Showing papers on "SISAL published in 2010"
TL;DR: In this article, the tensile, flexural and dielectric properties of vakka fiber composite are investigated for electrical insulation applications and it has been observed that tensile properties increase with respect to volume fraction of fiber.
296 citations
TL;DR: Sisal fiber-cement composites reinforced with long unidirectional aligned fibers were developed and their physical-mechanical behavior was characterized in this article, where flat and corrugated sheets were cast by a manual lay-out of the fibers in a selfcompacted cement matrix and compressed with a pressure of 3MPa.
284 citations
TL;DR: In this article, the performance of glass/sisal hybrid composites focusing on mechanical (flexural and impact) and dynamic mechanical analyses (DMTA) was evaluated with different fiber loadings and different volume ratios between glass and sisal.
Abstract: This work aims to evaluate the performance of glass/sisal hybrid composites focusing on mechanical (flexural and impact) and dynamic mechanical analyses (DMTA). Hybrid composites with different fiber loadings and different volume ratios between glass and sisal were studied. The effect of the fiber length has also been investi- gated. The densities of the composites were compared with the theoretical values, showing agreement with the rule of mixtures. The results obtained in the flexural and impact analysis revealed that, in general, the properties were always higher for higher overall reinforcement content. By DMTA, an increase in the storage and loss modulus was found, as well as a shift to higher values for higher glass loading and overall fiber volume. It was also noticed an increase in the efficiency of the filler and the calculated acti- vation energy for the relaxation process in the glass transi- tion region. The fiber length did not significantly change the results observed in all analyses carried out in this work. The calculated adhesion factor increased for higher glass loadings, meaning the equation may not be applied for the system studied and there are other factors, besides adhe- sion influencing energy dissipation of the composites. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 887-896, 2010
227 citations
TL;DR: In this paper, sisal fibers were mercerized, under tension and no tension, to improve their tensile properties and interfacial adhesion with soy protein resins, which is known to minimize fiber shrinkage and to lower the microfibrillar angle by aligning them along the fiber axis.
Abstract: Sisal fibers were mercerized, under tension and no tension, to improve their tensile properties and interfacial adhesion with soy protein resin. Mercerization of fibers under tension is known to minimize fiber shrinkage and to lower the microfibrillar angle by aligning them along the fiber axis. Mercerization improved the fracture stress and Young’s modulus of the sisal fibers while their fracture strain and toughness decreased. Mercerized sisal fiber-reinforced composites with soy protein resin showed improvement in both fracture stress and stiffness by 12.2% and 36.2%, respectively, compared to the unmercerized fiber-reinforced composites. Scanning electron microscope (SEM) photomicrographs of the composite fracture surfaces showed shorter fibrils protruding in the mercerized fiber-reinforced composites resulting in better sisal fiber/soy adhesion. Changed fiber surface properties were also responsible for better adhesion.
206 citations
TL;DR: In this paper, the composition, morphology and properties of the four natural fibers were examined in order to select an appropriate fiber for manufacture of woven limited life geotextiles (LLGs).
199 citations
TL;DR: In this paper, a rubber seed oil-based polyurethane composite reinforced with unidirectional sisal fibers was prepared and characterized, and the properties of the composite gave good thermal and mechanical properties.
166 citations
TL;DR: In this paper, short randomly oriented banana and sisal hybrid fiber reinforced polyester composites, banana/polyester composite, and polyester/sisal composite were fabricated at different fiber loading, such as 0.20 to 0.40 Vf.
Abstract: Short randomly oriented banana and sisal hybrid fiber reinforced polyester composites, banana/polyester composites and sisal/polyester composites were fabricated at different fiber loading say, 0.20 to 0.50 Vf. Composites were prepared by varying the relative volume fraction of the two fibers at each fiber loading. When the fiber loading was increased; tensile, flexural, and impact properties increased. Better performance was shown by composites having volume fraction, 0.40 Vf. Tensile strength, tensile modulus, flexural strength, and flexural modulus showed a positive hybrid effect when the volume ratio of the fiber was varied in the hybrid composites at each fiber loading. Maximum tensile strength was observed in composites having volume ratio of banana and sisal 3:1. When the volume ratio of sisal was increased, the impact strength of the composite increased. Different layering patterns were tried at 0.40 Vf, keeping the volume ratio of fibers 1:1. Tensile properties were slightly greater in the trilay...
160 citations
TL;DR: In this article, composites of post-consumer high-density polyethylene (HDPE) reinforced with sisal fibers were prepared by extrusion of modified and unmodified materials containing either 5 or 10% fibers.
Abstract: Natural fibers are widely used as plastic composite material reinforcements. In this work, composites of post- consumer high-density polyethylene (HDPE) reinforced with sisal fibers were prepared. PE and sisal fibers were chemi- cally modified to improve their compatibilities, try to increase the hydrophobic character of the sisal fiber and hydrophilic character HDPE. Sisal was mercerized with a NaOH solution and acetylated and the PE was oxidized with KMnO4 solu- tion. The chemically modified fibers were characterized by Fourier Transformed Infrared Spectroscopy (FTIR) and 13 C Nuclear Magnetic Resonance Spectroscopy ( 13 C NMR). The composites were prepared by extrusion of modified and unmodified materials containing either 5 or 10 wt% fibers. The morphology of the obtained materials was evaluated by SEM. The fiber chemical modification improves it adhesion with matrix, but not benefit were obtained with HDPE oxida- tion. Flexural and impact tests demonstrated that the composites prepared with modified sisal fibers and unmodified PE present improved mechanical performance compared to pure PE.
132 citations
TL;DR: This study shows that biobased composites with good properties can be prepared using a high proportion of materials obtained from natural resources using glyoxal, which is a dialdehyde obtained from several natural resources.
127 citations
TL;DR: In this paper, the effect of NaOH treatment of sisal fibres on the tensile, flexural and chemical resistance properties of these sisal/carbon hybrid composites has also been studied.
Abstract: The variation of mechanical properties such as tensile and flexural properties of randomly oriented unsaturated polyester based sisal/carbon fibre reinforced hybrid composites with different fibre weight ratios have been studied. The chemical resistance test of these hybrid composites to various solvents, acids and alkalies were studied. The effect of NaOH treatment of sisal fibres on the tensile, flexural and chemical resistance properties of these sisal/carbon hybrid composites has also been studied. The hybrid composites showed an increase in tensile and flexural properties with increase in the carbon fibre loading. The tensile properties and flexural properties of these hybrid composites have been found to be higher than that of the matrix. Significant improvement in tensile properties and flexural properties of the sisal/carbon hybrid composites has been observed by alkali treatment. The chemical resistance test results showed that these untreated and alkali treated hybrid composites are resistance to all chemicals except carbon tetra chloride. Hand lay-up technique was used for making the composites and tests are carried out by using ASTM methods.
127 citations
TL;DR: In this paper, the epoxy-based hybrid composites were developed by combining the sisal and glass fibers into epoxy matrix, and the aforementioned properties were optimally improved at 2 cm fiber length when compared with 1 and 3 cm fiber lengths.
Abstract: In this article, the epoxy-based hybrid composites were developed by combining the sisal and glass fibers into epoxy matrix. Hardness, impact strength, frictional coefficient, and chemical resistance of hybrid composites with and without alkali treatments were studied. Variation of the aforementioned mechanical proper- ties and chemical resistance was studied with different fiber lengths such as 1, 2, and 3 cm. A 9 vol.% of the sisal and glass fibers was reinforced into the epoxy matrix. The aforementioned mechanical properties were optimally improved at 2-cm fiber length when compared with 1 and 3 cm fiber lengths. Chemical resistance was also significantly improved for all chemicals except sodium carbonates and toluene.
TL;DR: In this article, the mechanical properties of pure sisal, pure glass, and hybrid sisal/glass compression-molded composites, in which various stacking sequences of fiber mat layers were used, were investigated.
Abstract: This study focused on the mechanical properties of pure sisal, pure glass, and hybrid sisal/glass compression-molded composites, in which various stacking sequences of fiber mat layers were used. It is shown that hybridization originated a material with general intermediate properties between pure glass and pure sisal. However, the importance of controlling the stacking sequence to enhance properties was evident. For instance, to optimize flexural behavior, there must be glass fibers mainly on the top and bottom surfaces. Furthermore, depending on the type of loading and stacking sequence, some hybrid composites may show properties very close to those of pure glass.
TL;DR: The present work shows for the first time the use of analytical pyrolysis as an effective approach to study fibre functionalization by laccase-induced grafting of phenols.
TL;DR: In this paper, a sisal/glass reinforced polypropylene (PP) hybrid composites with short sisal and glass fibers were prepared using twin-screw extruder, followed by injection molding in the presence and absence of maleic anhydride grafted PP (MAPP) as a coupling agent.
Abstract: Hybrid composites of polypropylene (PP) reinforced with short sisal and glass fibers were prepared using twin-screw extruder, followed by injection molding in the presence and absence of maleic anhydride grafted PP (MAPP) as a coupling agent. The mechanical properties such as tensile strength, flexural strength, and impact strength increased by an optimum value at 15% sisal and 15% glass fiber loading in the presence of 2% MAPP. The rate of water absorption in the composites decreased due to the presence of glass fiber and coupling agent. The storage modulus of sisal/glass reinforced PP hybrid composites (SGRP) showed maximum improvement after treatment with MAPP. The fiber matrix morphology of the interface region in the composites was examined using scanning electron microscopy. The differential scanning calorimetry thermogram confirms higher thermal stability in the case of hybrid composites.
TL;DR: In this article, the morphology of composite electrolytes was investigated by scanning electron microscopy and their thermal behavior (characteristic temperatures, degradation temperature) were investigated by thermogravimetric analysis and differential scanning calorimetry.
TL;DR: In this article, the effect of chemical treatment on the constituents and tensile properties of sisal fiber (Agave Sisalana) was investigated and the results showed that the chemical treatments enhance the removal of lignin and hemicelluloses which are detrimental to the bonding strength of composite produced from natural fibres except that of sample treated with alkaline peroxide.
Abstract: This work was carried out to investigate the effect of chemical treatment on the constituents and tensile properties of sisal fibre (Agave Sisalana). Sisal leaves were cut and buried underground close to the stream and were wetted with water regularly in order to ensure proper fermentation for about 15 days. The fermented leaves were washed and sun dried. The dried sisal fibre obtained was treated mechanically with chemicals after which the percentages of their constituents were characterized and, their tensile properties determined with Instron universal tensile testing machine. The results show that the chemical treatments enhance the removal of lignin and hemicelluloses which are detrimental to the bonding strength of composite produced from natural fibres except that of sample treated with alkaline peroxide. The results of the tensile test revealed that sample treated sequentially with KOH, acetic acid, NaCl and HCl has the best tensile properties followed by the sample treated with alkaline peroxide.
15 Jan 2010-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the experimental behavior of sisal fiber reinforced cement composites subjected to high speed tension load was studied by using a high rate servo-hydraulic testing machine.
Abstract: The experimental behavior of sisal fiber reinforced cement composites subjected to high speed tension load was studied. High strain rates were achieved by using a high rate servo-hydraulic testing machine. A state-of-the-art high speed Phantom camera was also used to take images from the specimen during the test. The images were used in a digital image correlation model to determine the displacement fields and to calculate crack spacing. The effect of strain rate was investigated by comparing static and dynamic tensile tests which were performed at strain rates ranging from 5.5 × 10−6 to 24.6 s−1, respectively. A numerical tension stiffening model based on nonlinear finite difference method was used to simulate tensile cracking behavior of sisal fiber cementitious composites. The composite presented strain rate sensitivity for ultimate tensile strength and strain capacity with a dynamic amplification factor of 1.26.
TL;DR: In this article, the influence of enzyme (laccase) and alkali treatments on the surface lignin of single cellulose fiber was investigated, which greatly affected the surface physical and chemical properties.
Abstract: This paper is an attempt to investigate the influences of enzyme (laccase) and alkali treatments on the surface lignin of single cellulose fibre. The fibre surface characteristics and the interfacial behaviour of the sisal fibre/phenolic resin composites were also studied by SEM, AFM, XPS. The surface lignin greatly affected the surface physical and chemical properties of single cellulose fibres. The surface lignin concentration was up to 35% for the raw fibre without any treatment, and then it decreased to 24%, 20% and 18% for the fibres with laccase treatment, alkali treatment and laccase/alkali treatment, respectively. The removal of lignin from fibre surface could enhance the interfacial strength of composites, and thus increase the tensile strength and internal bonding strength by 43% and 51%, respectively, for the composites obtained from laccase/alkali treated fibres.
TL;DR: The study demonstrates that sugarcane bagasse lignin obtained from a bioethanol plant can be used without excessive purification in the preparation of lignocellulosic fiber‐reinforced biobased composites displaying high mechanical properties.
Abstract: In the present study, the main focus was the characterization and application of the by-product lignin isolated through an industrial organosolv acid hydrolysis process from sugarcane bagasse, aiming at the production of bioethanol. The sugarcane lignin was characterized and used to prepare phenolic-type resins. The analysis confirmed that the industrial sugarcane lignin is of HGS type, with a high proportion of the less substituted aromatic ring p-hydroxyphenyl units, which favors further reaction with formaldehyde. The lignin―formaldehyde resins were used to produce biobased composites reinforced with different proportions of randomly distributed sisal fibers. The presence of lignin moieties in both the fiber and matrix increases their mutual affinity, as confirmed by SEM images, which showed good adhesion at the biocomposite fiber/matrix interface. This in turn allowed good load transference from the matrix to the fiber, leading to biobased composites with good impact strength (near 500 J m ―1 for a 40 wt% sisal fiber-reinforced composite). The study demonstrates that sugarcane bagasse lignin obtained from a bioethanol plant can be used without excessive purification in the preparation of lignocellulosic fiber-reinforced biobased composites displaying high mechanical properties.
TL;DR: In this paper, the effects of material optimization and compounding processes on the properties of natural fiber composites were studied and the thermal stabilities of sisal fiber and jute fiber were compared by thermogravimetric analysis.
Abstract: In this study, the effects of material optimization and compounding processes on the properties of natural fiber composites were studied. The thermal stabilities of sisal fiber and jute fiber were compared by thermogravimetric analysis. The influences of fiber content, coupling agent, fiber geometry, and fiber distribution on the properties were also researched. It was observed that sisal fiber had more thermal stability than jute fiber. Addition of coupling agent, long fiber length, and uniform fiber distribution led to higher performance composites. For the sisal fiber-reinforced polypropylene composites, the critical fiber length was 2.27 mm and the interfacial shear strength was 22.03 MPa with MAPP. The tensile strength of composites was also theoretically predicted based on Kelly—Tyson model.
TL;DR: In this paper, a composite reinforced with sisal fibers pre-impregnated with hydroxyl-terminated polybutadiene rubber (HTPB) was used as both impact modifier and coupling agent.
TL;DR: In this paper, a statistical evaluation based on the Weibull method was performed to correlate the mechanical properties and the diameter of different lignocellulosic fibers, and the sisal, rami and curaua fibers were found to have a hyperbolic correlation between their ultimate strength and diameter.
Abstract: A statistical evaluation based on the Weibull method was performed to correlate the mechanical properties and the diameter of different lignocellulosic fibers. The sisal, rami and curaua fibers were found to have a hyperbolic correlation between their ultimate strength and diameter. This permitted to select thinner high strength fibers, with over 1000 MPa, as reinforcement for the strongest polymer composites ever fabricated with these fibers. A structural analysis was conducted by electron microscopy to identify the strengthening mechanism for both, the high performance fiber and their improved polymer composites.
TL;DR: In this article, the chemical resistance of the treated and untreated silk/sisal hybrid composites to various acids, alkalis, and solvents was studied, in order to find out whether these composites can be used for manufacturing products that are resistant to chemicals.
Abstract: The natural fiber environmental friendly composites of untreated and alkali treated silk-sisal unsaturated polyester-based hybrid composites were prepared by using hand lay-up technique. The fiber length was taken as 2 cm and the sisal fibers were treated with 2% NaOH. The chemical resistance of the treated and untreated silk/sisal hybrid composites to various acids, alkalis, and solvents was studied. The chemical resistance tests of these hybrid composites were performed in order to find out whether these composites can be used for manufacturing products that are resistant to chemicals.
TL;DR: In this article, the authors investigated the frequency and temperature dependence of dielectric constant (er), ac conductivity (σac), and complex impedance spectroscopy studies on cured polyester matrix and sisal fiber-reinforced polyester composites (SFRPC).
Abstract: Frequency and temperature dependence of dielectric constant (er), dielectric loss (tanδ), ac conductivity (σac) and complex impedance spectroscopy studies on cured polyester matrix and sisal fibre-reinforced polyester composites (SFRPC) have been investigated in the frequency range from 180 Hz to 1 MHz and temperature range from room temperature to 200 °C. The experimental results showed that with the incorporation of sisal fibre, the values of er, tanδ and σac are increased. It is also found that the values of er and tanδ for both cured polyester matrix and SFRPC are decreased with increasing frequency, which indicates that the major contribution to the polarization may come from orientation polarization and interfacial polarization. The increasing value of er with increasing temperature at a particular frequency is due to free motion of the dipole molecular chains within the cured polyester matrix and SFRPC at higher temperature.
TL;DR: In this article, a systematic experimental investigation on the mechanical performance of sisal fibers was performed and Young's modulus was determined and the failure mechanisms were described and discussed in terms of the fiber microstructure as well as the defect population in the fibers.
Abstract: Natural fibers are gaining a significant amount of attention as reinforcement in composite materials. In this work we present a systematic experimental investigation on the mechanical performance of sisal fibers. Tensile tests were performed and Young’s modulus determined. Weibull statistics were used to quantify the degree of variability in fiber strength, at the different gage lengths. The Weibull modulus decreased from 4.6 to 3.0 as the gage length increased from 10 mm to 40 mm, respectively. Fatigue tensile tests were performed at stress-levels ranging between 80 to 400 MPa. The sisal fibers did not exhibit fatigue below a maximum fatigue level of 320 MPa. SEM was used to investigate the failure mode of the fibers. The failure mechanisms will be described and discussed in terms of the fiber microstructure as well as the defect population in the fibers.
TL;DR: In this article, an investigation of the major sugar composition of sisal leaf waste liquids was described, where the fractionation of an ethanol extract from the liquid residue of Agave sisalana by open chromatography column packed with SiO 2 resulted in the isolation of d -mannitol.
TL;DR: In this paper, the effects of reinforcement geometry and alkaline treatment of fibers were evaluated for biomass composites, and the effect of these properties on thermogravimetric and differential scanning calorimetry techniques was shown.
Abstract: This work reports hygroscopic, thermal, and mechanical properties of biomass composites comprising sisal fiber reinforcing castor oil PU resin. The effects of reinforcement geometry and alkaline treatment of fibers were evaluated. In general, alkaline treatment improved quasi-static tensile properties of composites with short randomly oriented and long aligned sisal fibers, respectively. On the other hand, an adverse effect of alkaline treatment was observed in the mechanical behavior of the composite with bidirectional fabric architecture. The outstanding influence of moisture on thermo-mechanical properties of biomass composites was confirmed through thermogravimetric and differential scanning calorimetry techniques. Dynamical-mechanical thermal analysis showed increased storage modulus (i.e., stiffness) and decreased damping properties of biomass composites as compared to neat PU matrix. Dynamical-mechanical testing also detected unexpected decrease on glass transition temperature of composites in rega...
TL;DR: In this paper, a light scattering study of solutions of sisal, M-sisal, microcrystalline and cotton celluloses in LiCl/DMAc has shown that they are present as aggregates, with (an apparent) average aggregation numbers of 5.2, 3.8, and 35.3, respectively.
Abstract: We report here on some aspects of the acetylation in LiCl/N,N-dimethylacetamide, DMAc, of untreated and mercerized sisal cellulose, hereafter designated as sisal and M-sisal, respectively. Fiber mercerization by NaOH solution has resulted in the following changes: 29.9% decrease in the index of crystallinity; 16.2% decrease in the degree of polymerization and 9.3% increase in α-cellulose content. A light scattering study of solutions of sisal, M-sisal, microcrystalline and cotton celluloses in LiCl/DMAc has shown that they are present as aggregates, with (an apparent) average aggregation numbers of 5.2, 3.2, 9.8, and 35.3, respectively. The presence of these aggregates affects the accessibility of cellulose during its functionalization. A study of the evolution of the degree of substitution, DS, of cellulose acetate as a function of reaction time showed an increase up to 5 h, followed by a decrease at 7 h. Possible reasons for this decrease are discussed. As expected, M-sisal gave a higher DS that its untreated counterpart.
Journal Article•
TL;DR: In this paper, an investigation of the influence of chlorine dioxide treatment on the surface lignin of sisal fibres has been carried out, and the results indicate that the surface properties of single sisal fiber can be tailored to improve the fiber/resin interface.
Abstract: This paper describes an investigation of the influences of chlorine dioxide treatment on fibre surface lignin. The fibre surface characteristics and the interfacial behaviour of the sisal fibre/phenolic resin composites were also studied by SEM, AFM, and XPS. The results show that the surface of the untreated fibre contains a large amount of lignin with granular structure and non-granular structure. The surface lignin concentration is up to 51% for the untreated fibre, and then it decreases to 24% and 20% for fibres treated with 1.5 % and 2.0% chlorine dioxide, respectively. The removal of lignin from the fibre surface can enhance the interfacial strength of the composites, giving rise to increases by 36% and 28% in tensile strength and internal bonding strength. These results indicate that the surface properties of single sisal fibres can be tailored to improve the fibre/resin interface. Chlorine dioxide treatment has potential for surface modification of sisal fibre in engineering the interfacial behaviour of composites.
TL;DR: In this article, the treatment of the sisal fibers with acetylation was applied at different temperatures and reaction times, and the efficiency of treatments, considering the reduction of the hydrophilicity and maintenance of the mechanical properties, was evaluated by water sorption, mechanical properties and the infrared spectroscopy.
Abstract: The use of vegetable fibers in composites is highly viable regarding about the use of materials from renewable sources, the biodegradability and the socioeconomic advantages in the production of raw vegetable. The sisal fibers are highly hygroscopic and this is a main problem in the production of composites, inducing dimensional changes under moisture influence, deposition of the matrix products and degradation. The treatment of the acetylation was applied at different temperatures and reaction times, and the efficiency of treatments, considering the reduction of the hydrophilicity and maintenance of the mechanical properties, was evaluated by water sorption, mechanical properties and the infrared spectroscopy. With acetylation the fibers had weight reductions for water sorption up to 50% compared to untreated. The treatments for 3 h decreased the mechanical properties while the 120 °C for 1 h showed better physico-mechanical properties and increase of apolar groups.