosion inhibition efficiency and several quantum parameters was established with coefficient correlation (R2) of 0.8894. 相似文献
36.
Chun Fah Mok Yern Chee Ching Noor Azuan Abu Osman Farina Muhamad Mohd Usman Mohd Junaidi Jia H. Choo 《应用聚合物科学杂志》2020,137(35):49044
In the quest on improving composite formulations for environmental sustainability, maleic acid (MA) cross-linked poly(vinyl alcohol) (PVA)-α-chitin composites reinforced by oil palm empty fruit bunch fibers (OPEFB)-derived nanocellulose crystals (NCC) had been successfully prepared. Based on the Fourier transform infrared (FTIR) spectroscopic analysis, it was proven that molecular interactions of the cross-linker to the polymeric networks was through conjugated ester linkage. Differential scanning calorimetry (DSC) showed that the influence of MA was minimal toward crystallization in the PVA/chitin/NCC composite. Maximum tensile strength, elongation at break and Young's modulus of the respective PVA/chitin/NCC composites were achieved at different content of MA, dependent on the PVA/chitin mass ratio. Among all compositions, a maximum Young's modulus was achieved at 30 wt% MA loading in PVA/chitin-30/NCC, amounting to 2,413.81 ± 167.36 MPa. Moreover, the mechanical properties and selected physicochemical properties (swelling, gel content, and contact angle) of the PVA/chitin/NCC composites could be tailored by varying the chitin content (10–30 wt%) and MA content (10–50 wt% based on total mass of composite). In brief, this chemically cross-linked PVA-based biocomposites formulated with sustainable resources exhibited tunable physicochemical and mechanical properties. 相似文献
37.
Sayuri L. Higashi Normazida Rozi Sharina Abu Hanifah Masato Ikeda 《International journal of molecular sciences》2020,21(24)
Supramolecular architectures that are built artificially from biomolecules, such as nucleic acids or peptides, with structural hierarchical orders ranging from the molecular to nano-scales have attracted increased attention in molecular science research fields. The engineering of nanostructures with such biomolecule-based supramolecular architectures could offer an opportunity for the development of biocompatible supramolecular (nano)materials. In this review, we highlighted a variety of supramolecular architectures that were assembled from both nucleic acids and peptides through the non-covalent interactions between them or the covalently conjugated molecular hybrids between them. 相似文献
38.
Hisham A. Essawy Ahmed S. Badran Abu El-Fetoh A. Abd El-Hakim Ahmed M. Youssef 《Polymer-Plastics Technology and Engineering》2013,52(1):66-71
Kaolinite was intercalated with N-methylformamide (NMF) and dimethylsulphoxide (DMSO), separately. The intercalation of these species expanded the basal space of kaolinite from 0.72 to 1.08 and 1.13 nm, respectively as shown by the X-ray diffraction (XRD). Emulsion polymerization of vinylacetate (VAc) was carried out at different temperatures (60–80°C) using acetone sodium bisulfite as initiator in the absence and presence of untreated as well as the modified forrms of kaolinite (K-NMF, K-DMSO). The results revealed that the presence of kaolinite decreased the rate of polymerization (Rp) by factor of 4 at 60 and 70°C and 7 at 80°C and also the activation energy of polymerization (E a ) was decreased from 43.35 × 104 to 10.32 × 104 J mole?1 if compared with the polymerization of VAc in absence of kaolinite. Using the modified forms of kaolinite (K-NMF, K-DMSO) enhanced the Rp and reduced effectively the E a to ? 27.92 and ? 55.78, respectively. Conversely to untreated kaolinite, the Rp was declining with increasing the temperature in these cases. In all cases, Rp was the highest in the absence of any kaolinite form but in the same time the E a was also the highest. These results were discussed and explained on the basis of the catalytic activity of the different forms, radical scavenging nature of the kaolinite, and chain transfer. 相似文献
39.
Aznizam Abu Bakar Norfhairna Baharulrazi 《Polymer-Plastics Technology and Engineering》2013,52(10):1072-1079
The influence of untreated and benzoylated oil palm empty fruit bunch (OPEFB) short fiber loading on the mechanical properties of the poly(vinyl chloride) (PVC) composite was studied. Benzoylated OPEFB was produced by mixing OPEFB with NaOH solution and agitating vigorously with benzoyl chloride. The PVC resin, various additives, and OPEFB were first dry blended using a laboratory mixer before being milled into sheets on a two-roll mill at 165°C and then hot pressed into composite samples at 180°C. The tensile and impact strength of untreated and benzoylated OPEFB composites decreased whereas the tensile modulus increased with increasing fiber loading from 0 to 40 phr. However, the benzoylated OPEFB was able to improve the tensile properties and impact strength of composites when compared to the untreated fiber. The enhancement of mechanical properties showed that the treatment improved the OPEFB fiber-PVC matrix interfacial adhesion. The improvement of adhesion was clarified by SEM micrographs, the increase of water resistance, and the reduction of glass transition temperature of the composites. 相似文献
40.
Ooi Xian Zhong Nor Aziah Abdul Aziz Azhar Abu Bakar 《Polymer-Plastics Technology and Engineering》2013,52(7):705-711
In this study, two different types of tropical fruit waste flour, rambutan waste flour (RWF) and banana waste flour (BWF), were blended with polyvinyl alcohol (PVOH) by solution casting method. The structure of the blend film was characterised by Fourier Transform Infrared Spectroscopy. The tensile strength and elongation at break of tropical fruit waste flour-filled polyvinyl alcohol were lower, but the tensile modulus was higher, than that of PVOH film. At a similar blend ratio, the tensile properties of the PVOH/RWF film were higher than the PVOH/BWF film, but the PVOH/BWF film showed higher water uptake than PVOH/RWF film. 相似文献