Showing papers on "SISAL published in 2011"
TL;DR: In this paper, the tensile, flexural, impact and water absorption tests were carried out using a banana/epoxy composite material, and the optimum fiber length and weight percentage were determined.
416 citations
TL;DR: In this paper, the experiments of tensile and flexural tests were carried out on composites made by reinforcing jowar as a new natural fibre into polyester resin matrix.
364 citations
TL;DR: In this paper, the sisal fibers were modified by alkali solutions of NaOH (5% and 10%) and bleached with sodium hyplochlorite NaClO/H2O (1:1) at 60-75°C.
Abstract: The sisal (Agave sisalana) is a cellulosic fiber produced in Brazil since 1903 and until now has been one of the most traded due to its characteristics such as the low cost, low density, specific resistance, biological degradability, CO2 neutrality, renewability, good mechanical properties, non-toxicity and furthermore can be easily modified by a chemical agent improving their mechanical and thermal properties. In this work, the sisal fibers were modified by alkali solutions of NaOH (5% and 10%) and bleached with sodium hyplochlorite NaClO/H2O (1:1) at 60–75 °C. It was used as reinforcing agent in the preparation of phenolic matrix composites derived from cashew nut shell liquid (CNSL). The chemical treatment improved the thermal stability of the weight loss process for sisal treated with NaOH 5% in about 12 °C and for sisal treated with NaOH 10% in about 18 °C when compared to sisal fiber in its raw state. It was also observed a variation of 15 °C when comparing the composite reinforced by raw sisal with composite reinforced with sisal treated NaOH 10%.
179 citations
TL;DR: It is revealed that chemical activation of sisal wastes with K(2)CO(3) allows obtaining samples suitable for pharmaceutical compounds removal from liquid phase, and the removal efficiency of prepared samples attained values comparable to a commercial carbon.
139 citations
TL;DR: In this article, the thermal degradation characteristic was established to five selected wastes (coffee husks, sisal bole, cashew nut shells, palm stem, and bagasse) using a thermogravimetric analyzer type NETZSCH STA 409 PC Luxx at a heating rate of 10 K/min.
119 citations
TL;DR: In this paper, the transcrystalline effects at poly(lactic acid) (PLA) matrix caused by various sisal fibres, which were untreated (U-sisal), or treated with alkali (A-sal) and silane (S-salinamide) were evaluated.
Abstract: The focus of this work was to evaluate the transcrystalline effects at poly(lactic acid) (PLA) matrix caused by various sisal fibres, which were untreated (U-sisal), or treated with alkali (A-sisal) and silane (S-sisal). Isothermal crystallization was performed at temperatures between 123 and 130 °C using polarized optical microscopy. Results showed that the sisal fibres untreated or treated all had a nucleating ability to transcrystallize in PLA matrix. Based on the theory of heterogeneous nucleation, the interfacial free energy difference functions Δσ were determined to be 0.68, 0.65, and 0.65 erg/cm2 for PLA/U-sisal, PLA/A-sisal and PLA/S-sisal, respectively. This suggests that the fibre surface modification by using alkali or silane has little or no influence to the nucleation ability of sisal fibre in PLA matrix.
113 citations
TL;DR: In this article, the water vapour sorption kinetic properties of cotton, filter paper, flax, hemp, jute, and sisal fibres were determined using a dynamic vapour Sorption apparatus and the results were analyzed by use of a parallel exponential kinetics model.
Abstract: Hygroscopic behaviour is an inherent characteristic of natural fibres which can influence their applications as textile fabrics and composite reinforcements. In this study, the water vapour sorption kinetic properties of cotton, filter paper, flax, hemp, jute, and sisal fibres were determined using a dynamic vapour sorption apparatus and the results were analyzed by use of a parallel exponential kinetics (PEK) model. With all of the fibres tested, the magnitude of the sorption hysteresis observed varied, but it was always greatest at the higher end of the hygroscopic range. Flax and sisal fibres displayed the lowest and highest total hysteresis, respectively. The PEK model, which is comprised of fast and slow sorption components, exhibited hysteresis in terms of mass for both processes between the adsorption and desorption isotherm. The hysteresis derived from the slow sorption process was less than from the fast process for all tested fibres. The fast processes for cotton and filter paper dominated the isotherm process; however, the hemp and sisal fibres displayed a dominant slow process in the isotherm run. The characteristic time for the fast sorption process did not vary between adsorption and desorption, except at the top end of the hygroscopic range. The characteristic time for the slow process was invariably larger for the desorption process. The physical interpretation of the PEK model is discussed.
111 citations
TL;DR: It was shown that the pre-enzymatic hydrolysis treatment of bleached sisal pulp helps the preparation of well individualized rod-like nanocrystals and both tensile tests and dynamic mechanical analyses showed improved stiffness for all nanocomposites.
Abstract: In a previous work (Siqueira et al. 2010b) the preparation of cellulosic nanoparticles from sisal fibers using different processing routes, viz. a combination of mechanical shearing, acid and enzymatic hydrolysis was reported. It was shown that the pre-enzymatic hydrolysis treatment of bleached sisal pulp helps the preparation of well individualized rod-like nanocrystals. An amorphous polymer (natural rubber—NR) was chosen as model matrix to investigate the effect of these nanoparticles on the thermo-mechanical properties of nanocomposites. Both tensile tests and dynamic mechanical analyses showed improved stiffness for all nanocomposites. The enzymatic treatment allowed production of a huge range of cellulosic nanoparticles which provided completely different mechanical properties to NR matrix.
109 citations
TL;DR: In this article, the effect of curing age and fiber embedment length on the fiber-matrix interface was studied and it was found that the sisal fiber morphology plays an important role in the bond strength.
Abstract: An experimental investigation was performed to understand the pull-out behavior of sisal fibers from a cement matrix. The effect of curing age and fiber embedment length on the fiber–matrix interface was studied. Sisal fiber presents irregular cross-section with different shapes that may be beneficial for the bond strength. A scanning electron microscope coupled with image analysis was used to measure the cross-section area of individual tested fibers and to determine and classify their morphology. The results were correlated to the fiber morphology. Direct tension tests were performed on composites reinforced by 10% in volume of continuous aligned sisal fiber. A finite difference model developed earlier by authors was used to determine the bond strength versus slip constitutive relation from experimental data and to predict the composite tensile behavior and crack spacing. It was found that the sisal fiber morphology plays an important role in the bond strength. Average adhesional bond strength as high as 0.92 MPa were reported for the fiber shape that promoted the best interfacial performance.
107 citations
TL;DR: In this paper, the fiber length and aspect ratio distributions in polypropylene composites were characterized using high resolution optical microscopy coupled with image analysis software and statistical methods, and the results showed that the presence and amount of elementary fibres, fibre bundles and particles were found.
Abstract: Using high resolution optical microscopy coupled with image analysis software and statistical methods, fibre length and aspect ratio distributions in polypropylene composites were characterized. Three types of fibres, flax, sisal and wheat straw, were studied. Number and surface weighted distributions were used to demonstrate the presence and amount of elementary fibres, fibre bundles and particles. A large number of small particles that are usually not taken into account were found. The obtained fibre length and aspect ratio distributions were successfully fitted by a two-parameter Weibull model. No significant effect of fibre concentration on the length and aspect ratio distributions was detected for 20% and 40% flax-based composite. Fibre type was found to be a very important parameter influencing size and shape distributions: flax is broken into long elementary fibres, sisal-based composite contains non-dispatched bundles and elementary fibres and wheat straw-based composite has bundles and large and small particles.
89 citations
TL;DR: In this article, the use of natural fibers as reinforcement in polymeric composites for technical applications has been a research subject of scientists during the last decade, motivated by potential advantages of weight saving, lower raw material price, and ecological advantages of using green resources which are renewable and biodegradable.
TL;DR: In this article, the use of Agave sisalana (sisal fiber) as an natural adsorbent for ions Pb(II) and Cd(II), was proposed.
TL;DR: In this article, surface microfibrillation of sisal fiber to a DM value of 24 °SR increased the tensile strength, internal bonding strength and wear resistance values of composites by 93%, 124% and 31%, respectively.
Abstract: Surface microfibrillation of cellulose fibre was adopted as a facile method for improving cellulose fibre/phenolic resin interfacial adhesion in hybrid composites composed of sisal fibre and aramid fibre. Development of microfibrils and aggregates on the fibre surface significantly increased the interfacial adhesion between the sisal fibre and resin by providing a large contact area and by inhibiting the formation of spontaneous cracks in the composites. Consequently, the compression, tensile and internal bonding strengths, and wear resistance of the hybrid composites were remarkably improved. Surface microfibrillation of sisal fibre to a DM value of 24 °SR increased the tensile strength, internal bonding strength and wear resistance values of composites by 93%, 124% and 31%, respectively.
TL;DR: In this article, the use of natural fibers in mixture of type SMA was analyzed and the results of mechanical tests (tensile strength and modulus of resilience) demonstrate that blends with natural fibers showed high resistance, while preventing the asphalt to drain down.
TL;DR: In this article, groundnut shell particles were chemically modified and added to the polymer to form novel bio-based composites and the composites were characterized for some mechanical properties according to ASTM standards.
Abstract: In recent years, there is a growing interest in the use of bio-fibers as reinforcements for thermoplastics and thermosets. A lot of research work has been performed all over the world on the use of natural fibers such as flax, bamboo, sisal, hemp, and jute as reinforcing materials for the preparation of various types of composites. In this study, the agricultural residue such as groundnut shell particles were chemically modified and added to the polymer to form novel bio-based composites. Composite boards were fabricated by randomly distributed groundnut shell particles of different grain sizes and epoxy resin with volume percentages of 70:30, 65:35, and 60:40. The composites prepared were characterized for some mechanical properties according to ASTM standards. The highest tensile strength, tensile modulus, MOR, and impact strength were observed for the sample having groundnut shell particles and epoxy resin proportion 60:40 and 0.5 mm particle size. However, the sample with 60:40 particles and resin pro...
TL;DR: In this article, the effect of surface treatment on tensile, flexural and chemical resistance properties of sisal fiber reinforced composites was studied for natural ligno cellulosic sisal fibre reinforced composite.
Abstract: In this study, effect of fibre surface treatment on tensile, flexural and chemical resistance properties were studied for sisal fibre reinforced composites Natural ligno cellulosic sisal fibre reinforced composites were prepared by different surface treatments by hand lay-up method Fibre surface treatments were carried out to produce good interface between the fibre and the matrix to improve the mechanical properties Fibre surface treatments were done by boiled the sisal fibres in different % of NaOH and treated the fibres in different % of NaOH, treated in acetic acid and methanol Unsaturated polyester resin was used as the matrix for preparing the composites For comparison, these properties for untreated sisal fibre reinforced composites were also studied From the results it was observed that 18% aqueous NaOH boiled sisal fibre reinforced composites have higher tensile, flexural properties than other composites Untreated sisal fibre composites show lower properties than treated composites Chemical resistance properties indicate that all sisal fibre reinforced composites are resistance to all chemicals except carbon tetra chloride The tests are carried out as per the ASTM standards
TL;DR: In this article, high cellulose content sisal fibers were treated with laccase from Trametes villosa and a varying amount of TEMPO in order to evaluate the potential of Laccase-TEMPO system to improve the paper physical properties of pulp fibers.
TL;DR: In this paper, the morphology, thermal stability, and crystalline behavior of original and chemically treated sisal fibers were investigated using scanning electron microscopy, thermo gravimetric analysis, and X-ray diffraction techniques.
Abstract: Natural fibers have received vast attention because of their lightweight, combustible, non toxic, low cost, and biodegradable properties. Chemical treatment of natural fibers can clean the fiber surface, stop the moisture absorbance, and increase the surface roughness, which enhance the bond strength between fiber and matrix. In this study, Benzoylation and grafting of sisal fibers were reported using benzoyl chloride of different concentrations and methyl acrylate monomer, respectively. Structure and properties of natural fibers have an obvious effect on the mechanical properties of the biocomposite materials. Therefore, it is thus necessary to know the morphology, thermal stability, and crystalline behavior of original and chemically treated sisal fibers. Morphological changes, thermal stability and crystallinity of fibers were investigated using scanning electron microscopy, thermo gravimetric analysis, and X-ray diffraction techniques. It has been observed that benzoylation and graft copolymerization ...
01 Jan 2011
TL;DR: Sisal fiber is one of the natural fibers widely available in most parts of the world; it requires minimum financial input and maintenance for cultivation and is often grown in wastelands, which helps in soil conservation as mentioned in this paper.
Abstract: The natural resources of the World are depleting very fast due to the high rate of exploitation and low rate of restoration, leading to an increase in global warming and pollution hazards. In recent years, there has been increasing interest in the substitution of synthetic fibers in reinforced plastic composites by natural plant fibers such as jute, coir, flax, hemp, and sisal. Sisal is one of the natural fibers widely available in most parts of the world; it requires minimum financial input and maintenance for cultivation and is often grown in wastelands, which helps in soil conservation. Advantages of sisal fiber are: low density and high specific strength, biodegradable and renewable resource, and it provides thermal and acoustic insulation. Sisal fiber is better than other natural fibers such as jute in many ways, including its higher strength, bright shiny color, large staple length, poor crimp property, variation in properties and quality due to the growing conditions, limited maximum processing temperatures. In recent years, there has been an increasing interest in finding innovative applications for sisal fiber-reinforced composites other than their traditional use in making ropes, mats, carpets, handicrafts, and other fancy articles. Composites made of sisal fibers are green materials and do not consume much energy for their production.
TL;DR: In this paper, a torque rheometer was used to evaluate the rheological properties of sisal fiber (SF)/poly(butylene succinate) (PBS) composites.
TL;DR: In this article, the effects of different conditions of time and temperature, used for the preparation of whiskers from sisal, were investigated to determine the influence of experimental parameters on morphology, crystallinity and thermal stability of materials prepared.
Abstract: In this work, the effects of different conditions of time and temperature, used for the preparation of whiskers from sisal, were investigated to determine the influence of experimental parameters on morphology, crystallinity and thermal stability of materials prepared. The whiskers were obtained after the bleaching of sisal raw fiber with a solution of hydrogen peroxide alkaline. The bleached fiber was submitted to the process of hydrolysis with sulphuric acid solution 60 wt. (%) under three different conditions of temperature and time of extraction: 45 °C and 60 minutes (WS45_60); 45 °C and 75 minutes (WS45_75) and 60 °C and 30 minutes (WS60_30). The whiskers were characterized as the morphology by transmission electron microscopy (MET), crystallinity (DRX), surface charge (zeta potential), sulfur content (by elemental analysis) and thermal stability by thermogravimetry (TGA). The sisal whiskers presented an average length and diameter of 210 nm and 5 nm, respectively. Due to the high agglomeration state of whiskers, differences on dimensional features could not be determined. The results showed a strong dependence on crystallinity of whiskers with temperature and time of extraction. Hydrolysis in higher temperature (60 °C) and lower extraction time (30 minutes) resulted in whiskers with good thermal stability (235 °C), higher crystallinity and preserving the crystalline structure of cellulose.
TL;DR: In this article, the authors evaluate composites produced by the slurry dewatering technique followed by pressing and air curing, reinforced with combinations of polypropylene fibers and sisal kraft pulp at different pulp freeness.
Abstract: Several studies using vegetable fibers as the exclusive reinforcement in fiber-cement composites have shown acceptable mechanical performance at the first ages. However, after the exposure to accelerated aging tests, these composites have shown significant reduction in the toughness or increase in embrittlement. This was mainly attributed to the improved fiber-matrix adhesion and fiber mineralization after aging process. The objective of the present research was to evaluate composites produced by the slurry dewatering technique followed by pressing and air curing, reinforced with combinations of polypropylene fibers and sisal kraft pulp at different pulp freeness. The physical properties, mechanical performance, and microstructural characteristics of the composites were evaluated before and after accelerated and natural aging. Results showed the great contribution of pulp refinement on the improvement of the mechanical strength in the composites. Higher intensities of refinement resulted in higher modulus of rupture for the composites with hybrid reinforcement after accelerated and natural aging. The more compact microstructure was due to the improved packing of the mineral particles with refined sisal pulp. The toughness of the composites after aging was maintained in relation to the composites at 28 days of cure.
TL;DR: Refining the pulp prior to the enzyme treatment resulted in increased grafting which in turn led to handsheets with improved strength-related properties (particularly wet tensile strength) relative to control samples.
TL;DR: Hierarchical porous carbon with ultrahigh surface area (i.e., 3350 m2 g−1) is prepared by utilizing the natural well-defined organization of pores present in sisal fibers as the substrate for constructing hierarchical macro-meso-microporous structure, which allows for rapid molecular diffusion and high pore utilization and thus leads to excellent organic vapour adsorption performance as discussed by the authors.
Abstract: Hierarchical porous carbon with ultrahigh surface area (i.e., 3350 m2 g−1) is prepared by utilizing the natural well-defined organization of pores present in sisal fibers as the substrate for constructing hierarchical macro–meso–microporous structure, which allows for rapid molecular diffusion and high pore utilization and thus leads to excellent organic vapour adsorption performance.
01 Jan 2011
TL;DR: In this article, the optimum mixing of fiber and resin is achieved by using Taguchi method, flexural rigidity and hardness of Sisal and banana (hybrid), Roselle and banana(hybrid) composite at dry and wet conditions were studied.
Abstract: In this research, natural fibers like Sisal (Agave sisalana), Banana (Musa sepientum) & 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. In this paper the optimum mixing of fiber and resin is achieved by using Taguchi method. In this work, flexural rigidity and hardness of Sisal and banana (hybrid), Roselle and banana (hybridand 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.
01 Jul 2011
TL;DR: In this paper, the results of biodegradability tests of natural fibers used by the automotive industry were discussed, namely: coir, coir with latex, and sisal.
Abstract: This paper discusses the results of biodegradability tests of natural fibers used by the automotive industry, namely: coir, coir with latex, and sisal. The biodegradation of coir, coir with latex, and of sisal fibers was determined by monitoring the production of carbon dioxide (CO2) (IBAMA—E.1.1.2, 1988) and fungal growth (DIN 53739, 1984). The contents of total extractives, lignin, holocellulose, ashes, carbon, nitrogen and hydrogen of the fibers under study were determined in order to ascertain their actual content and to understand the results of the biodegradation tests. The production of CO2 indicated low biodegradation, i.e., about 10% in mass, for all the materials after 45 days of testing; in other words, no material inhibited glucose degradation. However, the percentage of sisal fiber degradation was fourfold higher than that of coir with latex in the same period of aging. The fungal growth test showed a higher growth rate on sisal fibers, followed by coir without latex. In the case of coir with latex, we believe the fungal growth was not intense, because natural latex produces a bactericide or fungicide for its preservation during bleeding [1]. An evaluation of the materials after 90 days of aging tests revealed breaking of the fibers, particularly sisal and coir without latex, indicating fungal attack and biodegradation processes.
01 Jan 2011
TL;DR: In this paper, the effect of chalk powder on compressive and impact properties of Sisal/Glass fiber hybrid composites has been studied and it was observed that as the powder quantity increases Compressive and Impact properties are decrease.
Abstract: Natural and synthetic fibres are combined in the same matrix (unsaturated polyester) to make Sisal/Glass fibre hybrid composites and the compressive and impact properties of these hybrid composites were studied. A significant improvement in compressive and impact properties of Sisal/Glass fibre hybrid composites has been found. The Chalk powder (additive) is also added to the resin (unsaturated polyester) in proportions of 1%, 2%, 3% by weight of resin respectively and Sisal/Glass fibre hybrid composites were prepared by using this resin to study the effect of Chalk powder on compressive and Impact properties of these hybrid composites. It is also observed that as the Chalk powder quantity increases Compressive and impact properties are decrease.
TL;DR: Sisal paper has been introduced as a new reinforcement form in natural fibre based polymer composites as discussed by the authors, which can replace 84.5% of glass fibre in a moderate glass reinforcing epoxy composite to obtain an equivalent range of tensile modulus.
Abstract: Sisal paper has been introduced as a new reinforcement form in natural fibre based polymer composites. Sisal fibre obtained from Agava sisalana was transformed to pulp with moderate beating to retain sufficient reinforcing strength in split fibres, and then was converted to handmade paper form. The paper so obtained was impregnated with epoxy resin, stacked one over the other and subjected to heat and pressure to make layered composites. Chopped Strand Mat (CSM) of glass fibre was introduced in the composite to make high strength sisal–glass–epoxy composites. Sisal paper epoxy composites achieved 32.5 MPa tensile strength at 23.7 vol% of sisal paper that was further enhanced to 71.2 MPa by adding 14 vol% of glass CSM in the hybrid composite. The mechanical properties of hybrid layered sisal–glass–epoxy revealed that sisal paper can replace 84.5% of glass fibre in a moderate glass reinforcing epoxy composite to obtain an equivalent range of tensile modulus.
TL;DR: In this paper, sisal fibers were subjected to various chemical and physical modifications such as mercerization, heating at 100°C, permanganate treatment, benzoylation, and silanization.
Abstract: To improve the fiber/matrix interaction, sisal fibers were subjected to various chemical and physical modifications such as mercerization, heating at 100°C, permanganate treatment, benzoylation, and silanization. Polyester composites were fabricated using compression molding. Tensile and flexural properties increased for every treated fiber-reinforced composites with a reduction in the impact strength. This is attributed to the improved interfacial adhesion between fiber and polyester matrix. An increase in thermal stability was observed for the treated fiber-reinforced composites especially at lower temperature. Significant reduction in water uptake occurred for the treated fiber-reinforced composites at 30°C and 90°C. Scanning electron micrograph studies have been used to substantiate the above observations. POLYM. COMPOS., 32:131-138, 2011. © 2010 Society of Plastics Engineers.
TL;DR: In this paper, a dewaxed sisal fiber-reinforced epoxy composite (DSFREC) is compared to the raw sisal-fiber reinforced epoxy composites (RSFREC), and the structural parameters of the fiber are correlated with the mechanical and electrical properties of the composite.
Abstract: Chemical modification of the sisal fiber is done through dewaxing. Increment in the degree of crystallinity, crystallite size, and bulk density are observed in case of the dewaxed sisal fiber. The partial removal of wax, hemicellulose, and lignin content is confirmed from the FTIR spectra. Better flexural strength and tensile strength are observed in case of dewaxed sisal fiber-reinforced epoxy composite (DSFREC) in comparison to the raw sisal fiber-reinforced epoxy composite (RSFREC). This may be due to the improvement in the adhesion between the fiber and matrix. Lower values of dielectric constant (er) and dielectric loss (tanδ) are also observed in case of DSFREC. The shifting of M″max toward higher frequency side with rise in temperature ascribing a correlation between motions of mobile ions and suggests a spread of relaxation times. Moreover, the structural parameters of the fiber are correlated with the mechanical and electrical properties of the composite.