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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]

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]

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]

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]

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]

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]

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]

The present study aimed to investigate the effect of alkali (NaOH) treatment on the morphological properties and tensile strength of Yucca Gloriosa (YG) natural fibers along with the optimization of the parameters related to such treatment. The Response Surface Methodology (RSM) with Central Composite Designs (CCD) approach for the design and analysis of experiments with the optimization of NaOH concentration and immersion time was applied. Also, the Scanning Electron Microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were also employed to evaluate and compare the morphological and structural properties of YG fibers. For NaOH treatment process the best mathematical models to predict the fiber diameter and tensile strength of the YG fibers were the linear and quadratic models, respectively. Additionally, the optimal amount of YG fibers diameter and tensile strength were achieved at optimum process conditions. The optimized levels for NaOH concentration and immersion time were 5 wt.% and 10 h, respectively. So that, after fiber treatment in this condition, tensile strength of YG fibers was increased by 29.58% and the diameters of YG fibers were decreased by 7.34% compared to the raw fibers. Nonetheless, the process of alkali treatment in optimum conditions did not significantly affect the structural and crystallinity of YG fibers. Finally, NaOH treatment under optimal condition, mainly because of improving the morphological and tensile properties as well as increasing the interfacial adhesion between natural fibers and polymer matrices, is practically useful in the manufacture of multi-purpose hybrid composites. [ABSTRACT FROM AUTHOR]

This research investigates the combined effect of steel and natural fibre on the mechanical properties and spalling resistance of ultra-high performance concrete (UHPC) before and after exposure to elevated temperatures. The effects of two parameters, namely temperature (ambient temperature, 200 °C, 400 °C and 600 °C) and fibre type (solely macro end hooked steel fibre (MHS) and hybrid of micro straight steel fibre (MSS), macro end hooked steel (MHS) fibre and micro jute (MJ) fibre) on the mechanical properties, spalling resistance and mass loss of UHPC were studied. Micrographs from scanning electron microscope (SEM) test were utilized to appraise the steel fibre and jute fibre before and after exposure to elevated temperatures. The test results exhibited that the residual tensile strength and flexural strength were significantly declined after exposure to high temperatures for UHPC specimens reinforced with macro steel fibre only. Moreover, explosive thermal spalling occurred for this group of specimens under 600 °C. Whereas the combined use of jute fibre and micro-macro steel fibre was an effective approach to prevent the explosive thermal spalling under 600 °C and improve the residual tensile strength, flexural strength and toughness of UHPC. Furthermore, preliminary empirical expressions have been developed in this study to predict the residual mechanical properties of UHPC as a function of natural fibre content, steel fibre content and temperature. [ABSTRACT FROM AUTHOR]

Natural fiber reinforced hybrid polymer composites have gained extensive applications in recent decades owing to their damping, low density, biodegradability, and low‐cost benefits. This research explores the impact of the surface treatment, and the number of ramie fiber layers on the vibrational and mechanical characteristics of a glass/ramie fiber reinforced hybrid polymer composite. The composite is made of outer layer (glass fiber) and inner layer (ramie fiber) at different concentrations (varying between 2, 3, and 4). The ramie was pre‐treated with sodium hydroxide (NaOH) at different weight percentages (1%, 2%, and 5%). The composites have been fabricated using the vacuum bag technique. The composites have been characterized for chemical, mechanical, morphological, and free vibrational analysis. Fourier transform infrared spectroscopy and scanning electron microscope have been used to study the chemical characteristics and morphological study of the composites respectively. The mechanical properties of the composite were evaluated through tensile and flexural testing. The hybrid composite reinforced with two layers of ramie fiber as the core with 2% pre‐treated shows the maximum tensile strength of 120 MPa and flexural modulus of 12,147 MPa. Overall, the hybridization and NaOH pre‐treatment to certain ratio helps in increase in the hybrid composite's mechanical strength compared to the natural fiber composite. [ABSTRACT FROM AUTHOR]

The current investigation aims to choose an alternate potential replacement for the nonbiodegradable synthetic fibers used in polymer composites. This goal motivated the thorough characterization of Rosa hybrida bark (RHB) fibers. The research explored fiber characterization such as morphological, mechanical, thermal, and physical properties. The suggested fiber features a percentage of cellulose, hemicellulose molecules, and lignin of 52.99 wt%, 18.49 wt%, and 17.34 wt%, respectively according to chemical composition studies, which improves its mechanical properties. It is suitable for lightweight applications due to its decreased density (1.194 gcm−3). The purpose of the Fourier transform infrared spectroscope was to observe and record how various chemical groups were distributed throughout the surface of the fiber. The presence of 1.41 nm-sized crystalline cellulose and further XRD analysis showed a crystallinity index of 75.48 %. Scanning electron microscope studies revealed that RHB fibers have a rough surface. According to a single fiber tensile test, for gauge length (GL) 40 mm, Young's modulus and tensile strength of RHB fibers were 6.57 GPa and 352.01 MPa, respectively, and for GL 50 mm, 9.02 GPa and 311 MPa, respectively. Furthermore, thermo-gravimetric examination revealed that the isolated fibers were thermally stable up to 290 °C and the kinetic activation energy was found to be 75.32 kJ/mol. The fibers taken from the Rosa hybrida flower plants' bark exhibit qualities similar to those of currently used natural fibers, making them a highly promising replacement for synthetic fibers in polymer matrix composites. [ABSTRACT FROM AUTHOR]

• Energy absorption properties of coir fibers at different compression speeds. • Energy absorption properties of differently stacked coir fibers under compression. • Measuring the rate sensitivity of coir fiber. • Calculation of crushing efficiency from experimental results. • Scanning electron microscopy was taken to verify the results. Coir fiber, a natural plant fiber material, is known for its excellent shock absorption ability and potential to improve the performance of composite materials. This paper investigates the compression and energy absorption of coir fibers arranged horizontally and vertically at different speeds to determine their velocity sensitivity. A quasi-static compression speed test was conducted on coir fiber blocks using a universal testing machine. Load displacement changes were observed at speeds of 1 mm/Min, 2 mm/Min, 4 mm/Min, and 50 mm/Min, and Dynamic Increase Factor (DIF) was introduced to evaluate speed sensitivity. The microstructure of the fibers was evaluated using a scanning electron microscope (SEM). According to the results, vertical fibers have better energy absorption characteristics than horizontal fibers, resulting in an increased energy absorption effect ranging from 25.7 % to 45.38 %. On the other hand, horizontal fibers exhibit high sensitivity under low-speed compression, with a significant increase in energy-absorbing effect as speed increases. However, this sensitivity is significantly reduced when compression occurs at high speed. The energy-absorbing effect of horizontal fibers increases from 6.96 % to 33.58 %. Vertically placed fibers, on the other hand, exhibit low sensitivity under low-speed compression but greater sensitivity as speed increases. As speed increases, the energy absorption effect becomes more apparent, resulting in an increase in the energy absorption of vertical fibers from 12.88 % to 17.99 %. This paper presents a methodology for evaluating the compression properties of coir fibers, which can be used as a reference for studying the impact resistance of natural fibers. [ABSTRACT FROM AUTHOR]

• Natural bamboo fiber and basalt fiber were used to reinforce AAC. • The effect of fiber content and fiber length on the properties of AAC was tested. • The slurry fluidity, gas-foaming curve, mechanical properties, thermal conductivity and microstructure of sample were examined. • Natural bamboo fiber AAC had better mechanical performance than basalt fiber AAC, but its thermal conductivity was larger. Autoclaved aerated concrete (AAC) has the advantages of low density and good thermal insulation performance, but its mechanical properties are not so good. In this experiment, natural bamboo fiber and basalt fiber were used to strengthen AAC, and the effect of fiber content and fiber length on the AAC properties was investigated. The experimental results showed that with the increase of fiber content, the slurry fluidity, foaming height of AAC mixture decreased, the area of hazardous pore, the density, mechanical strength and thermal conductivity of AAC increased. As the fiber length increased, similar results were observed in the mechanical strength and thermal conductivity of AAC but not found in the slurry fluidity, foaming curve and pore structure. By contrast, natural bamboo fiber had greater impact on the properties of AAC than basalt fiber. The scanning electron microscope (SEM) results showed natural bamboo did not react with AAC matrix and the fiber was pulled out from AAC matrix when the AAC cracked, while basalt fiber was corroded in alkaline matrix and broke with AAC matrix together under external load. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the hygrothermal and mechanical properties of innovative mortar mixtures reinforced with natural fibers. Fibers extracted from palm stems (PS) and hemp (HF) were evaluated at different percentages. Scanning electron microscope (SEM) observations showed that the PS fibers have rough surfaces and very complex microstructures. Prior to their incorporation into the mortar, the fibers were subjected to different treatments to reduce their hydrophilic character. The employed treatments showed good efficiency in reducing the water absorption of both PS and HF fiber types. Furthermore, the mortar mixtures incorporating these fibers exhibited low thermal conductivity and excellent moisture buffering capacity. Indeed, the moisture buffer value (MBV) of the investigated mixtures ranged between 2.7 [g/(%HR·m2)] and 3.1 [g/(%HR·m2)], hence providing them excellent moisture regulator character. As expected, the fiber mortar mixtures showed very high porosity and low compressive strength ranging between 0.6 and 0.9 MPa after 28 days of age. The low-environmental footprint materials developed in this study are intended for thermal insulation and building filling. [ABSTRACT FROM AUTHOR]

In the last decades, researchers have developed new materials to improve the quality of human life. Owing to the frequent occurrence of bone fractures, it is important to develop plate materials for the fixation of fractured bones. These plate materials have to be lightweight, compatible with human tissues and ought to allow stiffness. Natural fibers have the advantage that they are renewable resources and have marketing appeal. The Asian markets have been supplying natural fibers for many years, e.g., sisal, banana and roselle are common reinforcement in India. In this research, the fabrication of plate material from powdered natural fibers like sisal (Agave sisalana), banana (Musa sapientum) and roselle (Hibiscus sabdariffa), with bio-epoxy resin Grade 3554A and Hardner 3554B, using moulding method, is described. The present work deals with the prediction of flexural rigidity of the NFRP composite which is compared with that obtained using the ANSYS solution. They are found to be in good agreement. In this work, microstructure is scanned by the scanning electron microscope. The objective of this research was to utilize the advantages offered by renewable resources for the development of biocomposite materials based on biopolymers and natural fibers. In the future, this plate material externally coated with calcium phosphate and hydroxyapatite (hybrid) composite can be used for inside fixation and also external fixation of fractured bones. [ABSTRACT FROM AUTHOR]

The study investigated the effectiveness of the combination of chemical and physical methods of natural fibers' modification. The long flax fibers were subjected to various types of modification. These were silanization, plasma modification and a combination of these methods. For the silanization process, two types of silanes were used: amino- and vinylsilane. The application of structurally different compounds allowed us to acquire knowledge about the effect of the modifier structure on its properties. Various properties of flax fibers were investigated, comparing the results before and after different modification processes. The flammability of prepared samples were tested by pyrolysis combustion flow calorimeter (PCFC). In the effect of the natural fibers' modifications, flammability was reduced even by 30%. The thermal stability of modified fibers increased. The FTIR tests of the gases released during thermal degradation of the tested fibers allowed us to determine the important compounds and prove a lower degree of flax-fiber decomposition after modification. Flax fibers were also tested to evaluate their physical properties (linear mass, average diameter, aspect ratio and hygroscopicity). Changes in surface morphology were observed by scanning electron microscope (SEM). The properties of natural fibers improved significantly, thus contributing to an increase in their suitability for the use in composites. [ABSTRACT FROM AUTHOR]

This study assessed the impact of alkali treatment of hemp and flax fibers on mechanical properties (determined by means of the uniaxial tensile test, impact tensile strength test and hardness test), processing properties (the course of the extrusion and injection process) and usable properties (shrinkage of molded pieces, degree of water absorption) of biocomposites on the base of poly (3-hydroxybutyric-co-3-hydroxyvaleric acid) (PHBV) biopolymer. For this purpose, 1 mm of length flax and hemp fibers was surface-modified by means of aqueous solution of NaOH (sodium hydroxide) with concentrations of 2%, 5% and 10%. The composites were made using the extrusion technology. The test specimens were produced by injection molding technology. In total, eight types of biocomposites with modified and non-modified fibers were produced, and each biocomposite contained the same filler content (15 wt.%). Their properties were compared in some cases with pure PHBV polymer. In the case of biocomposites filled with hemp fibers, it was noted that an increase of the alkalizing solution concentration improved most of the tested properties of the obtained biocomposites. On the other hand, in the case of flax fibers, there was a significant decrease in most of the mechanical properties tested for the composite containing fibers etched by 10% NaOH solution. The obtained results were verified by examining fibers and the destroyed specimens with a scanning electron microscope (SEM) and an optical microscope, which confirmed, especially, the significant geometry changes of the flax fibers etched by 10% NaOH solution. This procedure also resulted in a significant change of processing properties—a composite of this fiber type required about 20 °C lower temperature during the extrusion and injection molding process in order to obtain the right product. These results lead to the important conclusion that for each filler of the plant-origin and polymer matrix, the fiber alkalization method should be selected individually in order to improve the specific properties of biocomposites. [ABSTRACT FROM AUTHOR]

Nowadays the use of natural fiber composites has gained significant interest due to their low density, high availability, and low cost. The present study explores the development of sustainable 3D printing filaments based on rice husk (RH), an agricultural residue, and recycled polypropylene (rPP) and the influence of fiber weight ratio on physical, thermal, mechanical, and morphological properties of 3D printing parts. Thermogravimetric analysis revealed that the composite's degradation process started earlier than for the neat rPP due to the lignocellulosic fiber components. Mechanical tests showed that tensile strength increased when using a raster angle of 0° than specimens printed at 90°, due to the weaker inter-layer bonding compared to in-layer. Furthermore, inter layer bonding tensile strength was similar for all tested materials. Scanning electron microscope (SEM) images revealed the limited interaction between the untreated fiber and matrix, which led to reduced tensile properties. However, during the printing process, composites presented lower warping than printed neat rPP. Thus, 3D printable ecofriendly natural fiber composite filaments with low density and low cost can be developed and used for 3D printing applications, contributing to reduce the impact of plastic and agricultural waste. [ABSTRACT FROM AUTHOR]

In this paper, the areca fiber was extracted by physical and chemical treatment, and then the areca fiber/natural latex composite was prepared by natural latex impregnation technology. In order to combine areca fiber and natural rubber latex better, three silane coupling agents with different action mechanism were selected: Si−69, KH550, and KH570 which were used to treat the areca fiber/natural latex compound. The results show that the silane coupling agent can change the surface of the fiber from hydrophilic surface to organophilic surface, making the bonding of areca fiber to natural latex more closely. At the same time, the mechanical properties, physical and mechanical properties, swelling properties, and dynamic viscoelastic properties of the tightly bonded areca fiber/nature latex composites were improved. After observing the micro-structure through a scanning electron microscope, it was found that the three silane coupling agents could effectively bind areca fiber and natural latex to enhance the performance of the composite material, of which Si−69 performed best, and the tensile strength and tear strength of the composite increased by 21.19% and 12.90% respectively. [ABSTRACT FROM AUTHOR]

Recently, the importance of environmental issues has made scholars to focus on the implementation of bio-degradable resources in different applications. The same trend is being followed in adhesives improvement by adding different bio friendly materials. In this study, the possibility of implementation of natural resources obtained from annual pruning of date palm tree is investigated by considering the effects of fiber treatment, fiber length and fiber density on the mechanical properties of structural adhesives in an empirical way using a considerable amount of experimental work. In this journey, first the tensile strength of different types of fibers, in raw and treated conditions is compared and the morphology of fibers surface is examined. Then, the effects of type, length, weight ratio and treatment conditions on the tensile strength improvement of different adhesives are investigated. The results demonstrate the success of implementation of the aforementioned bio friendly fibers in this application. In some cases, the increase in strength even exceeds 64%. Moreover, a higher fiber length results in higher increase in strength while the strengthening effect diminishes as the fiber weight ratio surpasses a certain value. Using scanning electron microscope technique, the effect of treatment on fiber surfaces is also analyzed. [ABSTRACT FROM AUTHOR]