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PublicationEffect of nanosepiolite and nanosilica content, polyethylene-grafted-maleic anhydride and irganox 1010 on tensile and morphological of low density polyethylene nanocomposites(Universiti Malaysia Perlis (UniMAP), 2017)Nanocomposites of thermoplastic blend of low density polyethylene (LDPE) filled with nanosepiolite and nanosilica was investigated. All of the test samples were prepared using Brabender Internal Mixer Plastograph EC Plus (Duisberg, Germany) at 160°C, speed of 50 rpm and moulded using compression at temperature of I60°C. Results showed that the nanosepiolite filled composites gave better tensile properties than nanosilica filled composites at same filler loading. The adhesion between filler and matrix was improved by using MAPE as a compatibilizer at 3 phr content. All the properties were improved for both nanocomposites. The addition of antioxidant into the nanocomposites showed that the lowest content of antioxidant at 1 phr gave higher tensile strength and Young's modulus compared to 3 phr and 5 phr. The effect of thermal ageing was also investigated by exposing the nanocomposites in air circulated oven at 70°C for 72 hours. The nanocomposites were found to show better properties than the control nanocomposites when antioxidant were added to the nanocomposite system and supported by S ~ M morphology and FTIR analysis.
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PublicationCharacterization and properties of low linear density polyethylene / Typha Latifolia (LLDPE / Typha Latifolia) composites(Universiti Malaysia Perlis (UniMAP), 2016)Fabricating polymer (low linear density polyethylene) with a natural fiber such as Typha Latifo/ia, will provide a new opportunities to the manufacture a green plastic products. In this study, three objectives have been carried out such as characterization of the Typha Latifolia, effect of different sizes and loading and influences of NaOH modification on fiber towards LLDPE/Typha Latifolia composite. The experimental was prepared by using extruder machine with parameter of 150°C- 160°C temperature and speed of 70rpm. The characterization such as tensile properties (tensile strength, elongation at break and Young modulus), X-ray fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) on composites were determined. Results indicated that the distribution of the Fine size Typha Latifolia was very prominent between 99.19 J.!In and 447.37J.!m on particle size analyzer while the coarse in between 1-4 mm. XRF results detected the calcium oxalate monohydrate and potassium, which is accumulated between ultimate Typha Latifolia fibers. The incorporation of Typha Latifolia into LLDPE found that the reduction on tensile strength and elongation at break except for Young's modulus. However, the fine size of Typha Latifolia shows the high value on properties compared with Coarse size at all loading ratios of LLDPE/Typha Latifo/ia composites. The addition of 15% fine size Typha Latifolia with 3% concentration of NaOH treatment demonstrated the optimum value in tensile strength and elongation at break of LLDPE/Typha Latifolia composites excluding young modulus. It was believed that the hydroxide sodium NaOH on fiber thus improved the tensile properties of the composites. The observation on the morphology of the composites proved that the treatment improved the adhesion between fibers and matrix.
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PublicationPembangunan teknik keupayaan cas sifar untuk aplikasi perlindungan kakisan(Universiti Malaysia Perlis (UniMAP), 2016)This study aims to modify the practice of using over-voltage concept of polarization process in cathodic protection to the potential of zero charges (Epzc) as a new technique of corrosion prevention. At Epzc, a metal surface is not in contact with an aqueous solution due to the absence of electrical charge and no electrostatic attraction. A chemical adsorption caused by oxidation reaction does not occur at Epzc· The removal of electrical charges at the electrode-electrolyte interface leads the desorption of ionic charges which causes the metal surface suffers no longer a corrosion reaction due to the absence of a charge transfers. The determination of Epzc is carried out by measuring the border line of adsorption and desorption of charged ions on the metal surface by the intersected inducing polarization methods on the intermediate rod. The experimental Epzc value ( -703 m V vs SCE) is more negative than the corrosion potential (Ecorr = -701 mV vs SCE) shows the immersed metal in 3.5% NaCl solution have an excessive positive charge. Therefore, the negative charge is required to eliminate or neutralize the positive charges to bring the metal surface to Epzc· The charge removal is a discharging of double-layer process on the metal-solution interface. It is carried out by supplying electrons to the extent necessary just to eliminate the positive charges on the metal surface by using potentiostat. The discharging was perfmmed by means of voltage scan method around Epzc (Epzc scan) with an ideal magnitude at about 2 m V, which is slightly negative than corrosion potential (Ecorr) at the lowest rate (1.0 x 10-2 mV/ min). The plot of current density versus time takes about 100 hours to displays a capacitor discharging curve profile. The current requirement for corrosion protection at Epzc is not critical after a 100 hour period. The planned interval immersion tests on reactive Mg metals clearly prove that corrosion protection at Epzc is succeed and their corrosion protection efficiency is between 93-96% in 3.5 % NaCl solution.
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PublicationPreparation and characterization of epoxy/poly (Methyl Methacrylate) (PMMA) blend system with carbon based conductive fillers(Universiti Malaysia Perlis (UniMAP), 2016)Prioritization in investigating the potential of carbon based conductive filler, on carbon black (CB) and graphene nanoplatelet (GNP), to modify the mechanical, electrical and thermal properties of the polymer matrix was achieved via uniform dispersion and identifying the set of mechanical failure mechanism, which leads to relevant modification methods. The principle idea of this research study was to understand the function of immiscible polymer blend system towards the reduction of percolation threshold on conductive filler, via selective localization mechanism. This study thematically divided into five parts. In the first part, the electrical properties of CB in single matrix epoxy system was investigated and the percolation threshold was determined at 15 vol.% loading. In the second part, the dual matrixes system, which consists of epoxy and poly (methyl methacrylate) (PMMA) prepared via two different processing methods: solvent dissolution (SD) and direct mixing (DM) were investigated. This part involved different processing methods in preparing the polymer blend system, which has led to selective localization of filler in the blend system. A variety of experimental methods was described which were employed to investigate the structure and properties of the composites. Using the predetermined CB percolation in single matrix system, the optimum PMMA content for both SD and DM methods are 40 and 10 vol.%, respectively. After that, the percolation threshold of CB for both dual matrixes system were investigated and determined at 10 and 5 vol.% for both SD and DM methods. Both methods successfully reduced the optimum CB loading in single matrix system, with composites prepared from DM method outperformed SD method, in terms of mechanical and electrical properties, where increment of almost 19% on flexural strength and three order of magnitude on electrical bulk conductivity was observed on DM method as compared to single matrix system. Next, the GNP percolated loading was determined in single matrix epoxy system, where 1 vol.% of GNP was used in dual matrixes epoxy/PMMA system using DM method. Similar findings were observed, where the electrical conductivity of GNP filled epoxy/PMMA system increased two order of magnitude, with 30 vol.% PMMA content and the optimum loading of GNP reduced from 1 to 0.4 vol.%. Nevertheless, extensive studies were done on the interaction between fillers, PMMA, and epoxy, through mechanical and thermal properties. The final part of the thesis deals with surface modification on both CB and GNP, which consist of three different modification methods: wet oxidation, impregnation, and heat treatment. The appreciable improvement was measured in the mechanical properties, which electron microscopy was carried out to investigate the microstructure and interfacial interaction between the filler and matrix. The present work demonstrated the significant ability of immiscible polymer blends system to reduce the percolation threshold of both carbon based conductive fillers while surface modification on both CB and GNP show better dispersion and interfacial interaction. This open a broad horizon for a variety of application, especially conductive adhesives.
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PublicationCharacterization, mechanical and thermal properties of polyaniline (PANI)-epoxy composite using different types of natural fibers(Universiti Malaysia Perlis (UniMAP), 2016)In this study, three types of natural fiber that are bagasse, rice husk and coir were incorporated into PANI/Epoxy matrix. All natural fiber was set to the same percentage that is 5wt%. PANI/Epoxy was mixed in a container and stirred well until it become homogenously. Then, all the natural fiber was added into the PANI/Epoxy and stirred it until homogenously before put into the mould to let the composite cure for one day. The effects of thermal (Thermogravimetric Analysis, TGA, Dynamic Scanning Calorimetry, DSC), mechanical (tensile strength, modulus of elasticity, elongation at break) and morphological (Scanning Electron Microscope, SEM) were investigated. From the results, it was found that the tensile strength ofthe composite found to be decreased with addition of natural fiber. Between three types of natural fiber, bagasse fiber has the highest value of tensile strength. For elongation at break, it has been said that the elongation at break was decreased with the addition of the natural fiber. For the modulus of elasticity, there are increases in modulus of elasticity with addition of natural fiber. There are two stage weight loss behaviors that are almost at the same at 200°C and 350°C for all three types of natural fiber. Addition of natural fiber has reduced the percentage of weight loss. This indicates that addition of natural fiber into PANI/Epoxy has improved the thermal stability. The glass transition temperature (T g) was increased with the addition of natural fiber.