26 research outputs found
Effect of fibre surface treatment on kenaf filled recycled polypropylene composite
Get PDFLignocelluloses based natural fibre is being used as an alternative to traditional glass and carbon fibre in the composite materials due to its low density and higher specific properties.Furthermore,these fibres are available at a very low cost.Current work is focused on kenaf fibre based reinforced recycled polypropylene composites.In this project,initially the raw kenaf fibre was grinded to a small size (2 to 5 mm) and then mixed with recycled polypropylene (RPP) followed by extrusion through a twinscrew extruder.Fibre loading in the composite was 10, 20, 30 40 and 50% by weight.After that test specimens for tensile, flexural and impact testing were prepared through an injection moulding machine.Melt flow indexer was used to evaluate theflow property of the extruded materials.To improve the interfacial property between fibreand matrix maleic anhydride grafted polypropylene (MAPP)was used as a coupling agent with ratio of 10:1.Mechanical tests showed that significant improvement achieved due to coupling agent.Fibre surface modifications for better adhesion between fibre and matrix were carried out by three ways including alkali,ultrasound and laccase enzyme treatment.Treated fibre was then blended with recycled polypropylene with 40%fibre loading in the presence of MAPP,as 40% loading found the optimum regarding tensile performances with untreated fibre based composites. For alkali treatment,both concentration of the solution and soaking time were considered as treatmentvariables for the fibre.Mechanical tests were carried out to evaluate the optimum treatment condition for the best strength.For ultrasound,normal water was used as media for the treatment.Both temperature and sonication power was considered as treatment variables.Mechanical tests were carried out to evaluate the best strength at optimum condition of fibre treatment.Enzymatic treatment was carried out for an alternative way of fibre treatment.The composites strength was increased by 18% for fibre loading whereas coupling agent improves it by 37%. Ultrasound and alkali treatment of fibre improved the tensile strength of the composites almost by 57%. Weathering and water uptake were carried out for the composites. After that mechanical tests were performed to evaluate the properties of the composites.Thermal test like thermogravimetric analysis (TGA) was carried out to evaluate the thermal stability of the composites.It was found that,RPP degrade at one stage while composites degrade at two stages.Activation energies of the composites were calculated from the TGA analysis.Crystallinity and melting point were detected through differential scanning calorimetry(DSC) analysis. Incorporation of fibre increased the crystallinity of the polymer matrix.Structural morphology was carried out of the fractured samples to evaluate the bonding interface between fibre and matrix.Improved adhesion between fibre and matrix was found for the case of treated fibre based composites in the presence of MAPP.Fourier transform of infrared radiation (FTIR)spectroscopy was used to find out any structural change due to the treatment of the fibre and analysis found that treatment of fibre able to remove the non-cellulosic compound to a varying extent depending on treatment parameters.Response surface method (RSM) was used to optimize process parameters and one of the best set of treatment conditions was 99.96% sonication power at 94.46oC to achieve 28.86 MPa of TS
Preparation and characterization of palm oil based polyalkyd films and composites with multi-walled carbon nanotubes
Get PDFIn this research, polyalkyd resins were prepared from palm oil by using polycondensation reaction. A two-step method viz., alcoholysis and esterification was conducted to synthesize polyalkyd resins. Prior to alcoholysis, crude palm oil was subjected for dehydration process to increase its unsaturation. Different types of catalysts such as, sulphuric acid, para-toluene sulfonic acid, phosphoric acid, sodium hydrogen sulphate and potassium hydrogen sulphate were used for the dehydration. In alcoholysis process, the triglyceride-based dehydrated oil was reacted with glycerol to produce monoglyceride. The prepared monoglyceride was further brought into contact with acid anhydride to prepare polyalkyds. Response surface methodology was used to optimize the reaction parameters for esterification like reaction temperature, reaction time, catalyst concentration, acid anhydride to mono-glyceride ratio and agitation speed. The optimum condition was used to prepare various types of polyalkyds by using different types of acid anhydrides such as, maleic anhydride, succinic anhydride, phthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride and cis-1,2-cyclohexanedicarboxylic anhydride. A comparison was drawn among the resins prepared by using different types and percentages of acid anhydrides. The produced bioresins were characterized for physico-chemical properties such as, viscosity, density, iodine value, acid value, drying time, non-volatile materials content, specific gravity, colour, etc. The resins prepared with optimum reaction parameters were subjected for curing process by using methyl ethyl ketone peroxide and cobalt naphthanate. To enhance the resinous property, multi-walled carbon nanotubes (MWCNTs) were dispersed into the resin at different percentages of loading such as, 0.5, 1.0 and 1.5 wt.%. The loading was optimized based on the tensile strength of the film. Finally, in-situ polymerization with carbon nanotubes during esterification was performed by adding optimum percentage of loading. The films produced from different formulations were characterized by different testing such as, adhesion, chemical resistivity, thermogravimetric analysis, differential scanning calorimetry, field-emission scanning electron microscopy, x-ray diffraction analysis, contact-angle measurement, tensile testing, pencil hardness, gloss, etc. In addition, the curing kinetics of the resin was analysed to evaluate the kinetic parameters such as, reaction rate, activation energy and degree of conversion in terms of time and temperature. Result analyses through RSM revealed a desirability of 0.985 for the reaction time of 88.64 min. Moreover, 91.5% fractional conversion was achieved actually, which is close to the predicted value. Analysis revealed that 3,4,5,6-tetrahydophthalic anhydride-based resin showed improved resinous property than others due to high degree of crosslinking. It was also found that higher amount of aliphatic acid anhydrides are responsible for high degree of crosslinking density, whereas higher thermal stability was ensured by the inclusion of aromatic acid anhydride. Finally, incorporation of MWCNTs into the alkyd resin enhanced the overall film properties, which was further improved through in-situ reaction. The physical bonding and mechanical entanglement were the possible reason for showing improved properties, as revealed from the analysis
Effects of nanosilica and titanium oxide on the performance of epoxy–amine nanocoatings
Get PDFDifferent types of composite coatings were prepared by the blending of colloidal nanosilica (SiO2) and titanium dioxide (TiO2) in epoxy resin to investigate their coating performances. A fixed amount of silica nanoparticles (20 wt %) and different amounts (5, 10, and 15 wt %) of microsized TiO2 particles were used in the coatings. The functional groups of the formulated coatings were confirmed by Fourier transform infrared spectroscopy. These results indicate that the SiO2–TiO2 particles interacted well with epoxy. Scanning electron microscopy images of the composite coatings revealed a good dispersion of TiO2 particles at a lower amount of loading; this improved the adhesiveness, glass‐transition temperature, thermal stability, and chemical resistance properties. At higher loadings, the performances decreased. The composite coatings were also characterized by their UV radiation‐absorption properties with an ultraviolet–visible spectrophotometer. Interestingly, this property was found to be enhanced at higher loadings. An impressive result was noticed in the nanocomposites in terms of oxygen transmission rate performance compared to that of the neat epoxy
Dispersion characteristics of hydroxyl and carboxyl-functionalized multi-walled carbon nanotubes in polyester nanocomposites
Get PDFMulti-walled carbon nanotube (MWCNT) reinforced polyester-based composites were prepared by mixed blending in a solvent. Orthophthalic unsaturated polyester was blended individually with different types of non-functionalized and functionalized MWCNTs. Two types of functional groups: hydroxyl (-OH) and carboxyl (-COOH) were introduced with MWCNTs for the nanocomposites. The mechanical properties of the composites, like tensile, three-point bending and impact energy were evaluated. Fourier transform infrared spectroscopy was used for the functional group analysis. The dispersion characteristics of the samples were observed by transmission electron microscopy and field-emission electron microscopy. In addition, the thermal decomposition and melting behavior of the samples was assessed by differential scanning calorimetry and thermogravimetric analysis. The properties were varied due to the variation of the functional groups. The result analysis showed that the entangled agglomerations of hydroxyl-functionalized MWCNTs were destroyed to relatively smaller clusters. The hydroxyl-functionalized MWCNTs were more effective for homogeneous dispersion and contributed for better mechanical properties of the composites, compared to non-functionalized and carboxyl group-functionalized MWCNTs
Dispersion characteristics of hydroxyl and carboxyl-functionalized multi-walled carbon nanotubes in polyester nanocomposites
No full textAbstract
Multi-walled carbon nanotube (MWCNT) reinforced polyester-based composites were prepared by mixed blending in a solvent. Orthophthalic unsaturated polyester was blended individually with different types of non-functionalized and functionalized MWCNTs. Two types of functional groups: hydroxyl (-OH) and carboxyl (-COOH) were introduced with MWCNTs for the nanocomposites. The mechanical properties of the composites, like tensile, three-point bending and impact energy were evaluated. Fourier transform infrared spectroscopy was used for the functional group analysis. The dispersion characteristics of the samples were observed by transmission electron microscopy and field-emission electron microscopy. In addition, the thermal decomposition and melting behavior of the samples was assessed by differential scanning calorimetry and thermogravimetric analysis. The properties were varied due to the variation of the functional groups. The result analysis showed that the entangled agglomerations of hydroxyl-functionalized MWCNTs were destroyed to relatively smaller clusters. The hydroxyl-functionalized MWCNTs were more effective for homogeneous dispersion and contributed for better mechanical properties of the composites, compared to non-functionalized and carboxyl group-functionalized MWCNTs.</jats:p
Effects of nano-and micro-sized inorganic filers on the performance of epoxy hybrid nanocoatings
Get PDFEpoxy-based composite coatings were prepared using nanosilica (silicon dioxide (SiO2)) and zinc oxide (ZnO). Different concentrations (5.0, 10.0 and 15.0 wt%) of micro-sized ZnO particles were used along with a fixed amount (20.0 wt%) of nanosilica particles. The functional groups of the composite coatings were confirmed by the Fourier transform infrared spectroscopy. This result indicated that SiO2–ZnO particles were cross-linked with the epoxy. The scanning electron microscopy images of the samples revealed a good dispersion of ZnO particles. In addition, the samples showed an improved adhesive and chemical resistance properties as measured by the cross-cut tape test and chemical resistivity testing. At higher loading of ZnO, the composite coating showed poor properties. Besides that, thermogravimetric analysis, differential scanning calorimetry and ultraviolet–visible spectrophotometer were used to characterize the composite coatings. The properties were enhanced at higher loading of ZnO particles. The oxygen transmission rate was also impressive compare with the neat epoxy
SMART DEAF-MUTE GLOVE
Get PDFGenerally, people with speech or deafness have a problem in everyday communication with others. They can only interact with Sign Language as the main way to interact with others. Moreover, only a few people understand this Sign Language and a few others do not understand it, it is very difficult for these people with disabilities to deliver the message they want to fulfil. Somepeople will interact more strongly because they have a "deaf voice" and this attitude will make them unpopular. That is the nature of their self. Thus, the gloves equipped with flex sensors that have been created to overcome the shortcomings of these deaf and dumb people. The existence of these sophisticated tools has given a little help to the dumb and deaf. Communicating with the whole world, this tool will convert Sign Language (hand gestures) that is understood by the deaf and dumb to the Common Language that everyone understands and it can be programmed with all languages in the world as a result of the cooperation of all countries to make this tool available to all corners. The exception of the flex sensor on the glove works to stream the dataaccording to the angular or degree motion of the flex sensor itself created or moved by the finger of the wearer. The flex sensor has different resistance and this depends on the amount of angle or degree to which the wearer moves, the more the finger moves the more resistance value is produced. Then, the resulting output will be converted into digital form by the microcontroller and it respondsthrough user’s phone
Alkyd Based Resin from Non-drying Oil
No full textAbstractPalm oil-based alkyd resins were synthesized by alcoholoysis and esterification reactions. Calcium oxide was used as a catalyst for the alcoholysis reaction between palm oil and glycerin. Esterification process was carried out by using phthalic anhydride and maleic anhydride. Physico-chemical properties of the resins such as density, viscosity, acid value, iodine value, saponification value, specific gravity, and moisture content were measured following ASTM and standard methods. The structural confirmation and hydrogen density of the prepared resins were determined by Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, respectively. Molecular weight of the resins was determined by using gel permeation chromatography. The curing process involved heating at 140oC, without using any organic solvent in the presence of methyl ethyl ketone peroxide and cobalt-napthenate. ASTM methods were followed to measure the gloss, hardness and chemical resistivity of the resins. Temperature behaviors were observed by differential scanning calorimetry and thermogravimetric analysis. Produced resins were found thermally stable (up to 300oC). The variations of the properties were noticed due to the types of anhydrides in terms of molecular weight, thermal and chemical resistivity of the resins, although the other properties were found close to each other. Overall, the reported properties are found suitable for the materials to be used for surface coating applications
Comparative analysis of the properties: microcrystalline cellulose fiber polyamide composites filled with ethylene copolymer and olefin elastomer
Get PDFPolyamide 6.10 (PA) composites, reinforced with microcrystalline cellulose fibers, were prepared separately using two types of coupling agents, Exxelor VA1803 (VA) and Bondyram 7103 (BR), using extrusion followed by an injection molding process. The fiber loading was fixed to 30 wt%, whereas the coupling agent was fixed to 5 wt%. The properties of the composites were characterized by the tensile properties, impact testing, differential scanning calorimetry, dynamic thermomechanical, thermogravimetric, and X-ray diffraction analyses. The distribution of the fibers into the PA was examined by a scanning electron microscope. It was found that the VA improved the mechanical and thermomechanical properties slightly compared to BR-based samples. Overall, the structural, morphological, and thermal properties of the composites were also improved comparatively using VA
