28 research outputs found

    Physico-chemical and thermal properties of starch derived from sugar palm tree (arenga pinnata)

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    Petroleum based polymers are extremely stable and commonly used in various industries include food packaging, furniture and automotive. However, the waste that come from petroleum based polymer material has brought negative impact not only for human being, but also create the serious environmental problems. Hence, biopolymers that come from natural source such as starches are now being considered as an alternative to the existing petrochemical based polymers. This study was aimed to examine the potential of sugar palm starch extracted from sugar palm tree (Arenga pinnata) as a new biopolymer. The important properties of sugar palm starch studied were the chemical properties, thermal properties, particle size and morphological surface. The starches isolated from sugar palm tree contained comparable amounts of amylose (37.60 %) which were higher than tapioca, sago, potato, wheat and maize. The results showed significant differences in the chemical content as well as in the granule sizes of sugar palm starch. Thermal characteristic studies using thermogravimetry analysis and differential scanning calorimetry showed that sugar palm starch was thermally stable than other starches. Study on morphological surface indicated that sugar palm starch were rounded and oval-shaped

    Thermoplastic Matrix Material Selection using Multi Criteria Decision Making Method for Hybrid Polymer Composites

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    Multi criteria decision making (MDCM) methods are amongst the approaches available in aiding composite designers to make the final decision especially during the material selection process where multiple solutions are present and various requirements are required to be satisfied simultaneously. Thus, in this paper, material selection process of thermoplastic matrix using MDCM methods for hybrid natural fiber/glass fiber polymer composites is presented. The aim is to identify the most suitable type of thermoplastic matrix to be used in the hybrid polymer composites formulation. The Weighted Sum Method (WSM) is applied in the selection process of seven candidate thermoplastic matrix materials based on the product design specifications. The overall analysis highlights that low density polyethylene (LDPE) is the preferred matrix for the intended application based on the highest scores obtained compared to other candidate materials. A signal-to-noise (S/N) ratio analysis was further performed to validate the initial selection results where LDPE once again outperformed other candidate materials with highest S/N ratio score in the noncompensatory approach

    Effect of corn husk fibre loading on thermal and biodegradable properties of kenaf/cornhusk fibre reinforced corn starch-based hybrid composites

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    This paper documents the thermal and biodegradation behaviour of kenaf/cornhusk fiber reinforced corn starch-based hybrid composites film (CS/K–CH) produced by solution casting method. To develop both components as biodegradable hybrid composite, this research used corn starch as matrix, kenaf fiber and cornhusk fibre as a filler. Changes in physical structure and weight from the soil burial test were measured using Mettler Toledo digital balance ME. Films produced from physically blended corn starch reinforced kenaf biocomposites films (CS/K) biocomposite film had faster biodegradation and lost 96.18% of weight within 10 days compared with corn starch hybrid composites that only lost 83.82% of total weight. It was observed that the control film, CS/K biocomposite film was completely degraded after 10 days, meanwhile it took 12 days for hybrid composite films to be fully degrade. The thermal properties such as TGA and DTG were also measured. Addition of corn husk fiber significantly improve the film's thermal properties. Glass transition temperatures of corn starch hybrid films were significantly lowered when cornhusk compositions were increased from 0.2% wt to 0.8% wt. Importantly, the current work has demonstrated that hybrid films made of corn starch can be a suitable biodegradable material for substitute synthetic plastic

    Sugar Palm (Arenga Pinnata (Wurmb.) Merr) Cellulosic Fibre Hierarchy: A Comprehensive Approach From Macro To Nano Scale

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    Sugar palm (Arenga pinnata) fibre is considered as a waste product of the agricultural industry. This paper is investigating the isolation of nanofibrillated cellulose from sugar palm fibres produced by a chemo-mechanical approach, thus opening a new way to utilize waste products more efficiently. Chemical pre-treatments, namely delignification and mercerization processes, were initially involved to extract the sugar palm cellulose. Then, mechanical pre-treatment was performed by passing the sugar palm cellulose through a refiner to avoid clogging in the subsequent process of high pressurized homogenization. Nanofibrillated cellulose was then characterized by its chemical properties (Fourier transform infrared spectroscopy), physical morphological properties (i.e. scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis), and thermogravimetric analysis.The nanofibres were attained at 500 bar for 15 cycles with 92% yield. The results showed that the average diameter and length of the nanofibrillated cellulose were found to be 5.5 ± 1.0nm and several micrometres, respectively. They also displayed higher crystallinity (81.2%) and thermal stability compared to raw fibres, which served its purpose as an effective reinforcing material for use as bio-nanocomposites. The nanocellulose developed promises to be a very versatile material by having a huge potential in many applications, encompassing bio-packaging to scaffolds for tissue regeneratio

    Mechanical properties of natural fibre reinforced PVC composites: A review

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    Poly (vinyl chloride), which is commonly abbreviated as PVC, is widely used due to it being inexpensive, durable, and flexible. As a hard thermoplastic, PVC is used in the applications such as in building materials pipe and plumbing. The factors that should be considered in using PVC is safety and environmental issues. Mixing PVC with natural fibres is an interesting alternative. The main challenge in the research on natural fibre/polymer composites is the poor compatibility between the fibres and the matrix because this will affect their bonding strength. During the mixing with PVC, some natural fibres may acts as reinforcing materials while other natural fibres only act as filler, which contribute less to mechanical strength improvement. However, generally natural fibres also give positive outcome to the stiffness of the composites while decreasing the density

    Low intensity ultrasound induced apoptosis in MCF-7 breast cancer cell lines

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    According to the World Cancer Research Fund International (WCRFI), breast cancer is the most common type of cancer in women worldwide with recorded 1.7 million new cases in 2012. The main line of treatments is still limited to chemotherapy, surgery and radiotherapy which could lead to a wide range of dangerous side effects. This study was conducted to evaluate the effect of low intensity ultrasound (LIUS) on cell proliferation, percentage of living and dead cells and the induction of apoptosis on the MCF-7 cell line with CHO cells as the control for non-cancerous group. In order to achieve the objective of this study, several methods of cell-bioguided assays were used including the MTT assay for cell proliferation, Live/Dead assay for the determination of both live and dead cells and gene expression study for the detection of apoptosis in the cells. The cytotoxicity and Live/Dead assays data provided preliminary data that the LIUS has potential to induce apoptosis in a wide population of breast cancer cells. Furthermore, the LIUS treatment induced the expression of p53-mRNA at a detectable level via qPCR analysis, indicating the activation of apoptosis. In short, our study suggested LIUS dosage used in this study could potentially show positive effects in the induction of apoptosis selectively on the MCF-7 with less harm to the control CHO cells

    Physical, thermal, morphological, and tensile properties of cornstarch-based films as affected by different plasticizers

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    The current research was designed to determine the effect of various concentrations (0%, 25%, 40%, and 55%) of fructose, sorbitol and urea plasticizers in cornstarch-based films, with the aim of achieving a new polymer for the application of biodegradable materials. Casting technique was used to prepare the films. The physical, morphological, thermal, and mechanical properties of produced films were evaluated. The results showed that the thickness, moisture content, and water solubility increased with the addition of plasticizer concentration. While the glass transition temperatures showed an insignificant effect with high plasticizer content. Regardless of plasticizer sort, the tensile stress and Young’s modulus of plasticized films decreased as the plasticizer concentrations were raised beyond 25%. Likewise, the relative crystallinity decreased by increasing the plasticizer content from 0% to 25%, but it began to grow once the concentration increased above 25%. The fructose-plasticized films presented consistent and more coherent surfaces compared to sorbitol and urea counterparts, which appeared less homogeneous surfaces with microcracks. In summary, the plasticizers types and concentrations are affected significantly on the properties and performance of the cornstarch-based film. Film plasticized with 25% fructose appeared the finest set of features and achieved the highest mechanical performance among the plasticizers used in this study

    Mechanical and moisture diffusion behaviour of hybrid Kevlar/Cocos nucifera sheath reinforced epoxy composites

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    The aim of this research is partial replacement of plain woven Kevlar 29(K) with naturally woven cocous nucifera sheath (CS) waste. Laminated K/CS reinforced epoxy hybrid composites were fabricated by hand lay-up method followed by hot compression moulding with 105 °C temperature at 275 bar pressure for 1 h. The total fibre loading of the hybrid composite was maintained 45 wt.% and the ratio of Kevlar and Cocous nucifera sheath varies in weight fraction of 100/0, 75/25, 50/50, 25/75, and 0/100. Mechanical (tensile, flexural, impact), moisture diffusion and morphological behaviour of the laminated composites were evaluated. The results showed that the hybrid composites (75/25) declined the tensile strength by 19% compared to Kevlar fabric reinforced epoxy composites. But, the hybrid composites (75/25) exhibited highest flexural strength (175 MPa) and flexural modulus (18 GPa) than pure Kevlar reinforced epoxy composites. Moreover, the impact toughness of hybrid composites (86 kJ/m2) at 75/25 wt.% showed good agreement with the pure Kevlar fabric reinforced polymer composites (90 kJ/m2). From the moisture diffusion analysis, hybrid composites (75/25) exhibited better moisture resistance. Statistical analysis of the results has been carried out using one way-ANOVA (analysis of variance) and it shows that there is a statically significant difference between the obtained mechanical properties of the laminated composites. Morphology of the tensile fractured laminates showed the delamination's, matrix cracking and fibre/matrix adhesion. From the results, it has been concluded that naturally woven Cocos nucifera sheath has the potential to replace Kevlar fabric in the polymer composites exclusively for defence applications. Keywords: Hybrid composites, Laminated composites, Kevlar fibre, Cocos nucifera sheath, ANOV
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