Showing papers on "Natural fiber published in 2010"
TL;DR: In this paper, the authors review the recent progress in using silane coupling agents for NFPCs, summarizes the effective silane structures from the silane family, clarifies the interaction mechanisms between natural fibers and polymer matrices, and presents the effects of silane treatments on the mechanical and outdoor performance of the resulting composites.
Abstract: Natural fiber reinforced polymer composites (NFPCs) provide the customers with more alternatives in the material market due to their unique advantages. Poor fiber–matrix interfacial adhesion may, however, negatively affect the physical and mechanical properties of the resulting composites due to the surface incompatibility between hydrophilic natural fibers and non-polar polymers (thermoplastics and thermosets). A variety of silanes (mostly trialkoxysilanes) have been applied as coupling agents in the NFPCs to promote interfacial adhesion and improve the properties of composites. This paper reviews the recent progress in using silane coupling agents for NFPCs, summarizes the effective silane structures from the silane family, clarifies the interaction mechanisms between natural fibers and polymer matrices, and presents the effects of silane treatments on the mechanical and outdoor performance of the resulting composites.
1,725 citations
TL;DR: In this article, a hybrid of kenaf/glass fiber was used to enhance the desired mechanical properties for car bumper beams as automotive structural components with modified sheet molding compound (SMC).
332 citations
TL;DR: In this paper, the effect of these treatments on the structure, composition and properties of fibers was studied using SEM, FTIR, XPS, TGA and other analyses, showing that treatment with H2O2 is the most efficient in terms of waxy and fatty acid residues removal but it does not modify the surface chemical composition.
305 citations
TL;DR: In this article, the authors compared the performances of polylactic acid (PLA)/kenaf (PLA-K) and PLA/rice husk composites in terms of biodegradability, mechanical and thermal properties.
Abstract: This paper investigates and compares the performances of polylactic acid (PLA)/kenaf (PLA-K) and PLA/rice husk (PLA-RH) composites in terms of biodegradability, mechanical and thermal properties. Composites with natural fiber weight content of 20% with fiber sizes of less than 100 μm were produced for testing and characterization. A twin-screw extrusion was used to compound PLA and natural fibers, and extruded composites were injection molded to test samples. Flexural and Izod impact test, TGA, soil burial test and SEM were used to investigate properties. All results were compared to a pure PLA matrix sample. The flexural modulus of the PLA increased with the addition of natural fibers, while the flexural strength decreased. The highest impact strength (34 J m−1), flexural modulus (4.5 GPa) and flexural strength (90 MPa) were obtained for the composite made of PLA/kenaf (PLA-K), which means kenaf natural fibers are potential to be used as an alternative filler to enhance mechanical properties. On the other hand PLA-RH composite exhibits lower mechanical properties. The impact strength of PLA has decreased when filled with natural fibers; this decrease is more pronounced in the PLA-RH composite. In terms of thermal stability it has been found that the addition of natural fibers decreased the thermal stability of virgin PLA and the decrement was more prominent in the PLA-RH composite. Biodegradability of the composites slightly increased and reached 1.2 and 0.8% for PLA-K and PLA-RH respectively for a period of 90 days. SEM micrographs showed poor interfacial between the polymer matrix and natural fibers.
255 citations
TL;DR: In this article, the potential of grain by-product such as barley husk, coconut shell as reinforcements for thermoplastic as an alternative or together with wood fibres was investigated, where the particle morphology and particle size was investigated by scanning electron microscopy.
245 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 article, the effects of modification of abaca fiber were assessed on the basis of morphology and thermal resistance and as well as on mechanical, thermal and environmental stress corrosion resistance properties of the resulting composites.
175 citations
TL;DR: In this paper, the authors report the work on oil palm empty fruit bunch (OPEFB) fiber-reinforced polymer composites with some interest on the OPEFB physical structure, and chemical compositions.
Abstract: Natural fiber-reinforced polymer composite materials have emerged in a wide spectrum of area of the polymer science. The composite produced from these types of materials are low density, low cost, comparable specific properties, and most importantly they are environmental friendly. The composite materials produced from oil palm fibers and commercially available polymers have offered some specific properties that can be comparable to conventional synthetic fiber composite materials. However, these properties are greatly dependent on the compatibility of oil palm fibers and matrix phase with moisture absorption as one of the critical issues that becomes the drawbacks of the oil palm fiber polymer composite materials. Apparently, it greatly affects the physical as well as mechanical properties of the composite materials. The present review reports the work on oil palm empty fruit bunch (OPEFB) fiber-reinforced polymer composites with some interest on the OPEFB physical structure, and chemical compositions. Finally, the incorporation of OPEFB into polymeric materials leads to several interesting consequences on the water absorption characteristics and the mechanical properties, which have been reviewed.
168 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 paper, three types of nonwovens were developed using needle-punching technique by blending bamboo, banana, and jute fibers with polypropylene staple fibers in the ratio of 50 : 50.
Abstract: As natural fibers are noise-absorbing materials, renewable and biodegradable nonwovens have been developed using natural fibers such as banana, bamboo, and jute fibers for the automotive interiors to reduce noise, which currently contain traditional materials such as glass and other manufactured fibers and foams that are difficult to recycle. Three types of nonwovens were developed using needle-punching technique by blending bamboo, banana, and jute fibers with polypropylene staple fibers in the ratio of 50 : 50. Sound absorption coefficient was tested by impedance tube method (ASTM E 1050). Comparison of physical properties such as areal density, thickness, stiffness, tensile strength, elongation, structural properties, and comfort properties such as air permeability and thermal conductivity were performed for all samples. It is observed that the bamboo/polypropylene nonwoven with its compact structure showed, higher tensile strength, higher stiffness, lower elongation, lower thermal conductivity, lower ...
154 citations
TL;DR: In this paper, flame-retarded Ramie fiber-reinforced poly(lactic acid) (PLA) composites were prepared using three processes: (1) PLA was blended with ammonium polyphosphate (APP), and then the resulting flame-rearded PLA was combined with ramie fibers; (2) Ramie fibers underwent flame-resistant treatment with APP, which were then compounded with PLA; and (3) PLA and ramie, both had been flame-resarded using APP, were blended together.
Abstract: Fully degradable natural fiber/degradable polymer composites have received much research attention and have various applications such as in automotive components. But flammability limits their application; it is important to improve the flame retardancy of fully degradable composites with environmentally friendly flame retardants. Flame-retarded ramie fiber-reinforced poly(lactic acid) (PLA) composites were prepared using three processes: (1) PLA was blended with ammonium polyphosphate (APP), and then the resulting flame-retarded PLA was combined with ramie fibers; (2) ramie fibers underwent flame-retardant treatment with APP, which were then compounded with PLA; and (3) PLA and ramie, both of which had been flame-retarded using APP, were blended together. The APP in the composites is shown to be very effective in improving flame retardancy according UL94 test and limiting oxygen index measurements. Thermogravimetric analysis shows that the improved flame retardancy is due to increased char residue at high temperature. The loading of APP disturbs the compatibility between PLA and fibers, which can be directly observed using scanning electron microscopy. Furthermore it has an influence on the dynamic mechanical properties and mechanical properties according dynamic mechanical analysis and mechanical measurements. The results show that composites produced using the third process not only have the best flame retardancy but also comparatively better mechanical properties. Copyright © 2009 Society of Chemical Industry
TL;DR: In this article, the potential use of natural fibers in composite materials, their availability, processing features, mechanical and physical properties, and some of their applications in India are discussed, focusing on the potential application of natural fiber in composite composite materials.
Abstract: This study focuses on the potential use of natural fibers in composite materials, their availability, processing features, mechanical and physical properties, and some of their applications in India.
TL;DR: In this paper, the changes of tensile strength, water absorption, and thermal properties of composites after chemical treatments to wood fibers and mineral fillers were measured, and the results showed that wood fiber addition and talc addition had little effect on water absorption.
Abstract: Hybrid filler reinforced composites are considered as a high performance materials, but limited numbers of researches on hybridizations of wood fibers and mineral fillers were reported. Generally, high amount of filler content in composites can lead to the reduction of interfacial adhesion between matrix polymer and fillers, and it limits their applications. In this study, we measured the changes of tensile strength, water absorption, and thermal properties of composites after chemical treatments to wood fibers and mineral fillers. Coupling agent had its own optimum amount for wood fibers and talc to obtain the highest tensile strength. Talc addition showed little effect of the tensile strength with alkali treated wood fibers. Talc addition and silane treatment showed opposite effects on water absorption. Melting enthalpy was decreased by addition of the fillers because of the reduced amount of the crystallizable resin and because of the interference of the fillers for crystallization process.
TL;DR: In this paper, the influence of the cellulose fiber concentration on the structural, thermal, mechanical, and morphological properties of rigid polyurethane composite foams was investigated. But, the cellulosic fibrous industrial residue was rationally valorized as a filler, which yielded materials with mechanical resistance and a susceptibility to fungi in a wet environment.
Abstract: Rigid polyurethane composite foams were prepared with cellulose fibers as a filler. The cellulose fibers were an industrial residue of blanched cellulose pulp production. The influence of the cellulose fiber concentration on the structural, thermal, mechanical, and morphological properties of the foams was investigated. We also studied the influence of the cellulose fibers on the foam's resistance to fungal attack by placing a suspension of known fungus in contact with the surface of the foam and following the morphological evolution as a function of time (for 60 days). The increase in the cellulose filler concentration in the foams, up to 16% w/w with respect to the polyol, changed their properties as follows: (1) the cell size decreased, (2) the thermooxidative stability and mechanical properties remained approximately constant, (3) the thermal conductivity decreased slightly, and (4) fungal growth was observed. Therefore, a cellulosic fibrous industrial residue was rationally valorized as a filler in classical rigid polyurethane foams; this yielded materials with mechanical resistance and a susceptibility to fungi in a wet environment. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
07 Mar 2010
TL;DR: In this paper, the use of Kenaf, Hibiscus cannabinus, as a possible glass replacement in fiber reinforced composites has been investigated, and preliminary results show that it has similar properties to glass fiber.
Abstract: The need for renewable fiber reinforced composites has never been as prevalent as it currently is. Natural fibers offer both cost savings and a reduction in density when compared to glass fibers. Though the strength of natural fibers is not as great as glass, the specific properties are comparable. Currently natural fiber composites have two issues that need to be addressed: resin compatibility and water absorption. The following preliminary research has investigated the use of Kenaf, Hibiscus cannabinus , as a possible glass replacement in fiber reinforced composites. Introduction Research on natural fiber composites has existed since the early 1900’s but has not received much attention until late in the 1980’s. Composites, primarily glass but including natural reinforced composites, are found in countless consumer products including: boats, skis, agricultural machinery and cars 1,2,3 . A major goal of natural fiber composites is to alleviate the need to use expensive glass fiber ($3.25/kg) which has a relatively high density (2.5 g/cm³) and is dependent on nonrenewable sources
TL;DR: In this paper, the surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM) and the composites showed accelerated biodegradation with 20-25% loss in weight after 50-60 days.
Abstract: Woven and nonwoven flax fiber reinforced poly lactic acid (PLA) biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM). Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20-25% loss in weight after 50-60 days. On the other hand, in presence of dicumyl peroxide (as additive), biodegradation of the composites was relatively slow as confirmed by only 5-10% loss in weight even after 80-90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add differ- ent amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.
TL;DR: In this article, the properties of kenaf/phenol-formaldehyde (PF), fiberfrax/PF, and hybrid PF composites have been investigated as a function of fiber loading.
Abstract: In this study, mechanical properties such as tensile characteristics, flexural characteristics, impact strengths, and hardness of kenaf/phenol-formaldehyde (PF), fiberfrax/PF, and kenaf/fiberfrax hybrid PF composites have been investigated as a function of fiber loading. Composite samples were prepared by mixing the fibers and resin in a mixing chamber for 5 min. The composite sheets were prepared by pressing fiber-resin material in a steel mold at 120°C for 30 min at 10 MPa pressure. The test samples were cut from the composite sheets. At least five specimens were tested and mean value was taken for each composite according to ASTM standards. The reinforcing effects of kenaf and fiberfrax fibers were evaluated at various fiber loadings, that is, 19, 28, 36, 43, 52, and 62 vol. %. The hybrid effect of kenaf and fiberfrax fiber on the tensile, flexural, impact strengths, and hardness was also investigated for various ratios of kenaf/fiberfrax fiber loadings ranging between 1 : 0 and 0 : 1. Total fiber load...
TL;DR: In this paper, the effects of species, fiber content and size on the flexural and tensile properties of the composite were investigated and were found to be highly significant and the effect of content on mechanical properties was more important than size.
Abstract: Black spruce and trembling aspen bark fibers and high density polyethylene were used to process bark–plastic composites by extrusion. Fibers of fine, medium, and coarse size and contents of 50% and 60% based on oven-dry weight were used. The effects of species, fiber content and size on the flexural and tensile properties of the composite were investigated and were found to be highly significant. Black spruce bark composites exhibited higher strength but showed more brittle behavior than aspen bark composites. The effect of content on mechanical properties was more important than size. Compared to wood flour composites, those from bark showed lower strength.
TL;DR: In this article, a flax/polypropylene commingled yarns were used to construct yarn composites, where all flax fibres were twistless and polypropylene fibres served as a carrier for the natural fibres during processing.
TL;DR: In this paper, the authors reviewed the research published in the field of natural fiber-reinforced polymer composites, with special reference to the effect of moisture absorption and alkali treatment on the mechanical properties.
Abstract: In recent years, the interest of scientists and engineers has turned over on utilizing all plant fibers as effectively and economically as possible to produce good quality fiber-reinforced polymer composites for structural, building, and other needs. It is because of the high availability of the natural resources in this green world. This has led to the development of alternative materials instead of conventional or man-made materials. Among the various natural fibers, roselle fibers were used traditionally in age-old applications in the form of the high-strength ropes and floor mats etc. It is of particular interest because its composites have high tensile strength as in jute, kenaf and hemp, besides having moderate impact strength properties compared with other natural fibers. This paper reviews the research published in the field of natural fiber-reinforced polymer composites, with special reference to the effect of moisture absorption and alkali treatment on the mechanical properties. However, the rev...
TL;DR: In this article, E-glass fiber (woven)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding and the mechanical properties were compared with those of the jute-based composites.
Abstract: Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m2, respectively. Then E-glass fiber (woven)-reinforced polypropylene-based composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when comp...
TL;DR: In this paper, a composite material based on whole stem kenaf fiber (WSK) and Ecoflex (biodegradable thermoplastic) was prepared by melt blending technique and characterized.
Abstract: The composite material based on whole stem kenaf fiber (WSK) and Ecoflex (biodegradable thermoplastic) were prepared by melt blending technique and characterized. The composites were prepared using different fiber loadings and the fiber was treated with various concentrations of NaOH solution by soaking for 3 h. The compounding of composite were carried out at different fiber loadings (10%, 20%, 30%, 40%, 50%) using Brabender internal mixer at 130°C for 10 min. The composites were then pressed using compression molding to produce biodegradable kenaf/Ecoflex sheets. The effects of kenaf fiber loading and NaOH treatment of WSK fiber surface on mechanical properties was examined. The results showed that 40% fiber loading improved the tensile strength properties and WSK fiber treated with 4% NaOH was found to enhance tensile and flexural properties compared with untreated fiber. The FTIR characterization showed that alkali treatment removes hemicellulose and lignin from WSK kenaf fiber surface.
TL;DR: In this paper, a polypropylene (PP)/banana fiber (BF) composites were prepared from PP fiber and short banana fiber and the polarity parameters of the chemically modified BF surfaces were investigated using the solvatochromic technique.
Abstract: Polypropylene (PP)/banana fiber (BF) composites were prepared from PP fiber and short banana fiber. BF surfaces were modified chemically to bring about improved interfacial interaction. The polarity parameters of the chemically modified BF were investigated using the solvatochromic technique. The empirical Kamlet–Taft solvatochromic polarity parameters such as hydrogen bond donating ability HBD or acidity (α), hydrogen bond accepting ability HBA or basicity (β), the dipolarity (π*), Gutman acceptor number (AN), Reichardts ET (30) values for the chemically modified BF was determined. It was found that the polarity of the BF was decreased after the chemical treatment. The fiber/matrix interactions were found to depend on the polarity of the BF. The improved fiber/matrix interaction was evident from the enhanced tensile and flexural properties. The lower impact properties of the treated fiber composites further point to the improved fiber/matrix interaction. The diameter of the chemically modified BF was measured using an optical microscope. Scanning electron microscopy studies revealed the changes of the surface morphology of the fibers after the chemical treatments.
Abstract: Bamboo fiber-reinforced HDPE composites were prepared employing melt blending technique followed by injection molding. A systematic investigation of the mechanical, dynamic, thermal, and morphological behavior of the composites was carried out. It was observed that the tensile and flexural properties increased with the increase in the fiber loading from 10% to 30%, beyond which there was a decline in the mechanical strength of the composites. Further, the composites treated with maleic anhydride grafted polyethylene (MAPE) exhibited improved mechanical properties, which confirmed efficient fiber—matrix adhesion. Dynamic mechanical analysis showed that the storage modulus increased in the untreated and treated composites as compared with virgin HDPE, indicating an increase in the rigidity of the matrix polymer with reinforcement. The morphology of the tensile fractured samples was also examined using scanning electron microscopic analysis. The thermal characteristics in the composites have been studied usi...
TL;DR: In this paper, the development of cellulose/clay nanocomposites for use as flame-retardant materials based on cotton is reported, which show significant improvements in thermal properties when compared with cellulose control sources.
Abstract: Cotton is the most important textile fiber for apparel use and is preferred to synthetic fibers for reasons such as comfort and feel. A major drawback of cellulosic fibers is flammability. The development of cellulose/clay nanocomposites for use as flame-retardant materials based on cotton is reported in this paper. Novel nanocomposite materials have been produced from cellulose with layered silicate clays used as the nanofiller material. Three different methods were attempted in producing these organic–inorganic hybrids. The nanocomposites show significant improvements in thermal properties when compared with cellulose control sources. The degradation temperature of the nanocomposites increased by 45 °C and the char yields for some compositions doubled those of the controls. The crystalline melt of the materials decreased by 15 °C. Tensile testing revealed an increase of approximately 80% in the ultimate stress of the cellulose/clay nanocomposites.
TL;DR: In this article, a study on the synthesis of pine needles reinforced polymer composites using phenol-formaldehyde (PF) as a novel polymer matrix through compression molding technique has been reported.
Abstract: The aim of the present research article was to study the perspectives of using natural fibers in polymer composites. Keeping in view the enormous advantages of natural fibers, in the present communication a study on the synthesis of pine needles reinforced polymer composites using phenol-formaldehyde (PF) as a novel polymer matrix through compression molding technique has been reported. Effect of fiber loading on mechanical properties such as tensile strength, compressive strength, flexural strength, and wear resistances has also been determined. Reinforcing of the PF resin with pine needles was done in particle form (200 µm). The present study reveals that mechanical properties such as: tensile strength, compressive strength, flexural strength, and wear resistance of the PF resin increases up to 30% fiber loading and then decreases for higher fiber loading when fibers are incorporated into the polymer matrix.
TL;DR: In this article, a jute fabric was characterized in terms of its saturated and unsaturated permeability, and it was found that fluid absorption and swelling are mechanisms present in natural fibers that reduce both permeabilities.
Abstract: The main goal of this work is to understand how the main processing variables are affected when glass fibers are replaced by natural fibers in reinforced plastics. In this publication, a jute fabric was characterized in terms of its saturated and unsaturated permeability. It was found that fluid absorption and swelling are mechanisms present in natural fibers that reduce both permeabilities. Fluid absorption removes fluid from the main stream as it travels through the reinforcement, acting as a sink component and thus decreasing flow velocity during the unsaturated flow. Also, the saturation of the natural fibers cause swelling, reducing the porosity and increasing flow resistance during saturated flow.
TL;DR: In this paper, the authors describe the moisture absorption behavior and its effect on mechanical properties of Lantana camara fiber reinforced epoxy composite and find that the tensile and flexural strength of composite decreases with moisture absorption.
Abstract: This paper describes the moisture absorption behavior and its effect on mechanical properties of Lantana camara fiber reinforced epoxy composite. Composite samples reinforced with different wt% of fibers were prepared by hand lay-up technique. Increase in tensile and flexural strength was observed with increase in fiber content up to 30%. Moisture absorption tests were carried out in three different environmental conditions (steam, saline water and sub-zero temperature). The moisture diffusivity constant and equilibrium moisture uptake were calculated. Moisture absorption of the studied composites was proved to follow the kinetics of a Fickian diffusion process. Tensile and flexural strength of composite were found to decrease with moisture absorption. After the mechanical tests, fracture characteristics analysis of the tested specimens was carried out to reveal a reasonable interaction between the reinforcement and matrix.
15 May 2010-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the flexural and indentation behavior of pultruded jute/glass and kenaf/glass hybrid polyester composites has been monitored using acoustic emission.
Abstract: The flexural (before and after cyclic loading up to 50% of ultimate load) and indentation behaviour of pultruded jute/glass and kenaf/glass hybrid polyester composites has been monitored using acoustic emission, and compared with that of kenaf fiber composites. In all hybrids, natural fiber content was 40 wt.%, while glass fiber one was 25 wt.%. Acoustic emission (AE) has been used for real-time monitoring during flexural and indentation loading: the analysis concentrated on AE resuming during reloading (Felicity ratio) and AE activity at low loads during unloading (crack closure effect). The results show that the introduction of this large amount of reinforcement appears quite effective on jute fiber reinforced laminates, although with a significant effect of fiber architecture, whilst it did not yield comparable results in kenaf fiber laminates. This was attributed to the insufficient fiber impregnation and to the need for improving the control of fiber orientation in the laminate.
TL;DR: In this paper, the hybrid composites of coir/silk unsaturated polyester-based composite with different fiber lengths were prepared and the variation of mechanical properties such as tensile strength, flexural strength, and compressive strength of these composites with various fiber lengths has been studied.
Abstract: The hybrid composites of coir/silk unsaturated polyester-based hybrid composites with different fiber lengths were prepared. Coir-silk fibers are taken in the ratio of 1 : 1, and these fibers are incorporated with unsaturated polyester resin with different fiber lengths like 1, 2, and 3 cm. The variation of mechanical properties such as tensile strength, flexural strength, and compressive strength of these composites with different fiber lengths has been studied. In the present work hand lay-up method was used for making the composites. Coir fibers are treated with NaOH and the effect of alkali treatment on the tensile, flexural, and compressive properties of the coir/silk hybrid composites has also been studied. Significant improvement in tensile, flexural, and compressive strengths of the coir/silk hybrid composites has been observed by these treatments.