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Nanocrystalline cellulose (NCC) extracted from lignocellulosic materials has been actively investigated as a drug delivery excipients due to its large surface area, high aspect ratio, and biodegradability. In this study, the... more
Nanocrystalline cellulose (NCC) extracted from lignocellulosic materials has been actively investigated as a drug delivery excipients due to its large surface area, high aspect ratio, and biodegradability. In this study, the hydrophobically modified NCC was used as a drug delivery excipient of hydrophobic drug curcumin. The modification of NCC with a cationic surfactant, cetyl trimethylammonium bromide (CTAB) was used to modulate the loading of hydrophobic drugs that would not normally bind to NCC. The FTIR, Elemental analysis, XRD, TGA, and TEM were used to confirm the modification of NCC with CTAB. The effect of concentration of CTAB on the binding efficiency of hydrophobic drug curcumin was investigated. The amounts of curcumin bound onto the CTAB-NCC nanoparticles were analyzed by UV-vis Spectrophotometric. The result showed that the modified CTAB-NCC bound a significant amount of curcumin, in a range from 80% to 96% curcumin added. Nevertheless, at higher concentration of CTAB resulted in lower binding efficiency.
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Cellulose nanocrystals (CNCs) from kenaf core were prepared using acid hydrolysis method while graphene oxide (GO) were synthesized from modified Hummer’s method. Low filler content composites films of CNC (0.1 – 0.4 wt.%) and GO (0.1 –... more
Cellulose nanocrystals (CNCs) from kenaf core were prepared using acid hydrolysis method while graphene oxide (GO) were synthesized from modified Hummer’s method. Low filler content composites films of CNC (0.1 – 0.4 wt.%) and GO (0.1 – 0.6 wt.%) in PLA films were prepared separately using solution casting method. From tensile test, it was found that optimum modulus increment were obtained for 0.2 wt.% CNCs and 0.4 wt.% GO in PLA which gave an increment of 125% and 40%, respectively. Only a small amount of CNCs are needed to improve the tensile properties of PLA. From microscopic observation of fractured surface at higher filler contents, CNC agglomerates tend to form which serves as void nucleating agent during plastic deformation due to poor interfacial properties while GO agglomerates cannot be observed in composites. Improved mechanical properties were not due to increment of crystallinity in PLA but reinforcement from fillers.
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ABSTRACT Unsaturated polyester resin (UPR) has been modified with a liquid epoxidized natural rubber (LENR). The addition of LENR improves the toughness, but it is inevitably accompanied by a significant loss in stiffness, yield strength,... more
ABSTRACT Unsaturated polyester resin (UPR) has been modified with a liquid epoxidized natural rubber (LENR). The addition of LENR improves the toughness, but it is inevitably accompanied by a significant loss in stiffness, yield strength, and thermal resistance. Incorporation of a rigid material into the LENR-UPR blend, such as cellulose nanocrystal (CNC), provided a ternary polyester nanocomposites with desire mechanical properties. In the present work, the effects of different CNC and LENR content on the nanocomposite morphology and mechanical properties were examined. Morphological studies revealed that the size of the rubber particles is independent of the rubber content due to the chemical interaction of rubber and matrix; however, the size of the LENR particles increased with increasing CNC content. Tensile tests indicated that the blend’s tensile strength and elastic modulus could be further improved by incorporation of the CNCs. The high crystallinity and surface area of CNCs were the main factors for improvement of tensile properties of the blend. Moreover, the impact energy of the UPR improved when it was modified with the LENR, and even further improvement was achieved with the CNC addition to form nanocomposites. Dynamic mechanical thermal analysis (DMTA) showed that the storage modulus of nanocomposites with 1.5 wt% rubber content was lower than those with 4.5 wt% LENR; however, both samples showed a higher storage modulus than the neat UPR and the unfilled blend. The glass transition temperature (Tg) of the UPR decreased with the LENR addition, but improved with the addition of CNCs. The nanocomposites prepared with a higher LENR content displayed better mechanical properties than those with low LENR content.
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ABSTRACT The effects of chemical treatment on aramid fibers have been studied in Twaron-ENR composite system using micromechanical and mechanical testing. Both untreated (HM) and treated with epoxy adhesion activation (HMA) aramid fibers... more
ABSTRACT The effects of chemical treatment on aramid fibers have been studied in Twaron-ENR composite system using micromechanical and mechanical testing. Both untreated (HM) and treated with epoxy adhesion activation (HMA) aramid fibers were bonded to ENR matrix. The adhesion between aramid fibers and Epoxidized Natural Rubber (ENR) was measured using microbond method. It was found that the interfacial shear strength (IFSS) between aramid fibers and ENR matrix has been improved for both HM and HMA fibers with the introducing of RFL treatment. The results obtained from microbond pull-out test seem to be agree with the effective mechanical properties of Twaron- ENR composite measured using tensile and impact tests. This behaviour was supported by scanning electron microscope analysis of the specimens following tensile testing. From the results it can be concluded that both epoxy adhesion activation and RFL coated fiber improved the interaction between the aramid fiber and ENR matrix.
ABSTRACT Toughened unsaturated polyester resins (UPRs) were prepared using two different reactive rubbers, namely, liquid natural rubber (LNR) and liquid epoxidized natural rubber (LENR). The effect of varying amounts of LNR and LENR on... more
ABSTRACT Toughened unsaturated polyester resins (UPRs) were prepared using two different reactive rubbers, namely, liquid natural rubber (LNR) and liquid epoxidized natural rubber (LENR). The effect of varying amounts of LNR and LENR on the morphology, thermal, and mechanical properties of UPR were evaluated. Fourier Transform Infrared spectroscopy was used to investigate the probable crosslinking reaction and changes in the functional groups on crosslinking. Field emission scanning electron microscopy and infinite focus microscopy were used to study the morphology of fracture surfaces. Tensile test showed that both the rubber-modified resins (1.5 wt %) improved tensile strength. The viscoelastic properties and thermal stability of the toughened polyesters were evaluated using dynamic mechanical thermal analysis and thermogravimetric analysis, respectively. A slight reduction in the glass transition temperature (Tg) of the polyester was reported on the addition of both the rubbers. An increment in impact strength and fracture toughness was observed at 1.5 wt % for LNR and 4.5 wt % for LENR-modified UPR. The results showed that both the liquid rubbers improved the mechanical properties of UPR. However, LENR-modified UPR exhibited a more significant improvement in the mechanical properties compared to LNR-modified UPR. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41292.
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Coconut fibers were used as reinforcement for unsaturated polyester resin from recycled PET that has been prepared using glycolysis and polyesterification reaction. Various concentrations of alkali, silane, and silane on alkalized fiber... more
Coconut fibers were used as reinforcement for unsaturated polyester resin from recycled PET that has been prepared using glycolysis and polyesterification reaction. Various concentrations of alkali, silane, and silane on alkalized fiber were applied and the optimum concentration of treatments was determined. Morphological and mechanical properties of the composite have also been investigated to study the effect of fiber surface treatment. The influence of water uptake on the sorption characteristics of composites was studied via immersion in distilled water at room temperature. Surface treatment of coconut fiber caused a significant increase in the tensile properties with the optimum treatment of 0.5% silane on the 5% alkalized coconut fiber/polyester composites. For water absorption study, it was observed that the treated fiber composites showed lower water absorption properties in comparison to those of untreated fiber composites. SEM investigation showed that the surface modifica...
Sifat mekanik termoplastik getah asli (TPNR) yang diperkuat gentian kaca tikar telah dikaji berfungsikan rawatan permukaan gentian kaca tikar menggunakan silana. TPNR yang digunakan adalah adunan polietilena berketumpatan tinggi (HDPE),... more
Sifat mekanik termoplastik getah asli (TPNR) yang diperkuat gentian kaca tikar telah dikaji berfungsikan rawatan permukaan gentian kaca tikar menggunakan silana. TPNR yang digunakan adalah adunan polietilena berketumpatan tinggi (HDPE), getah asli (NR) dan cecair getah asli (LNR) pada nisbah HDPE/NR/LNR 50:40:10 yang telah diadun menggunakan mesin pengadun dalam. Keputusan menunjukkan bahawa agen pengkupelan silana telah memperbaiki sifat mekanik komposit. Ujian koyak menunjukkan peningkatan nilai tork daripada 0 hingga 15% kepekatan silana. Keputusan juga menunjukkan bahawa sifat regangan dan tenaga penyerapan hentaman didapati telah meningkat dengan kepekatan silana di mana kepekatan yang optimum adalah 15%. Bagaimanapun, data kekerasan tidak menunjukkan sebarang perubahan yang ketara dengan peningkatan kepekatan silana. Pemeriksaan morfologi terhadap sampel menggunakan mikroskop imbasan elektron juga menunjukkan bahawa perlekatan antara gentian kaca tikar dan matriks NR/HDPE tela...
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Abstract Electrically conductive adhesive (ECA) is a popular alternative to replace lead solder interconnect material in most areas of electronic packaging. ECA mainly consists of an organic/polymeric binder matrix and metal filler. These... more
Abstract Electrically conductive adhesive (ECA) is a popular alternative to replace lead solder interconnect material in most areas of electronic packaging. ECA mainly consists of an organic/polymeric binder matrix and metal filler. These composite materials provide both ...
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Abstract Five different types of clean flux and no-clean flux, which are mainly used in flip chip die attach, have been analyzed in respect to the wettability of eutectic solder bump in flip chip PBGA. An experimental study is carried out... more
Abstract Five different types of clean flux and no-clean flux, which are mainly used in flip chip die attach, have been analyzed in respect to the wettability of eutectic solder bump in flip chip PBGA. An experimental study is carried out to measure the spreading area of the ...
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... Ahmad*, Zainudin Kornain, Mohd Faizul Md Idros* *National University of Malaysia Faculty of Engineering 43600, Bangi, Selangor, MALAYSIA Email : ibrahim@vlsi.eng ... [9] Shahrul Aman Mohd Saari, Mohd Rofei Mat Hussin, Ahmad Sabirin... more
... Ahmad*, Zainudin Kornain, Mohd Faizul Md Idros* *National University of Malaysia Faculty of Engineering 43600, Bangi, Selangor, MALAYSIA Email : ibrahim@vlsi.eng ... [9] Shahrul Aman Mohd Saari, Mohd Rofei Mat Hussin, Ahmad Sabirin Zoolfakar and Dr. Mohd Rais Ahmad ...
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ABSTRACT New nanocomposites of an unsaturated polyester resin (UPR) and cellulose nanocrystals (CNCs) were prepared. Effects of CNC silane surface treatment on the morphology, mechanical and thermal properties, viscoelastic behavior and... more
ABSTRACT New nanocomposites of an unsaturated polyester resin (UPR) and cellulose nanocrystals (CNCs) were prepared. Effects of CNC silane surface treatment on the morphology, mechanical and thermal properties, viscoelastic behavior and water absorption of CNC reinforced UPR have been studied. The results showed that the crystallinity index of the CNCs reduced after the surface treatment. However, it did not impact the size and aspect ratio of the rod-like nanoparticles. Tensile tests showed that both the strength and stiffness of the UPR improved upon the incorporation of silane treated CNCs (STCNCs), whereas no significant changes were observed on the impact energy after the treatment. Interestingly, the impact energy increased significantly with the addition of untreated CNCs. The viscoelastic behavior and thermal degradation for both the CNC and STCNC-reinforced nanocomposites were improved. The water-absorption behavior of the UPR was found to decrease upon incorporation of CNCs, and a further reduction was observed with STCNCs.
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Nanocellulose was isolated from mengkuang leaves (Pandanus tectorius) by using concentrated sulphuric acid. The structural analysis of the leaves at different stages of treatments was performed by fourier transform infrared spectroscopy... more
Nanocellulose was isolated from mengkuang leaves (Pandanus tectorius) by using concentrated sulphuric acid. The structural analysis of the leaves at different stages of treatments was performed by fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Transmission electron microscope (TEM) was used to investigate the dimensions of the isolated nanocellulose. The FTIR and XRD results indicated that the hemicelluloses and lignin were removed extensively in the extracted cellulose and nanocellulose, and the crystallinity were increased after removing these components. The TEM image showed that the diameter of isolated nanocellulose between 5-25 nm. The isolated nanocellulose may have applications in the fields of nanocomposites.
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The aim of this research is to prepare biodegradable plastics which are made from the natural materials. In this study, solution casting technique is used to prepare the cassava starch nanocomposite reinforced kenaf. Prior to that, kenaf... more
The aim of this research is to prepare biodegradable plastics which are made from the natural materials. In this study, solution casting technique is used to prepare the cassava starch nanocomposite reinforced kenaf. Prior to that, kenaf fibers undergo alkali and bleaching treatments in order to prepare the cellulose. Nanocellulose which used as reinforcing nanoparticle in the composites was then prepared by acid hydrolysis of obtained cellulose with 65% sulphuric acid. The preparation of cassava starch biocomposites was done using the mixture of sorbitol/glycerol (1:1) with various cellulose loading (0%, 2%, 4%, 6%, 8% and 10%). Finer size of cellulose is examined from the transmissions electron microscopy (TEM) analysis with diameter of 12±3.04 nm and length of 70-190 nm recorded. As for field emission scanning electron microscope (FESEM) analysis, good dispersion and strong interaction between starch and cellulose had been observed for the nanocomposite films. These contribute fo...
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Rubber wood sawdust fillers were mixed with unsaturated polyester matrix, which was prepared by recycling of PET waste from soft drink bottles, to prepare rubber wood sawdust/UPR composite. PET wastes were subjected to recycle by... more
Rubber wood sawdust fillers were mixed with unsaturated polyester matrix, which was prepared by recycling of PET waste from soft drink bottles, to prepare rubber wood sawdust/UPR composite. PET wastes were subjected to recycle by glycolysis and depolymerized to its monomer and dimmer. The glycolysed product was used to prepare unsaturated polyester resin. The FTIR analysis has been done on
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The effects of PE-g-MA as a compatibilizer in binary blends of 70/30 high-density polyethylene/epoxidized natural rubber (HDPE/ENR) have been investigated by means of mechanical analysis and scanning electron microscopy. The special... more
The effects of PE-g-MA as a compatibilizer in binary blends of 70/30 high-density polyethylene/epoxidized natural rubber (HDPE/ENR) have been investigated by means of mechanical analysis and scanning electron microscopy. The special emphasis was given ...
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Mechanical behavior of short Twaron fiber thermoplastic natural rubber (TPNR) has been studied with respect to fiber loading and extrusion rates. The composites are prepared at two different compositions of NR/LLDPE matrixes i.e., 60/40... more
Mechanical behavior of short Twaron fiber thermoplastic natural rubber (TPNR) has been studied with respect to fiber loading and extrusion rates. The composites are prepared at two different compositions of NR/LLDPE matrixes i.e., 60/40 and 40/60. Twaron fibers are varied from 0 to 25% in the composites. The temperature profile for extrusion is 140, 145, 150, and 155°C for feeding zone, melting zone, mixing zone, and die respectively with the extrusion rate of 30, 50, 80, and 100 rpm. It has been found that the tensile strength, Young’s modulus, and impact strength increases with fiber loading, but the strain at break decreases. The optimum fiber loading in the system is found to be 20% in both blends. However, there is no effect of extrusion rate on the strength of composite observed.
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ABSTRACT Cellulose was extracted from torch ginger stems through alkali and bleaching treatments. The material obtained after each stage of the treatments was carefully characterised and its chemical composition was determined. Structural... more
ABSTRACT Cellulose was extracted from torch ginger stems through alkali and bleaching treatments. The material obtained after each stage of the treatments was carefully characterised and its chemical composition was determined. Structural analysis was carried out by Fourier transform infrared (FTIR) spectroscopy. The results indicated that the progressive removal of hemicellulose and lignin from the extracted cellulose. The α-cellulose content was increased extensively with successive treatments. The morphology observation with scanning electron microscope (SEM) showed that the average diameter of the extracted cellulose was reduced from 300 µm to 12 µm. X-ray diffraction (XRD) analysis revealed that the crystallinity increased after each treatment with an increased of the fibre crystallinity from 45% to 67%. The thermal stability of the fibre was found to increase at various purification stages when compared to the raw material.
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ABSTRACT Unsaturated polyester resin synthesized from glycolyzed product of polyethylene terephthalate (PET) waste was used as a matrix to form coconut fiber/polyester composites. PET wastes were recycled through glycolysis and... more
ABSTRACT Unsaturated polyester resin synthesized from glycolyzed product of polyethylene terephthalate (PET) waste was used as a matrix to form coconut fiber/polyester composites. PET wastes were recycled through glycolysis and polyesterification reaction to produce a formulation for unsaturated polyester resin (UPR). FTIR spectra of glycolyzed product and prepared resin revealed that cross-links between unsaturated polyester chain and styrene monomer occurred at the saturated sites which resulted in the forming of cross linking network. To improve the adhesion between coconut fiber and polyester resin, various concentrations of alkali, silane and silane on alkalized fiber were applied and the optimum concentration of treatments was determined. The influence of water uptake on the sorption characteristics of composites was studied via immersion in distilled water at room temperature. Surface treatment of coconut fiber caused a significant increase in the tensile properties with the optimum treatment is 0.5 % silane on the 5 % alkalized coconut fiber/polyester composites. It was also observed that the treated fiber composites showed lower water absorption properties in comparison to those of untreated fiber composites. This observation was well supported by the SEM investigations of the fracture surfaces. From the study, it was concluded that polyester reinforced coconut fiber composites derived from recycling polyethylene terephthalate (PET) waste may have the potential application in the fields of construction and automotive interior substrates.
Nata de coco, a dessert originally from the Philippines is produced by fermentation of coconut water with a culture of Acetobacter xylinum, a gram negative bacterium. Acetobacter xylinum metabolizes glucose in coconut juice and converts... more
Nata de coco, a dessert originally from the Philippines is produced by fermentation of coconut water with a culture of Acetobacter xylinum, a gram negative bacterium. Acetobacter xylinum metabolizes glucose in coconut juice and converts it into ...
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ABSTRACT The use of rice husk (RH) powder as a reinforcing filler in blends of natural rubber and high-density polyethylene (NR/HDPE) was studied via surface modification of the particle surface. The RH powder was pre-washed with sodium... more
ABSTRACT The use of rice husk (RH) powder as a reinforcing filler in blends of natural rubber and high-density polyethylene (NR/HDPE) was studied via surface modification of the particle surface. The RH powder was pre-washed with sodium hydroxide (NaOH) prior to coating with liquid natural rubber (LNR) and reinforced by electron beam (EB) irradiation. The effects of the radiation dosage on the LNR-coated rice husk (RHr) as a reinforcing agent in the composite were evaluated from the mechanical and thermal properties, as well as from the blend homogeneity. The mechanical properties enhanced with the dosage of radiation on the RHr, and reached an optimum dose in the range 20–30 kGy. The composites filled with radiated RHr showed the highest storage modulus (E′) and low tangent delta (tan δ) a radiation dosage of 30 kGy. The scanning electron microscopy (SEM) micrograph of the fractural tensile surface showed that an effective RHr particle matrix interaction occurred in the RH powder at a radiation dosage of 20 kGy. Improved RH filler–matrix interfacial bond strength and adhesion to the matrix were achieved by coating the RH powder and curing the rubber coat by electron beam irradiation.
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This study highlights the potential of cellulose nanocrystals (CNCs) from kenaf fibers as reinforcing fillers in starch-based biocomposites. By hydrolyzing kenaf fibers with 65 wt.% sulfuric acid, CNCs with diameters of 12±3.4 nm were... more
This study highlights the potential of cellulose nanocrystals (CNCs) from kenaf fibers as reinforcing fillers in starch-based biocomposites. By hydrolyzing kenaf fibers with 65 wt.% sulfuric acid, CNCs with diameters of 12±3.4 nm were obtained. Cassava starch biocomposites were prepared using a solution casting method which includes 0–10 wt.% kenaf CNCs as fillers and glycerol/sorbitol (ratio of 50: 50) as plasticizer. The composites were characterized by different techniques, including tensile tests, thermal stability tests, ...
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Unsaturated polyester resin, synthesized from glycolyzed product of poly (ethylene terephthalate)(PET) waste was combined with rice husks to form rice husk (RH)/polyester composites. PET from post-consumer soft drink bottles was recycled... more
Unsaturated polyester resin, synthesized from glycolyzed product of poly (ethylene terephthalate)(PET) waste was combined with rice husks to form rice husk (RH)/polyester composites. PET from post-consumer soft drink bottles was recycled through glycolysis, ...