Showing papers on "SISAL published in 2013"

Mechanical property evaluation of sisal–jute–glass fiber reinforced polyester composites

Abstract: The composite materials are replacing the traditional materials, because of its superior properties such as high tensile strength, low thermal expansion, high strength to weight ratio. The developments of new materials are on the anvil and are growing day by day. Natural fiber composites such as sisal and jute polymer composites became more attractive due to their high specific strength, lightweight and biodegradability. Mixing of natural fiber with Glass-Fiber Reinforced Polymers (GFRPs) are finding increased applications. In this study, sisal–jute–glass fiber reinforced polyester composites is developed and their mechanical properties such as tensile strength, flexural strength and impact strength are evaluated. The interfacial properties, internal cracks and internal structure of the fractured surfaces are evaluated by using Scanning Electron Microscope (SEM). The results indicated that the incorporation of sisal–jute fiber with GFRP can improve the properties and used as a alternate material for glass fiber reinforced polymer composites.

The effect of fiber morphology on the tensile strength of natural fibers

Abstract: In the present work the morphology of natural fibers was correlated with their mechanical properties via image analysis. Jute, sisal, curaua, coir and piassava fibers were tested under direct tension in a universal testing machine and the cross-sectional areas of the fibers were calculated using images obtained in a scanning electron microscopy. For the jute fiber the tests were performed for several gage lengths in order to investigate its influence on the tensile strength and to compute the machine compliance. For sisal, jute and curaua fibers the amount of fiber-cells, the size of the cell walls and the real area of the fibers were measured and their correlation with the tensile strength addressed. The curaua fiber presented the highest mechanical performance with tensile strength and Young’s modulus of 543 MPa and 63.7 GPa, respectively. Weibull statistical analysis was used to quantify the variability of fiber strength. The sisal fibers presented the highest Weibull modulus (3.70), whereas the curaua presented the lowest one (m = 2.2), which means that the sisal had the lowest variability and curaua the highest.

Degradation kinetics and aging mechanisms on sisal fiber cement composite systems

Abstract: The kinetics of vegetable (sisal) fiber degradation and the mechanisms responsible for deterioration of continuous sisal fiber cement composites are presented in this paper. Two matrices were used: one with 50% partial cement replacement by metakaolin (PC–MK) and a reference matrix having as binder only Portland cement (PC). The durability performance of the composite systems is examined and the mechanisms for the significant delay in the fiber degradation when the total amount of calcium hydroxide is reduced from the matrix discussed. The composites were subjected to 5, 10, 15, 20 and 25 cycles of wetting and drying and then tested under a four point bending load configuration in order to determine the flexural behavior and cracking mechanisms with progressive aging. Furthermore, composites stored under controlled lab conditions were tested under bending load at ages ranging from 28 days to 5 years. Fibers extracted from the aged composites were subjected to thermal analysis, Fourier transform infrared spectroscopy and microscopical observations in order to evaluate the changes in chemical composition and microstructure. Two fiber degradation mechanisms were observed in the PC composites: fiber mineralization due to the precipitation of calcium hydroxide in the fiber cell and surface and degradation of cellulose, hemicellulose and lignin due to the adsorption of calcium and hydroxyl ions. The degradation process occurs rapidly and after 10 cycles of wetting/drying a quite expressive modification in the flexural behavior is observed. The residual mechanical parameters after 25 cycles were the same as those observed in the unreinforced matrix. For the PC–MK composite fiber mineralization was not observed due to the low content of CH in the matrix.

Natural Fiber Reinforced Polymer Composites for Automobile Accessories

Abstract: The invention is an effort to utilize the advantages offered by renewable resources for the development of composite materials based on polymer and particles of natural fibers for Conservation of natural resources. In this research, natural fibers like Sisal (Agave sisalana), Banana (Musa sepientum) and Roselle (Hibiscus sabdariffa), Sisal and banana (hybrid), Roselle and banana (hybrid) and Roselle and sisal (hybrid) are fabricated with bio epoxy resin using molding method. The applications of these materials require a sustainable approach to creating green products. Green materials are very important to form environment friendly from renewable resources and decrease the use of petroleum based chemicals. Nowadays natural fibers form an interesting alternative for the most widely applied fibre in the composite technology, glass. The use of fibers like sisal, Roselle and banana in this industry so far is small since availability of a durable semi-finished product with constant quality is often a problem. Recent research and development have shown that these aspects can be improved considerably. Knowing that natural fibers are cheap and have a better stiffness per weight than glass, which results in lighter components, the grown interest in natural fibers is clear. Secondly, the environmental impact is smaller since the natural fibre can be thermally recycled and fibers come from a renewable resource. Their moderate mechanical properties restrain the fibers from using them in high-tech applications, but for many reasons they can compete with glass fibers. In this paper the optimum mixing of fiber and resin is achieved by using Taguchi method. In this work, tensile and hardness of Sisal and banana (hybrid), Roselle and banana (hybrid and Roselle and sisal (hybrid) composite at dry and wet conditions were studied. Hardness test were conducted using Brinell hardness testing machine. In this work micro structure of the specimens are scanned by the Scanning Electron Microscope. The disclosure includes the process to make the composite and also the variety of products in automobile accessories.

Effect of Mercerization and Benzoyl Peroxide Treatment on Morphology, Thermal Stability and Crystallinity of Sisal Fibers

Abstract: Studies on the use of natural fibers as replacement to man-made fiber in fiber-reinforced co mposites have increased and opened up further industrial possibilities. Natural fibers have the advantages of low density, low cost, and biodegradability. However, the main d isadvantages of natural fibers in co mposites are the poor co mpatibility between fiber and matrix and the relative high mo isture sorption. Therefore, chemical treat ments are considered in modify ing the fiber surface properties. In this study, Sisal fibers were modified using alkali and benzoyl pero xide solution of different concentration for different time intervals. Morphological changes, thermal stability and crystallinity of fibers were investigated using scanning electron microscope (SEM), TGA and XRD technique. Thermal stability of sisal fibers were decreased on mercerization. Whereas, sisal fibers treated with benzoyl pero xide the enhanced thermal stability. In case of XRD studies, sisal fibers show enhanced crystallin ity.

Mechanical Properties of Natural Fibre (Banana, Coir, Sisal) Polymer Composites

Abstract: Natural fibres have been used to reinforce materials for over 3000 years. More currently they have been employed in combination with plastics. Many types of natural fibres have been investigated for use in plastics including flax, hemp, jute, sisal and banana. Natural fibres have the advantage that they are renewable resources and have marketing appeal. These agricultural wastes can be used to prepare fibre reinforced polymer composites for commercial use. Application of composite materials to structures has presented the need for the engineering analysis the present work focuses on the fabrication of polymer matrix composites by using natural fibres like coir,banana and sisal which are abundant nature in desired shape by the help of various structures of paterns and calculating its material characteristics(flexural modulus, flexural rigidity, hardness number,% gain of water) by conducting tests like flexural test, hardness test, water absorption test, impact test, density test, and their results are measured on sections of the material and make use of the natural fibre reinforced polymer composite material for automotive seat shell manufacturing.

Effect of fiber morphology on rheological properties of plant fiber reinforced poly(butylene succinate) composites

Abstract: Sisal fibers (SFs), steam exploded sisal fibers (SESFs) and steam exploded bagasse fibers (SEBFs) which have different fiber morphologies, were mixed with poly(butylene succinate) (PBS) using a torque rheometer. The rheological properties of these plant fiber-reinforced PBS composites were evaluated. Results show that the fiber morphology has a large effect on rheological behavior. At the same fiber content (e.g., 10 wt% and 30 wt%), the non-Newtonian index n of composites reinforced by flexible fibers with a higher aspect ratio and larger contact area with the matrix is smaller. In general, n decreases with increasing fiber content but when the fiber content is too high (e.g., 50 wt%), the aggregation of fibers is too extensive so that the actual contact area between fibers and matrix becomes much lower, n increase instead. At the same fiber content (e.g., 10 wt% and 30 wt%), the consistency indices of fibrous filler-reinforced composites are larger than those of powder-filled composites; the larger the actual contact area between the matrix and the fibers, the greater the consistency index of the composite.

TPS/PCL Composite Reinforced with Treated Sisal Fibers: Property, Biodegradation and Water-Absorption

Abstract: Sisal fibers bleached with sodium-hydroxide followed by hydrogen peroxide treatment were incorporated in a thermoplastic starch/e-polycaprolactone (TPS/PCL) blend via extrusion processing. These samples with smooth and homogenous surfaces were examined for their property, biodegradability and water absorption. Scanning electron microscopy revealed that the fibers were well dispersed in the matrix. In addition, it was found that the fibers and matrices interacted strongly. Blends with 20 % (dry weight-basis) fiber content showed some fiber agglomeration. Whereas blends with 10 % fibers showed increased crystallinity and lower water absorption capacity. The CO2 evolution study showed that the thermoplastic starch samples without any additives had the highest rate and extent of degradation whereas the neat PCL samples had the lowest degradation rate. Addition of fiber to the TPS/PCL blend exhibited the degradation rates and extents that were somewhere in between the pure TPS and neat PCL. This work demonstrates that TPS/PCL composites reinforced with bleached sisal has superior structural characteristics and water resistance and thus, can be used as polymeric engineering composites for different applications.

Thermal and dynamic mechanical properties of bio-based poly(furfuryl alcohol)/sisal whiskers nanocomposites

Abstract: In this study, bio-based nanocomposites of sisal whiskers-reinforced poly(furfuryl alcohol) (PFA) were prepared using an in situ polymerization method. Furfuryl alcohol (FA), which is a derived renewable monomer, was used to serve first as a solvent to disperse the whiskers and later as a monomeric precursor to produce PFA. Sisal whiskers were prepared via acid hydrolysis, which was followed by freeze-drying and re-dispersion of the dried whiskers in FA by sonication for 20 min. The polymerization process was catalysed using citric acid, which is also a renewable carboxylic acid found in citrus fruits. The effect of increased sisal whiskers loading on the thermal and dynamic mechanical properties of the nanocomposites was investigated using thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The TGA results showed slightly higher thermal stability for the nanocomposite samples compared to neat PFA. The DMA results showed that the incorporation of sisal whiskers imparts significant enhancement in the storage modulus of the PFA matrix. Moreover, the intensity of the tan δ peak at ~75 °C for the nanocomposites was remarkably reduced compared to that of neat PFA.

Compressive stress-strain behaviour of cement mortar-composites reinforced with short sisal fibre

Abstract: To design building elements using sisal fibre reinforced mortar composites, the stress-strain curves of the composites both under tensile and compression load is needed. In this study short sisal fibre-cement based composites were developed and their stress-strain behaviour under compression characterized experimentally. The composites consisted of two mortar matrices, one self-compacting and one of normal consistency, reinforced with randomly distributed short sisal fibre (25 and 50 mm long) in volume fractions ranging from 2% to 6%. Based on the experimental results a compressive constitutive law for the composites was proposed based on the damage theory developed by Mazars (1986). This theory was used to model the ascending branch of the stress-strain curve and a damage parameter associated to the fibre-reinforcing index is proposed to allow the modelling of the post-peak behaviour of the composites. The modified model was then validated using results available in the literature. The experimental results obtained in the study indicated that the addition of short sisal fibres to cement matrices tends to reduce its elastic modulus, peak stress and strain and to increase its toughness. However, the use of a self-compacting matrix allowed better sisal fiber dispersion and composites with superior performance were obtained. The modified analytical model was able to predict with good accuracy the ascending and descending branch of the stress-strain curves of the sisal fiber-mortar composites and allowed evaluating the effect of fibre reinforcing index on material damage. In the ascending branch, an increase in the damage from 40% to 70% is recorded for fiber volume ranging from 2 to 6%. In the descending branch, on the other hand, the variation of fiber volume allowed a reduction of the damage from 65% to 60%.

Short beam strength of curaua, sisal, glass and hybrid composites

Abstract: In this study, the short beam strength characteristics of randomly oriented composites were comprehensively investigated. The following parameters were varied: fiber used (curaua or sisal), fiber washing or surface chemical treatment with sodium hydroxide/sodium borohydride, fiber length (from 5 to 60mm), hybridization with glass fiber and the preprocessing of the polyester resin. The overall fiber volume fraction was kept constant (30vol.%). In all configurations, the composites containing curaua fiber obtained higher short beam strength than those with sisal. An increase in fiber length yielded higher short beam strength. The optical and electronic micrographs showed mostly horizontal cracks, typical of shear failure. In addition, it was carried out a study of the ASTM D2344 standard regarding the span-to-thickness ratio recommended for testing, the measured strength decreased for higher span-to-thickness ratio for specimens with higher length and width, and the failure mode changed to bending around span-to-thickness >12.

Cultivation of Oyster Mushroom (Pleurotus HK-37) On Solid Sisal Waste Fractions Supplemented With Cow Dung Manure

Abstract: Solid sisal waste fractions which included composted sisal boles and sisal leaves decortication residues supplemented with cow dung manure at various rates used singly and/or in combination as substrates were investigated for cultivation of oyster mushroom ( Pleurotus HK-37). The effect of the test sisal waste substrates and cow dung manure of various supplementation rates were evaluated by mushroom yield, biological efficiency and mushroom size. Pinheads occurred in all substrates within 3 to 5 weeks of transfer of bags to the cropping room. The overall best results of mushroom production were obtained in a substrate combination of 50 % sisal leaves + 50 % sisal boles (based on 450 g wet weight substrate) supplemented by 30 % cow dung manure with the mushroom yield of 184.64 g fresh mushrooms/kg moist substrate weight and percentage biological efficiency (B.E) of about 63 %. Mushroom size of 6.10 was obtained in sisal boles substrate supplemented by 20 % cow dung manure. Least yield of 26.73 g fresh mushrooms/kg moist substrate weight and lowest B.E of 8.95 % were obtained from non-supplemented substrate of sisal leaves alone. The study concluded that, supplementation using cow dung manure may play an important role on increasing the yield and productivity of Pleurotus HK-37 on solid sisal waste fractions under the conditions investigated.

Electrical and mechanical properties of the potassium permanganate treated short sisal fiber reinforced epoxy composite in correlation to the macromolecular structure of the reinforced fiber

Abstract: Sisal fibers are treated with potassium permanganent (KMnO4)—acetone solution for various concentrations for different soaking time period prior to the composite fabrication. Small angle X-ray scattering (SAXS) and wide angle X-ray diffraction (WAXD) analysis shows significant change in the macromolecular and the crystallographic parameters of the fiber, respectively, after the treatment. Fiber treated with 0.05% KMnO4-acetone solution for 2 min (05K2) is found to have highest degree of crystalinity, crystallite size, and bulk density. Enhanced tensile and flexural strength of the 05K2 reinforced epoxy composite (05KC2) is attributed to the increase surface roughness of the fiber. Lower values of dielectric constant (er), dielectric loss (tan δ) and improved volume resistivity (ρ) for the 05KC2 composite may be due to the hindered molecular motion of the polymeric chains at the composite interface resulting from the better interlocking between the fiber and matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Mechanical Characterization of Banana/Sisal Fibre Reinforced PLA Hybrid Composites for Structural Application

Abstract: Advanced technology emergence in the field of petrochemical-based polymers has brought many benefits to mankind It is validating that the ecosystem is considerably disturbed and damaged as a result of the non-degradable plastic materials used for disposable items This paper relates the use of hybrid bio-composites, which is eco-friendly and easily degradable Previous literature related to hybrid bio-composites proves its eco-friendly and excellent degradable properties In this paper, banana and sisal fibers were selected to execute the hybrid bio-composite preparation with poly lactic as its matrix Specimens were made with and without fibre treatment and their mechanical properties like tensile, flexural and impact were evaluated as per the standard test procedures The test results obtained evident that the treated fibers having the best mechanical properties than pure PLA and untreated fibre bio-composites The chemical treatment also improved fiber matrix interaction by removal of lignin and hemicellulose, which led to the better incorporation of fiber with the matrix The SEM micrographs of untreated banana/sisal fibre reinforced PLA bio-composites and treated banana/sisal fibre reinforced PLA bio-composites clearly indicated the extent of the fiber-matrix interface adhesion

Production of cellulose-degrading enzyme on sisal and other agro-industrial residues using a new Brazilian actinobacteria strain Streptomyces sp. SLBA-08

Abstract: Several types of lignocellulosic raw materials including wheat straw, sisal bagasse and sugarcane bagasse have different contents of cellulosic components. In our studies, aimed at isolating cellulose-degrading actinobacteria from Brazilian soils, a promising strain was selected and identified as Streptomyces sp. SLBA-08. This strain was tested for cellulase production under submerged fermentation in a mineral medium using different carbon sources (sisal bagasse, sugarcane bagasse and straw), as well as ammonium sulphate in different concentrations as nitrogen source. The results showed that medium containing 2.4% (w/v) sisal bagasse and 0.3% (w/v) ammonium sulphate resulted in the highest production of carboxymethylcellulase (1.11 U mL-1), after 48 hours. The pH and temperature profile showed optimal activity at pH 6.0 and 50 °C. As for thermostability, carboxymethylcellulases were tolerant at 50 °C, retaining 70% of the maximal activity even after 2h of incubation. The results obtained indicate that Streptomyces sp. SLBA-08 was capable of producing CMCase using lignocellulosic residues, especially sisal bagasse.

Mechanical characterization of sisal fiber-reinforced recycled HDPE composites

Abstract: The increasing awareness of the environment protection has contributed to concerns regarding alternative procedures for recycling of plastic wastes. Since chemical processes are high cost, energy and often environment harmful, thermo-mechanical techniques of recycling rises as a good alternative. This research deals with mechanical characterization of thermo-mechanical recycling of composites based on recycled high density polyethylene (HDPE) from post-consumed motor-oil plastic containers as matrix and natural fibers (sisal) as reinforcement. The composites were made by extrusion and then melt blended in a compression mold. The sisal fibers do not contribute to increase tensile strength. As fiber content increases loss of ductility is observed.

Effect of Silica on Thermal and Mechanical Properties of Sisal Fiber Rein- forced Polyester Composites

Abstract: The main objective of this paper is to investigate effect of silica on thermal and mechanical properties of sisal natural fiber reinforced polyester composites. The composites with and with out silica have been made by incorporating 100% biodegradable sisal fibers as reinforcement in the polyester matrix. The results show that the tensile strength and tensile modulus of composite with silica are 1.5, and 1.08 times greater than that of composite without silica, respectively. The impact strength of composite with sand is 1.36, and 1.8 times greater than that of composite with out silica and plain polyester, respectively. The effect of silica on specific heat capacity of composite is also considered and discussed.

Effect of silver coating on electrical properties of sisal fibre-epoxy composites

Abstract: In this paper, the effect of silver coating and size of fibre on electrical properties of sisal fibre-reinforced epoxy composites has been reported. For this purpose, epoxy composites reinforced with silver-coated sisal (of 5 and 10 mm length) prepared by hand moulding and samples were characterized for their electrical properties, such as dielectric constant (e′), dielectric dissipation factor (tan δ) and AC conductivity (σ ac), at different temperatures and frequencies. It was observed that dielectric constant increases with increase in temperature and decreases with increase in frequency from 500 Hz to 5 kHz. The peak height at the transition temperature decreases with increasing frequency. Interestingly, sample having silver-coated fibre of 5 mm length exhibited higher value of dielectric constant as compared to the sample having 10 mm of fibre length, which is attributed to the increased surface area of coated fibre. This behaviour of the material can be explained in terms of interfacial polarization. At a constant volume of fibres and at a length of 5 mm, the number of interfaces per unit volume element is high and this results in high interfacial polarization. The number of interfaces decreases as the fibre length increases and therefore the value of e′ decreases at 10 mm fibre length. To study the changes in structure of samples, Fourier transform infrared spectrometry and scanning electron microscopy of the samples were carried out.

Surface treatment of sisal fiber composites for improved moisture and fatigue properties

Abstract: This paper presents the effect of moisture on fatigue properties of untreated and NaOH-clay-treated sisal fiber-reinforced epoxy and polypropylene (PP) composites. Sisal fibers were reinforced in e...