EFFECT OF CHEMICAL TREATMENT ON RICE HUSK (RH) REINFORCED POLYETHYLENE (PE) COMPOSITES

In this study rice husk reinforced polyethylene composites and their test specimens were manufactured using a single screw extruder and an injection molding machine, respectively. Raw rice husk was chemically treated with benzene diazonium salt in alkali, acidic, and neutral media, in order to improve in the mechanical properties. The mechanical properties of the composites prepared from alkaline media treated rice husk were found to increase substantially compared to those of acidic media, neutral media, and untreated ones. However, the values for the alkaline media treated rice husk-PE composites at all mixing ratios were found to be higher than those of treated acidic media, treated neutral media, and untreated rice husk composites respectively. The SEM micrographs reveal that interfacial bonding between the treated filler and the matrix has significantly improved, suggesting that better dispersion of the filler into the matrix was achieved upon treatment of rice husk. Based on filler loading, 35% filler reinforced composites had the optimum set of mechanical properties among all composites manufactured

A Cross-Shore Beach Profile Evolution Model

Developing an accurate and reliable time-averaged beach profile evolution model under normal and storm conditions is a challenging task. Over the last few decades, a number of beach deformation models have been developed under limited experimental conditions and uncertainties, and sometimes they required a long computation time. It is quite evident that a large amount of wave, current, sediment and beach profile data is available today. The present study leads to the development of a simple two-dimensional beach profile evolution model with on-offshore sand bar formation under non-storm and storm conditions based on the time-averaged suspended sediment concentration models of Jayaratne & Shibayama [2007] and Jayaratne et al. [2011]. These models were formulated for computing sediment concentration in and outside the surf zone under three different mechanisms: 1) suspension due to turbulent motion over sand ripples, 2) suspension from sheet flow layer and, 3) suspension due to turbulent motion under breaking waves. The suspended load is calculated by the product of time-averaged sediment concentration and undertow velocity from edge of the wave boundary layer to wave trough, and mass transport velocity from wave trough to crest (bore-like wave region). Sediment transport in wave boundary layer is computed from the modified Watanabe [1982] model. Rattanapitikon and Shibayama [1998] wave model is used to calculate the average rate of energy dissipation due to wave breaking. The beach deformation is calculated from the conservation of sediment mass while the avalanching concept of Larson and Kraus [1989] is used to re-distribute the sediment mass in neighbouring grids for a steady solution. Published field-scale experimental and natural beach profiles from 5 high-quality data sources from 1983-2009 [Kajima et al., 1983; Kraus and Larson, 1988; Port and Airport Research Institute, Japan, 2005, 2009; Hasan & Takewaka, 2007, 2009; Ruessink et al., 2007] are used to verify the performance of the proposed numerical model. The key feature in this process-based model is that it takes about a couple of minutes to simulate beach profiles of a 2-3 days storm qualitatively at a fairly satisfactory level using a standard personal computer. It is found that the present numerical predictions are not better than the null hypothesis as the model is in a stage of ongoing development. Therefore, it is believed that the final model is often more value to a practical coastal engineer than a very detailed study of hydrodynamics and sediment transport study, however an incorporation of swash dynamics, more precise evaluation of offshore sand bar formation and continuation to a longer time scale with precise beach deformation is recommended as the next stage of the model

Thermomechanical Properties of Jute/Bamboo Cellulose Composite and Its Hybrid Composites: The Effects of Treatment and Fiber Loading

Jute cellulose composite (JCC), bamboo cellulose composite (BCC), untreated hybrid jute-bamboo fiber composite (UJBC), and jute-bamboo cellulose hybrid biocomposite (JBCC) were fabricated. All cellulose hybrid composites were fabricated with chemical treated jute-bamboo cellulose fiber at 1 : 1 weight ratio and low-density polyethylene (LDPE). The effect of chemical treatment and fiber loading on the thermal, mechanical, and morphological properties of composites was investigated. Treated jute and bamboo cellulose were characterized by Fourier transform infrared spectroscopy (FTIR) to confirm the effectiveness of treatment. All composites were characterized by tensile testing, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Additionally, surface morphology and water absorption test was reported. The FTIR results revealed that jute and bamboo cellulose prepared are identical to commercial cellulose. The tensile strength and Young’s modulus of composites are optimum at 10 weight percentage (wt%) fibers loading. All cellulose composites showed high onset decomposition temperature. At 10 wt% fiber loading, JBCC shows highest activation energy followed by BCC and JCC. Significant reduction in crystallinity index was shown by BCC which reduced by 14%. JBCC shows the lowest water absorption up to 43 times lower compared to UJBC. The significant improved mechanical and morphological properties of treated cellulose hybrid composites are further supported by SEM images

Maleic anhydride modified unsaturated polyester composites reinforced with chicken feather fiber: dielectric and morphological study

In this study, chicken feather fiber has been used as reinforcement and unsaturated polyester as matrix. In addition, unsaturated polyester had been modified using maleic anhydride and reinforced with chicken feather fiber. The dielectric properties of the unsaturated polyester reinforced chicken feather fiber have been studied with reference to maleic anhydride modification and various fiber loading. The structures of unsaturated polyester and maleic anhydride modified unsaturated polyester have been investigated. SEM indicated an improved interfacial bonding between polymer and fiber through maleic anhydride modification. XRD analysis indicated the development of intercalated maleic ahydride structure, which in turn forms intercalated unsaturated polyester composite. It is observed that maleic anhydride modified composites increases dielectric constant, dissipation factor and resistivity. The dielectric constant, dissipation factor and resistivity increases with fiber content for the entire range of frequencies. The values are high for the composites with 40wt% fiber content. The results also indicated that both composite systems are stable at low frequency, i.e. at 60Hz and high frequency, i.e. at 1000 KHz. The increments of dielectric values are high at low frequency region and gradually becoming low at higher frequencies

Electrophoretic Deposition (EPD) of Multi-Walled Carbon Nanotubes (Mwcnts) Onto Carbon Fiber (CF) Fabric

The Fiber Reinforced Polymer Composite (FRPC) has been widely employed in structural applications. However, adding nanoparticles such as multi-walled carbon nanotubes (MWCNTs) can be used to improve the composites' mechanical properties substantially. The purpose of this study is to investigate the stability of MWCNTs in distilled water (DW) and dimethylformamide (DMF). Electrophoretic deposition (EPD) was chosen as the method for depositing MWCNTs onto carbon fiber (CF) fabric because of the advantages of simple equipment and inexpensive cost. Thus, the effect of voltage and deposition time were examined to attain the ideal condition for the EPD of MWCNTs onto CF fabric. The stability of dispersed MWCNTs in various dispersing mediums was explored as the importance of the MWCNTs to remain stable in the medium is essential to achieve homogeneous deposition. The UV-Vis and colloidal stability test revealed that MWCNTs dispersed in DMF have greater stability than DW. Scanning Electrode Microscopy (SEM) images exhibited that 10 minutes and a 20 V voltage were the optimal conditions for the deposition of MWCNTs onto CF fabric

Biodiesel production from Macro Algae as a green fuel for diesel engine

Transesterification is an effective method to produce significant levels of biodiesel from renewable resources like plant oils and animal fats. Macroalgae is one of the inexpensive sources of oil feedstock for biodiesel production which is abundantly available in the sea areas. In this study algae oil was extracted from several types of macroalgae species namely L. Epiphytic, Cladophora, Agardhiella, Gracilaria, Spirogyra and Bryopsis Pennata. And their oils were then converted into biodiesel by the transesterification process. The extraction of algae oil from macroalgae was accomplished through Soxhlet method. The fuel properties of biodiesel was characterized through FTIR analysis and found to be similar chemical composition as to petroleum diesel. In addition, the highest yield was found (92%) at methanol to oil ratio 4:1, catalyst 1.0 wt% (KOH) in heating with stirring

Physical, Mechanical, and Thermal Analysis of Polylactic Acid/Fumed Silica/Clay (1.28E) Nanocomposites

Polylactic acid/fumed silica/clay (PLA/FS/clay) (1.28E) nanocomposites have been successfully prepared by solution-intercalation film-casting technique. The resultant nanocomposites were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), tensile test, thermogravimetric analysis (TGA), and moisture absorption test. The FT-IR spectrum indicated that PLA/FS/clay with 2 wt% hadmuch broader peak compared to 5 wt%, 10 wt%, and 15wt% nanocomposites. Incorporation of clay (1.28E) with 2wt% showed the best compatibility with PLA/FS matrix. PLA/FS/clay (1.28E) nanocomposite with 2wt% of clay loading had higher tensile strength and modulus compared to other nanocomposites. The thermal stability and activation energy of 2wt% of PLA/FS/clay (1.28E) nanocomposite are the highest among all the nanocomposites. The moisture absorbed into PLA/FS/clay (1.28E) nanocomposite was significantly reduced with clay loading of 2 wt%

Polyvinyl Alcohol/Silica/Clay Composites: Effect Of Clay On Surface Morphology And Thermo-Mechanical Properties

A simplified route towards the synthesis of polyvinyl alcohol/silica/clay (PVA-SiO2-clay) composites was presented. PVA-SiO2-clay composites were prepared via solution intercalation method. All the composites were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), adsorption isotherm (BET), X-ray fluorescence (XRF), tensile test and Thermogravimetric Analysis (TGA). FTIR spectrum indicated that PVA-SiO2-clay composites especially clay (1.28E) loaded composites had much less transmittance percentage compared to pure PVA and others clay composites. The SEM revealed that the interfacial bonding between PVA-SiO2 and clay (1.28E) was much better than others clay loaded composites which was reflected in adsorption isotherm. The BET result also showed high specific surface area with low diameter of pore size of the composites. The thermal stability of PVA-SiO2-clay (1.28E) composites was the highest and it had higher activation energy due to the strong bonding between the trimethyl stearyl ammonium with both PVA-SiO2. The XRF result showed that clay (1.28E) loaded composites contained significant high percentage of Si which confirmed the presence of Si-O-Si stretching vibration while the high percentage of K proved the clay mineral content in the composite. Clay (1.28E) enhanced the tensile strength and modulus of PVA-SiO2-clay composites among all the composites

Physical, mechanical, morphological and thermal analysis of styrene-co-glycidyl methacrylate / fumed silica / clay nanocomposites

Styrene-co-glycidyl methacrylate-fumed silica-clay (ST-co-GMA-fsi-clay) nanocomposites have been prepared via free radical polymerization in the presence of benzoyl peroxide. The nanocomposites are characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), adsorption isotherm, tensile test, thermogravimetric analysis (TGA) and moisture absorption. FT-IR shows the Si-O-C peak that represented ST-co-GMA-fsi bonding while Si-O-Si peak shows the bonding of fsi-clay. The surface morphology shows the well dispersion of clay (1.30E) into ST-co-GMA-fsi nanocomposite. 2wt% of ST-co-GMA-fsi-clay (1.30E) nanocomposite has higher specific surface area and average pore volume with less pore size. Incorporation of 2wt% of clay (1.30E) improves the tensile strength and modulus of the nanocomposites as well as higher thermal stability and activation energy. 2wt% of ST-co-GMA-fsi-clay (1.30E) nanocomposite shows the lowest moisture absorption value. © 2017 Penerbit UTM Press. All rights reserved