Search

There is great interest in using natural materials in production, and this is due to ecological concerns. The two main pillars in developing natural composites are waste utilization and ensuring good economic returns. The biodegradability of natural fillers is one of the factors in expanding their use in natural fiber-reinforced composites. Naturally added composites, which are effectively used in different applications such as automotive, aviation, and maritime as well as design and construction industries, offer improved mechanical and tribological properties to the material. In the study where the mechanical effects of natural additives on the polymer were examined, waste banana peel powder and rice peel powder were added to polypropylene at different concentrations. After melt mixing of the components forming the composite, injection molding was performed. To determine the mechanical properties, tensile, hardness, Izod impact strength and density tests were carried out, and the microstructure examination of the composites was carried out with a scanning electron microscope. As a result of the studies, adding natural additives to the polymer caused the impact properties, elongation amount and tensile strength to deteriorate. In addition, with the increase in the reinforcement ratio, the density, hardness and elastic modulus of polymer composites increased. [ABSTRACT FROM AUTHOR]

Mycelium materials represent a new class of environmentally friendly materials for structural applications that can grow on low‐cost organic waste while achieving satisfactory thermal or acoustic insulation properties. The aim of this study is to grow a biocomposite of mycelium on flax tows and then use it as a reinforcement with a geopolymer matrix. To achieve this, three species of mycelium were selected, a culture process was carried out, and then samples of the composite were synthesized with a geopolymer matrix. To determine the utility in terms of structural applications, the density, compressive strength, and thermal conductivity of the samples were tested. Scanning electron microscope images were also taken to observe the microstructure. The results indicate that it is possible to produce a mycelium composite with a geopolymer matrix. A lower density was achieved for all samples than for the geopolymer without reinforcement. The coefficient of thermal conductivity was reduced only for the sample with one of the mycelia. The compressive strength for biocomposites was between 12.1 MPa–14.2 MPa, this value is enough for some engineering applications. [ABSTRACT FROM AUTHOR]

The aim of this research is to investigate basalt as a natural mineral-based fibre together with a vitrimeric resin as a sustainable alternative to standard composite materials. Vitrimers combine the properties of thermoset and thermoplastic polymers, enabling the repair of specimens and hence prolonging the lifetime of the composite material. The micro-mechanical characteristics between the basalt fibres and the vitrimer resin are reported and shown to match those of a standard Skyflex K51 epoxy resin. Discontinuous (4 mm) basalt fibres were employed to produce aligned discontinuous fibre-reinforced composites (ADFRCs) using the high-performance discontinuous fibre (HiPerDiF) technology. The mechanical characteristics of the laminates were investigated through tensile testing and the fracture zones were analysed under a scanning electron microscope. By normalising the results by their respective fibre volume fraction, it was discovered that the vitrimer–basalt ADFRCs exhibited, on average, a 4% higher strength and a 25% higher stiffness compared to their basalt epoxy counterparts. The repair potential of the vitrimer ADFRC specimens was explored during low-temperature compression repair. Two approaches were tested using double-sided local- and full-patch repair. Both successfully recovered a significant amount of their prime strength. In conclusion, the potential of the sustainable vitrimer–basalt composite is shown by its competitive mechanical performance. Combining this with the manufacturing flexibility, repair potential, and recyclability of the material, the vitrimer–basalt composite seems to be a competitive alternative to standard glass epoxies. [ABSTRACT FROM AUTHOR]

This work aims to study the cutting behavior of biocomposites under different controlled hygrothermal conditions. This investigation choice is motivated by the fact that natural plant fibers such as flax are characterized by their hydrophilicity which makes them able to absorb water from a humid environment. This absorption ability is intensified by increasing the conditioning temperature. The moisture diffusion process affects considerably the mechanical properties of the resulting composite, which causes many issues during the machining operations. In this paper, moisture diffusion, chip form, cutting and thrust forces, and scanning electron microscope (SEM) observations are considered to explore the cutting behavior of flax fiber-reinforced polylactic acid (PLA) depending on the hygrothermal conditioning time. Results reveal that moisture content in the biocomposite is significantly influenced by the conditioning temperature and the fiber orientation. Moisture content and fiber orientation affect both the curling behavior of the removed chip as well as the tool/chip interaction in terms of friction. The machinability of flax fiber-reinforced PLA biocomposites depending on hygrothermal conditioning time is then investigated using SEM analysis in addition to analytical modeling. An analysis of variance is used finally to quantify the observed results. [ABSTRACT FROM AUTHOR]

In recent years, the use of natural fibers has increased in manya applications, particularly in automotive industry, owing to their lightweight, high specific strength, recyclability, and ecological properties. This study aims to investigate the influence of copper filler on fiber-coated hybrid composite through mechanical and machining (CNC milling) characterization. Initially, the copper filler was characterized using the energy dispersive X-ray (EDX), particle size analysis (scanning electron microscope), and component analysis (X-ray diffraction (XRD)). Four coated natural fiber/wire mesh hybrid composite designs were developed and identified as hemp/mesh/ramie composite [HMR (1-4)]. In this work, 16 experiments were designed by central composite design (CCD) using Design Expert 13, considering the spindle speed, feed rate, and composite type as input parameters. The results indicate that copper filler particle proportion influenced the tensile strength and impact resistance of the HMR hybrid composite (16% & 15.42%). A fiber coating with a higher infill percentage reduces water absorption. The responses were estimated based on the resultant force and surface roughness, which were influenced by the weight percentage of the filler. In all the spindle speeds, the resultant forces are increased with raise in feed rates (120–600 mm/min). [ABSTRACT FROM AUTHOR]

The treatment method of natural fiber is one of the factors that influences its properties. There are several reports on sodium hydroxide (NaOH) treatment of many natural fiber. Though there are works on NaOH treatment of the fruits fiber, however, works on Borassus flabellifer Leaf fiber (BFLF) is sparsely reported. Hence no report on the optimum conditions for sodium hydroxide treatment of Borassus Flabellifer Leaf fiber. Therefore, this study aimed at establishing the optimum concentration and time for alkaline treatment on the properties of BFLF. The fiber extraction was carried out using water retting method for 24 h. Experimental design was carried out using Design Expert 12.0 adopting Central composite design in response surface methodology. NaOH concentration of 0–5 wt% and time of 1–12 h were used as the independent variables. The responses were water absorption, elongation (%), modulus of elasticity and tensile strength. The surface morphology of the fiber was studied using scanning electron microscope (SEM) and the functional group changes established using Fourier transform infrared (FTIR) spectroscopy to indicate effect of NaOH treatment (FTIR) spectroscopy to show the functional group changes due to NaOH treatment. The optimum concentration and treatment time was established as 2 wt% NaOH and 4 h, respectively, with corresponding responses of water absorption, tensile strength, modulus of elasticity and elongation (%) were 2.07%, 977.378 MPa, 6971.02 MPa, 5.178%, respectively. Using these optimum treatment conditions of time and NaOH concentration, the responses were validated to be 1.88%, 920.019 MPa, 6943.73 MPa, 4.99 mm having a desirability of 0.963. The SEM revealed rough surfaces and increased porosity for the treated fiber compared to the untreated. The FTIR spectra showed reduction in peaks representing lignin at wavelength of 3321.1 cm−1 to 3306.1 cm−1, which indicated that the NaOH treatment resulted to decrease in lignin in the fiber. The properties of the BFLF obtained at the optimum treatment conditions were within range of other fibers used in composite materials development, hence, BFLF treated at these conditions is suitable for composite development. [ABSTRACT FROM AUTHOR]

In recent trends, the usage of synthetic materials has been reduced by introducing natural fibres for lightweight applications. In this study, Madar (Calotropis gigantea) fibre is selected for the reinforcement phase (40%), and the epoxy polymer is blended with bran filler selected as a matrix material. To calculate hybrid composite mechanical characteristics, five composite laminates with different fibre/filler weight ratios were made. The results show that when the weight ratio of madar fibre increased, the superior mechanical properties were observed in the composite laminate sample (A), such as tensile strength (20.85 MPa), flexural strength (24.14 MPa), impact energy absorption (23 J) compared with an increasing the weight ratio of bran nanofiller to this composite material. At the same time, increasing bran nanofillers can improve thermal stability up to 445 °C of degrading temperature. To analyse the surface interaction between the madar fibres, bran nanofillers, and epoxy matrix by conducting the scanning electron microscope (SEM) analysis before subjecting to the mechanical test and also to identify the failure mode by conducting the SEM test after the laminates are broken during the mechanical tests of the hybrid composite. [ABSTRACT FROM AUTHOR]

Desmostachya bipinnata (Dharbe grass) has been used as a sacred plant in many of the rituals in India. A composite was prepared using hand layup using Desmostachya bipinnata particle with mesh size of 600microns. The specimens were evaluated for tensile, electromagnetic shielding effectiveness. The specimens were also investigated using scanning electron microscope. It is observed that the composite yielded better results in terms of tensile strength, but the results obtained for electromagnetic shielding effectiveness were not encouraging. The insufficient electromagnetic shielding effectiveness might be attributed to the size, shape, or distribution of the Desmostachya bipinnata particles within the composite. [ABSTRACT FROM AUTHOR]

In recent trends, the usage of synthetic materials has been reduced by introducing natural fibres for lightweight applications. In this study, Madar (Calotropis gigantea) fibre is selected for the reinforcement phase (40%), and the epoxy polymer is blended with bran filler selected as a matrix material. To calculate hybrid composite mechanical characteristics, five composite laminates with different fibre/filler weight ratios were made. The results show that when the weight ratio of madar fibre increased, the superior mechanical properties were observed in the composite laminate sample (A), such as tensile strength (20.85 MPa), flexural strength (24.14 MPa), impact energy absorption (23 J) compared with an increasing the weight ratio of bran nanofiller to this composite material. At the same time, increasing bran nanofillers can improve thermal stability up to 445 °C of degrading temperature. To analyse the surface interaction between the madar fibres, bran nanofillers, and epoxy matrix by conducting the scanning electron microscope (SEM) analysis before subjecting to the mechanical test and also to identify the failure mode by conducting the SEM test after the laminates are broken during the mechanical tests of the hybrid composite. [ABSTRACT FROM AUTHOR]

Bamboo fiber is one of the strongest natural fibers with high strength‐to‐weight and stiffness‐to‐weight ratios and can be used economically for manufacturing fiber‐reinforced composites. In this paper, bamboo fabric‐reinforced epoxy composite is manufactured and its tribological properties for load‐bearing applications are investigated. Sliding wear tests are conducted using a linear reciprocating tribometer and the effect of dry and lubricated contact conditions, applied load, sliding speed, temperature, and woven fabric direction on the coefficient of friction and wear rate are investigated. A scanning electron microscope is used to define the wear mechanisms at room and elevated temperatures. It is observed that the fabric orientation influences the mechanical and tribological performances of the composite material. Wear rate increases at higher loads and working temperatures; however, the effect of sliding speed is not remarkable, especially under lubricated contact conditions. The results present in this paper can be used for designing bamboo‐reinforced epoxy composites for load‐bearing applications, under different working conditions. [ABSTRACT FROM AUTHOR]

Hemp is a good option for polyethylene additives because of its high cellulose and fibrous content. This study aims to modify natural hemp fibers with the maleic anhydride/ionic liquid method, manufacture the composites, and compare the thermal and mechanical properties of natural hemp fiber and hemp cellulose. In this study recycled polyethylene as a binder, and filling ratios between 0 and 50 (wt/wt)% are investigated as a parameter. Differential scanning calorimeter and thermomechanical analysis were performed, and it was determined that the coefficient of thermal expansion from 973 to 147 ppm/K. It was determined that the strength of composite materials obtained from cellulose fibers with maleic anhydride/liquid ionic modification improved by around 20% from 19.5 to 24.4 MPa. In addition, as a result of scanning electron microscope analyses performed on the fractured surfaces, it was determined that the pressure, temperature, and time were suitable for producing composite materials. This work shows the potential of recycled polyethylene/hemp composites as a sustainable green material with simple fabrication procedure and useful mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

There has been an increasing trend of using natural fibre reinforcements as an alternative to manmade fibre reinforcements for engineered composite applications. Natural fibres are alternative composite reinforcement materials due to their biodegradability, inexpensiveness, abundance and excellent physical properties. This study aims at analysing the mechanical properties of the fabricated bio-composite from polyester resin reinforced with silk waste fabric. The specific objectives of this work are to characterise physical and mechanical properties of silk waste fabric, fabricate a bio-composite from silk waste fabric treated with zinc oxide nanoparticles and polyester resin and to analyse the static mechanical properties (tensile, flexural and impact). The silk waste fabric is characterized and the composite fabricated using hand lay-up technique and a mould with dimensions 360 × 210 × 4 mm. Central composite design is used in the design of experiments, and the fibre weight fraction was varied from 11 to 25%. Treatment with nanoparticles is done by soaking silk waste fabric in a 6% concentration of zinc oxide nanoparticles and 1% citric acid. A sonicator uses to evenly distribute the nanoparticles in the solvent, and the fabric is coated using the pad dry cure method. The fabricated composites are cured at room temperature for 24 h under consolidated pressure of 2.65 kN/m2. The mechanical properties of the composites are determined using D790, D638 and D6110 ASTM standards, whereas the morphology is investigated using a scanning electron microscope. The areal density of the silk waste fabric is 76 g/m2, and its tensile strength was 16.80 MPa. The tensile, flexural and impact strengths of uncoated composites are 27.92 MPa, 52.13 MPa and 32.17 kJ/m2, respectively. The flexural and tensile strengths of the coated bio-composites increase with increasing fibre weight fraction up to peak values of 32.23 MPa and 53.47 MPa, respectively. Bio-composites produced with silk waste fabric treated with nanoparticles had slightly better strengths (tensile 32.23 MPa and flexural 53.47 MPa) compared to bio-composites with non-treated silk waste fabric (tensile 27.92 MPa and flexural 52.13 MPa). The static mechanical properties attained in this study reveal that these bio-composites may be used for non-structural applications for instance partitioning walls and ceiling boards. The study recommended future research studies on increasing the number of plies beyond six with different fabric weave designs of twill, satin, sateen and warp rib and use of thermal evaporation as a coating technique of nanoparticles onto silk waste fabric to establish their effect on mechanical and thermal properties and morphology. [ABSTRACT FROM AUTHOR]

Jute is a ligno-cellulosic natural fiber that ranks second in terms of the volume of cellulosic fibers and is extensively utilized for technical textile applications. The goal of this study is to determine the flame-retardance (FR) properties of pure Jute and Jute-Cotton fabrics treated with Pyrovatex CP New at concentrations of 90% (owf), M:L: 1:7. Both fabrics exhibited a substantial improvement in flame-retardancy. After the ignition period, the recorded flame spread time in both FR treated fabrics was zero seconds; whereas for untreated Jute and Jute-Cotton fabrics, the flame spread time was measured 21 s and 28 s, respectively, to burn their entire length (15 cm). Within these flame-spread times, the length of the char was 2.1 cm and 2.57 cm in the Jute and Jute-Cotton fabrics, respectively. After FR finishing, on both fabrics in the warp and weft directions, the physico-mechanical properties significantly decreased. The deposition of flame-retardant finishes on the fabric surface was determined by Scanning Electron Microscope (SEM) images. According to Fourier Transform Infra-Red Spectroscopy (FTIR) analysis, the flame-retardant chemical had no effect on the inherent properties of the fibers. Thermogravimetric analysis (TGA) analysis revealed that FR treated fabrics had early degradation, resulting in the formation of more char than in the untreated samples. After FR treatment, both fabrics showed a significant improvement in residual mass (more than 50%). Although the formaldehyde content observed in the FR treated samples was significantly greater, it was still within the permitted limit formaldehyde content in textiles intended for outerwear and not worn next to the skin. The results of this investigation demonstrate the potential use of Pyrovatex CP New in jute-based materials. [ABSTRACT FROM AUTHOR]

Global warming has led to a change in climatic conditions. Since 2006, drought has contributed to a reduction of food production and other agriculture-based products in many countries. The accumulation of greenhouse gases in the atmosphere has caused some changes in the composition of fruits and vegetables, making them less nutritious. To analyse this situation, a study was conducted on the effect of drought on the quality of fibres provided by the main fibre crops in Europe, namely flax (Linum usitatissimum). The experiment consisted of growing flax under controlled comparative conditions with designed different irrigation levels, such as 25%, 35% and 45% field soil moisture. Three varieties of flax were grown in 2019, 2020 and 2021 in the greenhouses of the Institute of Natural Fibres and Medicinal Plants in Poland. Fibre parameters, such as linear density, length and strength, were evaluated according to relevant standards. In addition, scanning electron microscope images of the cross-section and longitudinal view of the fibres were analysed. The results of the study indicated that deficiency of water during the flax growing season resulted in lowering of fibre linear density and tenacity. [ABSTRACT FROM AUTHOR]

The present study concerns the physico-chemical, structural, mechanical and thermal characterization of Acacia pennata, a natural and almost inexpensive fibre, as a potential reinforcement in polymer composites. The effect of treating the fibre with sodium acetate to increase its qualities has been seen through the use of thermogravimetric analysis, scanning electron microscope (SEM) analysis, X-ray diffraction (XRD), mechanical property tester, and Fourier transform infrared spectroscopy (FTIR). According to XRD analysis, the elimination of lignin and wax-like impurities resulted in an increase in the AP fibre's crystalline index (79.73%). The fibre's thermal stability was also discovered to be 365 °C. Tensile strength (557.58 MPa) and elongation at break both increased by 2.9% after treatment with sodium acetate. The surface nature and quality of AP fibres improved after sodium acetate treatment. It was confirmed by the reduction of chemical compositions (such as hemicellulose, lignin and pectin). Given its density, the fibre can be suggested as a reinforcement in polymer composites for light-weight applications because its lightweight property will be more useful for composite manufacturing. [ABSTRACT FROM AUTHOR]

A persistent rise in the costs of construction materials has led to the need to address this problem in line with the Sustainable Development Goals. This research employed vegetal soft and rigid fibers in a screed mortar to produce a sustainable fabric–cement matrix. Four different vegetal-dried fibers (hemp, flax, miscanthus, and bamboo) with dosages of 0.4, 0.6, 0.8, 1.2, 2, and 4 kg/m3 were used. Laboratory investigations were slump test, bulk density, air occluded, shrinkage, and mechanical strength. Scanning Electron Microscope (SEM) assessments were performed and analyzed on the natural fibers and the screed formulation. The results highlight that fiber dosages significantly influence the above-mentioned properties. [ABSTRACT FROM AUTHOR]

To address the need for wear-impenetrable packaging in shipment and related sectors, a treated hemp filler-reinforced epoxy composite manufactured in-house is subjected to tribological testing to assess its utilization under extensional load. The surface modification approaches are utilized on hemp fibres by employing alkali treatment with sodium hydroxide solution. Wear tests are executed on the developed samples in a dry atmosphere employing a pin-on-disc (POD) tribometer for three variable applied forces (5, 10, and 15 N), a sliding velocity of 550 RPM, and three sliding lengths (1000, 2000, and 3000 m) for friction against a stainless-steel disc. The mechanical properties (density, tensile, and flexural) of the composites are also assessed. The results indicated the effects of operating parameters and filler percentage in the test samples. Among all composites, 2.5 and 7.5 wt% hemp filler composite has generated the minimum wear and better mechanical characterization. Employing scanning electron microscope, the physical characterization of composites is carried out where fractures, debonding and deformation on the surfaces are seen. Apart from the tests, the wear properties of the composites with varying filler percentages are also predicted using artificial neural network (ANN) models. [ABSTRACT FROM AUTHOR]

Natural fiber composites are now more costly than traditional building materials. Currently, industries are moving from traditional materials to natural fiber composites, and the price of natural fiber should be reduced through greater utilization of industrial production. This work aims to determine how matrix alteration affects the interlaminar characteristics of a hemp fiber-reinforced epoxy composite containing nano silicon oxide particles. Interlaminar modulus of rupture in Types I and II is assessed using dual cantilevered beams and end-notched deformation testing samples. Mechanical mixing and sonication are used to blend nanoscale SiO2 (30 nm) into the resin at concentrations of 0, 0.2, 0.4, and 0.6 wt%. The composites were made using the compression molding method. The composites were tested according to the American Society for Testing and Materials standards after manufacturing. The findings show that adding nanoparticles enhances interlaminar toughness values. Interlaminar fracture toughness improved by 20.25% and 30.35% for 0.4 wt% SiO2, respectively. The fiber matrix interaction and failure causes are examined using scanning electron microscope images. [ABSTRACT FROM AUTHOR]

The influences of natural bamboo fibers (BFs) weight fraction on the microstructure, quasi-static and dynamic compressive responses of the epoxy resin matrix composites were investigated with the aid of scanning electron microscope, electronic universal testing machine and the modified Split Hopkinson pressure bar (SHPB) setup. The quasi-static compressive properties of the BFs/epoxy resin matrix composites suggested that the compressive strength were strongly improved with the addition of the natural BFs, which was attributed to the excellent strengthening effect. When the BFs content increased up to 15 wt.%, the compression ratio of the BFs/epoxy resin matrix composites showed 11% reduction than that of the unmodified epoxy resin. Moreover, the stress and strain were linear at the initial part but nonlinear when stress exceeds a certain value. SHPB impact tests results indicated that, compared with the pristine epoxy resin, the natural BFs reinforced epoxy matrix composite with 15 wt.% BFs exhibited the highest dynamic compressive strength, compression modulus and the best strengthening effect. Epoxy resin matrix composites also showed an obvious effect rate effective under impact load. Similar to that in the quasi-static compressive test, the addition of natural BFs has a positive effect in improving the compressive strength of the epoxy matrix. [ABSTRACT FROM AUTHOR]

In this study, an attempt is made to check whether a hybrid composite made up of both synthetic and natural fibers (Carbon and Cordia Dichotoma respectively) can be made bio-degradable, at least to some extent, without much compromising on the mechanical properties. Hybrid composites were prepared by reinforcing alkali treated Cordia dichotoma and carbon fibers into epoxy resin using hand lay-up method. By varying the number of layers of fibers in the composite specimen and fixing 20% fiber weight for all composites, nine distinct combinations of specimens were prepared. The maximum tensile strength of 386.68 MPa, flexural strength of 647.08 MPa, and impact energy of 4.82 J were obtained for composites produced with pure carbon fiber, whereas hybrid composite exhibit tensile strength of 367.76 MPa, flexural strength of 646.41MPa and impact energy of 4.74 J. The interfacial bonding between the fibers and matrix of tested specimens was studied using a scanning electron microscope (SEM), as well as the arrangement of fibers within the matrix for the manufactured composite. Thermogravimetric analysis (TGA) was used to investigate thermal stability, and it was found that it was thermally stable up to 415°C. 9. Crystallinity value increases from 20% carbon fiber to 20% alkali fiber. [ABSTRACT FROM AUTHOR]

Recent advances made in concrete fibers have made them one of the concrete's recommended ingredients, mainly to eliminate the drawbacks associated with the weakness of cementitious materials, such as concrete, in tension. The addition of fibers, however, introduces extra cost and labor requirements, while selecting an appropriate choice and dosage of fibers has still remained a standing question. To address the outlined issues, the current study investigates the development of fiber‐reinforced concrete (FRC) mixtures with a focus on achieving superior mechanical properties with a low dosage of synthetic fibers. For this purpose, three choices of macrofibers were examined. The investigations spanned four dosages of each macrofiber mixed with three dosages of a microfiber included to ensure adequate resistance to early‐age, shrinkage‐induced strains. The experiments conducted on the developed hybrid FRC mixtures systematically measured workability, as well as compressive, splitting tensile, and flexural strength properties. The test results were then paired with the micro‐scale monitoring of the bond between individual macrofibers and the concrete matrix through scanning electron microscope images. The outcome shed light on how each of the macrofibers of choice contributed to improving the FRC's mechanical properties. This paved the way to benefit from a minimum dosage of them to achieve the expected structural response, while avoiding crack formation and propagation in various applications. [ABSTRACT FROM AUTHOR]

The acrylic acid treated rattan fiber reinforced epoxy (RF/Epoxy) composite has been fabricated by taking various weight percentages (5, 10, 15, 20, and 25 wt%) of fibers using hand layup followed by compression molding technique. The optimum fiber loading has been determined by regression analysis and it is found that 18 wt% of rattan fiber gives maximum tensile strength. The interaction of rattan fiber with epoxy matrix has been studied by Fourier transform infrared spectroscopy and X-ray diffraction. Scanning electron microscope (SEM) has been used to study the morphology of chemically modified rattan fiber and RF/Epoxy composite. The mechanical, thermal, and dynamic mechanical thermal properties of 18 wt% RF/Epoxy composite have been studied as per ASTM standards. From the results, it is observed that RF/Epoxy composite gives best properties at optimum (18 wt %) fiber loading. The maximum tensile strength and flexural strength of the composite are found to be 47.5 and 121 MPa, respectively, which is better in comparison to other natural fiber composites used for manufacturing different automobile body parts. Hence, it can be concluded that 18 wt% RF/Epoxy composite can be considered as a potential candidate for automotive body parts. [ABSTRACT FROM AUTHOR]

The aim of the effort is to estimate the effect of jute and bamboo fibers with silica fume (SF) of different proportions on mechanical properties of concrete. Cube, cylinder and prism specimens are tested to determine the compressive, split tensile and flexural strength at 14 and 28 days of curing. To verify the experimental findings, further Artificial Neural Network (ANN) analysis is conducted. The study employs neural network (NN), such as the Neural Network-Leven Berg–Marquardt and the Neural Network Gradient Descent. In this investigation, feed-ahead lower back promulgation neural networks were employed. The NN predicted values are validated with actual values and the variation is found to be within 10% only. The predicted ANN results are compared with existing Response Surface Methodology model. Under compressive, split tensile and flexural load, the broken surface is examined at a smaller-scale level with a scanning electron microscope (SEM). The experimental results show that concrete with 0.5% bamboo fibers and 0.5% jute fibers with 10% SF had higher influence on the mechanical properties of concrete. When comparing ANN results, the suggested ANN model showed high level of accuracy in estimating the mechanical properties of natural-fiber-reinforced concrete. SEM examination displayed the failure pattern of concrete and fibers. [ABSTRACT FROM AUTHOR]

Natural fiber reinforced composites are attracting the attention of industries toward a sustainable and environment-friendly material for the future demands. The main drawback pertaining to the use of natural fiber composites lies in its inferior strength in comparison to its counterpart synthetic fibers. This research focuses on improving the fracture toughness of woven jute fabric mat with different orientations (0°, 30° and 45°) in epoxy resin by incorporating fillers and tested in universal tensile testing machine. Silicon carbide (SiC) particles of three sizes 26 µm, 54 µm and 72 µm were incorporated in the matrix in different weight ratios (5%, 10% and 15%). The fracture toughness of the jute/epoxy composites increases with the increase in the amount of SiC particles up to 10% addition and then it shows decreasing trend with further addition. The fracture toughness values show upward trend when the fiber orientation changed from 0° to 45°. Fractography of the tested specimen captured by scanning electron microscope which reveals the fracture of fibers and micro cracks in the epoxy matrix due to the applied load. Analysis of variance (ANOVA) is also conducted for predicting the most influencing parameters on the fracture toughness. [ABSTRACT FROM AUTHOR]

Synthetic fibers are restricted from being used as reinforcements due to increasing awareness of environmental issues and strict laws from government agencies. In recognition of this, the engineering and scientific communities switched their attention to using natural fibers as reinforcement in polymers to make sustainable composites. The fiber was extracted through the water retting process, and characterized from the stem of the Tithonia diversifolia (TD) plant. Physical, chemical, and mechanical properties were investigated and it was found that this fiber has high cellulose content of 65.33 wt.%, and less wax content of 0.67%. X-ray diffraction (XRD) confirmed the crystallinity index as 45%. Surface morphology was carried out through Scanning Electron Microscope (SEM) analysis. Fourier Transform Infrared Spectroscopy (FTIR) results confirmed the chemical functional groups. Thermogravimetric Analysis (TGA), TG and DTG curves were used to evaluate the fiber thermal stability. This result confirms that TD fiber can be used as potential fiber reinforcement in biocomposites. [ABSTRACT FROM AUTHOR]

The current study investigated the use of polyester synthetic (PES) fiber and basalt (BS) and bagasse (BG) natural fibers on the strength and mechanical behavior of sandy soil in pavement construction projects. A series of California bearing ratio (CBR) and indirect tensile strength (ITS) tests were performed on fiber contents (FC) of 0.5,1 and 2% and fiber lengths (FL) of 2.5, 5, and 7.5 mm. Findings show that the maximum California bearing ratio (by increasing 3.3 times) and indirect tensile strength (by increasing 2.98 times) are obtained in the length of 7.5 mm and the content of 2% for polyester and basalt fibers, respectively, which is also evident in the scanning electron microscope (SEM) test results. Also, based on the analysis of variance (ANOVA) and according to various factors including P-value (<0.05), it was determined that the contrast between the values is statistically significant. Due to California bearing ratio – indirect tensile strength and California bearing ratio – resilient modulus experimental relationships, the relationship between resilient modulus-indirect tensile strength was provided with very good correlation coefficients. Furthermore, sensitivity analysis revealed that California bearing ratio and indirect tensile strength values are noticeably influenced by fiber content variations. [ABSTRACT FROM AUTHOR]

Fiber‐reinforced composites have found their prominent place in various applications, including aerospace, automobile and marine manufacturing industries, because of outstanding properties obtained during composite preparation. One such aspect of improving the composite property is hybridization, where natural fibers (or both natural and synthetic fibers) are combined to obtain different composite structures for diverse applications. This research aims to hybridize the composite considering Kenaf fabric and Kevlar fabric reinforced in an unsaturated polyester matrix with different proportions. Three different laminate sequences (L1, L2, and L3) were developed by considering the fabric's stacking sequence, weave pattern, and orientation. The composite laminates prepared were tested where Taguchi's method (L9 orthogonal array) and artificial neural network were used to study influencing parameters for tribological behavior of the composite. From the practical information, a prediction model from the artificial neural network is applied to forecast the wear rate of the laminates at a broader range of operating factors beyond and within the test phase. The microstructures of the worn surfaces were investigated from a scanning electron microscope to confirm the wear principle of the laminates under different cases. [ABSTRACT FROM AUTHOR]

This study deals with the extraction and testing of natural cellulose fibers obtained from the barks of Ziziphus nummularia (Burm. f.) Wight & Arn. plants. The extraction of Z. nummularia fibers from its plant barks was done by water retting. The extracted fibers were analyzed for their chemical, crystalline, thermal, mechanical, and physical properties. Surface characteristics of the fibers were examined using a scanning electron microscope and an atomic force microscope. The test results showed that cellulose content was 52.34%. The crystalline index was 45.77% whereas the crystallite size was 2.01 nm. Thermogravimetric analysis showed a maximum degradation temperature of 348°C. The morphological properties showed that Z. nummularia fibers had a good surface roughness that helps in forming interlocks with the matrix on its usage in polymer matrix composites. [ABSTRACT FROM AUTHOR]

The natural fiber extracted from water hyacinth waste could be used for making natural fiber polymer composites. The main intent of this manuscript is to develop polymer composite materials reinforced by aquatic wastewater hyacinth natural fibers having varying lengths. The water hyacinth fibers were extracted using a mechanical drum extractor followed by a drying process at a speed of 320 rpm. Mechanical testing of the composites was conducted as per the relevant ASTM standard and subsequently, thermo gravimetric analysis was also conducted to assess the thermal characteristics of the composites. Fourier-transform infrared spectroscopy (FTIR) and X-Ray diffraction (×RD) techniques were employed to characterize the elemental and microstructural properties of the composites. A 20 mm fiber length with a 30% fiber content resulted in the best mechanical properties. Fractured surfaces from the composite samples are evaluated by using a scanning electron microscope (SEM). Brittle fracture, fiber pulled out, fiber clusters are identified as the general failure characteristics of the composites. This study demonstrated that the hyacinth fiber reinforced epoxy resin composite could be useful for developing particleboard products, as well as other lightweight products. [ABSTRACT FROM AUTHOR]

The fundamental aim of this study is to acquaint a novel sustainable cellulosic fiber obtained from beetroot plant for using in composite and textile industries. Natural cellulosic beetroot fibers were extracted from beetroot plant with biological degradation method. In order to determine the fiber properties, chemical, physical, and instrumental tests were carried out for fibers. The surface of samples was scanned using a scanning electron microscope (SEM). The elemental composition of fibers was analyzed with an energy dispersive X-ray analysis (EDX) device. Crystallographic properties of fibers were determined with X-ray diffraction (XRD) technique. Thermal degradation behavior of fibers was investigated with thermogravimetric analysis. SEM analyses show that the fibers have a cylindrical morphology and a 284.04-μm diameter. EDX analysis revealed that the fibers have 52.39% carbon and 47.46% oxygen. The XRD analysis indicates that beetroot fiber contains crystallinity index (Crl) of 87% and crystallite size (L) of 3.92 nm. According to the TGA analysis, the major degradation of fibers occurs at a temperature range of 288.09°C to 358.54°C. Mechanical characteristic of fibers was detected with tensile test, which provided information about strength, elongation, Young's modules, and microfibril angle. The tensile strength, elongation, and Young's modules of fibers are 50.68 MPa, 7.72%, and 6.56 GPa, respectively. The results show that mechanical behaviors and chemical characteristics of beetroot fibers are compatible with other cellulosic fibers. [ABSTRACT FROM AUTHOR]

The ecological conservation in the current global scenario has led scholars to use natural fibers as a reinforcement in composites that resulted in the exploration of new natural cellulose fibers. This research investigates the extraction and characterization of natural cellulose fibers from the stems of Buxus sempervirens (BS) plants, which are used to produce various products. Manual retting of stems resulted in Buxus sempervirens fibers production, which was then evaluated for their physical, chemical, thermal, crystallographic, and morphological characteristics. The results elucidated that BS fibers had a cellulose percentage of 51.78%, 18.42% hemicellulose, and 17.36% lignin. The Fourier Transform Infrared Spectroscopy results validated the chemical constituents. Crystallographic investigations utilizing X-Ray diffraction revealed a crystalline index of 18.05%. The thermogravimetric analysis of BS fibers showed char residue of 33% and a maximum degradation temperature of 263°C. The BS fibers revealed good surface interlocks that can be inferred from Scanning Electron Microscope. Thus, from the results compared with other natural fibers, we demonstrate that Buxus sempervirens fibers can be effectively used as reinforcement in polymeric composites. [ABSTRACT FROM AUTHOR]

Natural fibers are growing attention in the replacement of synthetic glass fiber due to their unique properties. The present work focuses on the wear properties of Epoxy with Cissus quadrangularis Stem Fiber (CQSF) particulatefilled red mud composite using Taguchi L9 orthogonal array technique. A three-body wear test rig is done with four input parameters and three levels such as velocities (0.75 m/s, 1.5 m/s and 2.25 m/s), sliding distances (400 m, 600 m and 800 m), applied loads (10 N, 20 N and 30 N) and red mud filler (0%, 5% and 10%) to observe the wear behavior of the developed composites. The level of impact on specific wear rate due to various input parameters such as velocity, distance, load and filler was computed. The hardness of the samples was increased by 10.7% for 5 wt.% red mud addition and 14.2% for 10 wt.% of red mud addition. The overall mean for the signal-to-noise (S/N) ratio of the specific wear rate of the specimen was found to be 34.62 dB, respectively. Finally, the experimental result and predicted theoretical result were validated after taking the conformation experiment. The wear mechanism of the composite materials after the abrasive wear test was substantiated using scanning electron microscope (SEM) analysis. [ABSTRACT FROM AUTHOR]

Natural cellulose fibers have a great potential for the development of new alternative reinforcement materials that are used in various polymer composite applications. In this study, waru tree trunk fiber was extracted and treated with NaOH and Silane. Meanwhile, the characteristics of chemical, morphological, mechanical, and fiber surfaces were determined through composition analysis, Fourier transforms infrared (FTIR), scanning electron microscope (SEM), and single fiber test. The results showed that the cellulose content increased with the addition of silane treatment which was supported by the high crystalline index of 63.02% waru bark fiber. Based on this treatment, the tensile strength of the single fiber had the highest value of 243.94 Mpa. Therefore, this fiber has the potential as a new reinforcement development in polymer-based products. [ABSTRACT FROM AUTHOR]

In the present investigation, the influence of chemical treatment on the structural, morphological, thermal, and weathering behavior Eulaliopsis Binata (EB) fiber was studied. Composites were fabricated containing both untreated and chemically treated (with acetone, alkali, and benzoyl chloride) EB fibers. The mechanical characterization of the developed composites was carried out for both treated and untreated EB fiber composites to assess the effect of chemical modification on the mechanical properties. The maximum tensile and flexural strength were observed for benzoylated fiber composites. The percentage increase in the tensile and flexural strength of 30 weight fraction EB fiber composites was found to be 43.2% and 47.05% with respect to untreated fiber composites. The fractured surfaces of the specimens were studied using a Scanning Electron Microscope (SEM) to explore the fracture mechanisms of the developed composites. [ABSTRACT FROM AUTHOR]

This study is intended to improve the methodology to calculate the tensile properties of natural coconut fiber and increasing confidence in the use of sustainable natural fibers as reinforcing in composites used for different components in the naval industry. Coconut fiber is an agribusiness by-product that has been shown to have the potential for the development of new materials. The morphology of different species of coconut fiber was studied, and their mechanical tensile properties were determined. The coconut fibers were tested under direct tension in a universal testing machine, and the cross-sectional area of the fibers was calculated using images obtained in an optical microscope and a scanning electron microscope. The study assessed the incidence of key factors to determine coconut fiber mechanical tensile properties including different area measuring methods and the percentage of lumens present through an image analysis software called ImageJ. The results indicate that coconut fiber has a round-shaped cross-section, and the percentage of lumens is between 15% and 27%. Therefore, the effective area is reduced increasing the fiber's ultimate resistance to tension. [ABSTRACT FROM AUTHOR]

Natural fibers as reinforcement of cementitious matrices have become a material with greater toughness, strength, and sustainability for the construction industry. However, their use can generate some inconveniences due to the high-water absorption of the natural fiber, which affects the production and durability of composites. In this work, the autoclave treatment of sisal fibers was carried out in order to determine time and pressure values that result in a lower water absorption of the fibers. The fibers were exposed to 1.0 or 1.5 atm of vapor pressure for 30, 60 and 90 min and their structures were evaluated by X-ray diffraction, differential scanning calorimetry and scanning electron microscope. The effect of treatment on fiber dimensional variation, fiber mechanical properties, and fiber-matrix bond was investigated. Composites reinforced with treated fibers were produced and subjected to bending tests. The results indicate that the autoclave treatment with 30 min and 1.5 atm reduced the water absorption from 134% to 90% and the dimensional variation from 63% to 18%. However, structural modification of the fibers reduced the fiber's tensile strength and bond strength. Composites reinforced with treated fibers showed lower flexural strength and toughness than those reinforced with natural fibers. [ABSTRACT FROM AUTHOR]

This study aimed to investigate on elasticity, degradation, and mechanical strength of sodium carboxyl methyl cellulose (SCMC) and calcium alginate (CA)-based scaffolds and their effect on fibroblasts' proliferation and adhesion. Using electrospinning technique by employing natural polymers provides a progressive approach in tissue engineering by producing similar structure with adjustable properties. Scanning electron microscope (SEM) was applied to observe the morphological and textural properties. Physico-chemical properties were studied using FTIR, tensile strain, contact angle, in vitro degradation, and water absorption test, and the biological properties were conducted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and SEM observations. The results showed that a bead-free fibers was produced with over 80% porosity. CA resulted in enhancing elasticity, wettability, water uptake absorption, and increasing the rate of biodegradation. Biological assessment revealed that fibroblast cells were adhered and proliferated on SCMC/CA scaffold better comparable with pure SCMC scaffold. The overall findings denoted to the chemical, mechanical, hydrophilicity and biological suitability of SCMC/CA nanofiber scaffolds that make it a promising candidate for further studies toward skin tissue engineering applications. [ABSTRACT FROM AUTHOR]

In the present research, our aim is to study effects of alfa fiber content, alkali, maleic anhydride grafted polypropylene (MAPP), and the combined treatment (alkali and MAPP) on the tensile and flexural behavior of alfa fiber-reinforced polypropylene (PP) composites. These composites were produced using a single-screw extruder followed by an injection molding process. Both fibers and composites were characterized using optical and SEM microscope in order to evaluate the interfacial adhesion between the fibers and the matrix. From the main results, the tensile modulus and flexural strength of 30% untreated Alfa fiber/PP composites were found to increase significantly compared to those of PP. Meanwhile, there is no significant increase in terms of the tensile strength and the flexural modulus. Moreover, the composites with a combined treatment have shown significant effect on the tensile and flexural properties compared to untreated composites and the treated ones. The SEM observation of the morphology of alkali treated fibers exhibited an increase in the surface roughness because the removal of impurities. In addition, SEM photos of the fractured surface of composites reveal the improvement of the fibers and PP matrix interface quality by treatments, in particular the combined treatment. [ABSTRACT FROM AUTHOR]

The increasing demand for eco-friendly materials and technology has made the industry focus on bio-compatible composites. This made the researchers explore the potential of eco-friendly, bio-degradable, and inexpensive banana fibre for automotive applications. This work reports the preparation and testing of banana fibre natural hybrid composite fibres randomly oriented with and without adding silica filler (5–15 wt.%) through a hand lay-up process. The mechanical properties such as tensile modulus, flexural modulus, hardness, impact strength, and water absorption capacity were measured. Composite specimens having a fibre length of 30 mm (15 wt.% of silica) exhibited better mechanical properties. The hardness, tensile, flexural, and impact strength measured were 46.74 HV, 54.71 MPa, 127.94 MPa, and 15.19 kJ/m2. The results showed significant improvement in mechanical properties in silica-reinforced hybrid composite compared to composites without silica filler. The wt.% of banana fibre increases, and the number of free hydroxyls (-OH) groups increases in cellulose, increasing moisture absorption. The pattern in which the composite absorbs the moisture at room temperature is called "Fickian behaviour." Furthermore, scanning electron microscope (SEM) characterisation studied the interaction between fibre matrix and the distribution of silica reinforcement. This research concludes that bio-composites that exhibit improved mechanical properties are eco-friendly and are found to be suitable for automotive applications that meet present-day requirements. [ABSTRACT FROM AUTHOR]

Natural fiber capability as an acoustic panel is subjected to physical properties of the fiber. Chemical treatment was implemented in this study to improve kenaf fiber performances and utilized as a sound absorption material. This research aims to use sodium hydroxide (NaOH) treatment from 1% to 8% concentrations on kenaf fiber. Physical changes on the kenaf fiber strands due to NaOH treatment were observed using Scanning Electron Microscope (SEM). The subsequent effects on sound absorption were measured using Impedance Tube to determine the sound absorption coefficient (SAC) and noise reduction coefficient (NRC) values. Findings show that the diameter of kenaf fiber gradually decreased with the increment of the NaOH concentration. The eliminations of the hemicellulose and lignin layer of the strands causing the decreased of the strand diameter which was proven by FTIR analysis. Results from SAC shows that treated Kenaf fiber using 6%, 7%, and 8% of NaOH obtained higher SAC at high frequency range (>2500 Hz). Those samples obtained 0.67 coefficients for their NRC value. This research concludes the sound absorption capabilities of kenaf absorber was better using thinner strands and the 6% NaOH concentration was the optimum concentration to treat kenaf fiber for sound absorber. [ABSTRACT FROM AUTHOR]

The main goal of this study is to assess the mechanical, physical and morphological properties of bundle fibers extracted from curaua leaves and pullout testing in cementitious matrix. The mechanical properties of the fibers were analyzed in mechanical testing of four fiber lengths (10, 20, 30 and 40 mm) to observe the influence of the length of the variable's tensile strength, Young's modulus and Weibull modulus. Pullout testing was measured frictional and maximal force. Fibers physical properties were assessed by means of the multipycnometer method. Morphological analyses were conducted through optical and scanning electron microscopes. The results showed that the fiber length does not interfere with the tensile strength (507–638 MPa) and Weilbull modulus (8–12). However, it influences the Young's modulus (19–39 GPa). Curaua bundles present a higher resistance to rupture and Young's modulus than other plant fibers species and it seems to be related to the distribution of faults along the beam. The fibers morphological characterization showed a rough and irregular surface with some impurities which are associated with the surface of the fibrous bundle and low adherence (0,26–0,47 N) with cementitious matrix in pullout testing. [ABSTRACT FROM AUTHOR]

This study investigated the physical, chemical, thermal, morphological, and XRD analysis of Symphirema involucratum stem fiber to establish its suitability in composite reinforcements. The investigation on chemical components proved that the fiber possesses a good amount of cellulose content (57.32%) with low lignin (13.85%), hemicellulose (12.47%), wax (0.56%), moisture (9.11%), and ash (9.05%) contents. The fiber showed a density of 1389 kg/m3, a diameter of 542.26 ± 10.32 µm, and a crystallinity index of 28.22%. Higher maximum degradation temperature (350°C) with a kinetic activation energy of 74.88 kJ/mol obtained by thermogravimetric analysis. Nuclear magnetic resonance spectra confirmed the presence of high cellulose content at the intensities of the C-2, C-3, and C-5 lines. The microscopic examination of the SISF through a scanning electron microscope and atomic force microscopy revealed that the fiber possesses quite a high coarse fracture surface with pores. The properties of the SISF propose its suitability toward use as an alternative to man-made synthetic fibers. [ABSTRACT FROM AUTHOR]

The application suitability of natural fibers is increased by the method of hybridization. The current study deals with the development and characterization of four different tri-layer composites by varying the stacking sequence of Parthenium hysterophorus and Impomea pes-caprae fibers with epoxy as a matrix, by using the conventional hand layup process. The mechanical properties, namely tensile, flexural, impact, Shore D hardness, and water absorption properties, were analyzed as per ASTM. The test results show that composites with upper layers of Impomea pes-caprae and a core layer of Parthenium hysterophorus fibers showed enhanced mechanical properties and reduced water absorption, thereby proving its suitability for lightweight medium load applications. Morphological studies using Scanning Electron Microscope elucidated the fiber bonding and void characteristics of the tested composites. [ABSTRACT FROM AUTHOR]