Natural Fiber Composites Research Articles

Development of eco-friendly bio-composites using banana fibers for enhanced tensile and flexural properties

The synthetic fiber composite materials have witnessed widespread adoption in high-performance applications due to their lightweight and high-strength properties. However, the non-renewable and non-biodegradable nature of synthetic fibers has raised environmental concerns. This has spurred research into natural fiber composites, often referred to as “bio-composites,” as sustainable alternatives to synthetic counterparts. Among these, bio-composites reinforced with natural fibers include banana, coir, jute, silk, sisal, and bamboo have gained significant attention as industrial materials. This research endeavor focuses on the development of banana fiber-reinforced composites using hand lay-up and VARTM methods techniques and explores their mechanical properties. Three distinct types of composites were fabricated, employing natural banana fibers and banana fabric as reinforcement materials, with epoxy resin as the matrix. Mechanical characterization encompassing tensile and flexural properties was conducted to assess the performance of the bio-composites. SEM with EDS analysis revealed distinct microstructural features and elemental compositions. The bio-composites manufactured via the VARTM method employing banana fabrics exhibited significant enhancements in mechanical properties. The bio-composites made with VARTM showed an impressive 160 % improvement inflexural strength and a 217 % increase in tensile strength when compared to the hand-layup method. The findings of this experimental study underscore the superior load-carrying capacity of bio-composites fabricated through the VARTM method and banana fabric reinforcement when compared to other combinations. This research underscores the potential of banana fibers as a sustainable alternative to synthetic fibers in composite materials, contributing to eco-friendly and environmentally responsible solutions in various high-performance industries

Harnessing the potential of Pseudoxytenanthera bamboo rhizome for enhanced high-friction assistive solutions

Bamboo cultivation has surged globally, yet environmental concerns arise due to the invasive nature of bamboo rhizomes, often overlooked in favour of shoots. Despite being a renewable resource with rapid growth, rhizomes are underutilized in engineering due to their limited tensile strength from short fibers and hydroxyl group presence. This study explores the untapped potential of Pseudoxytenanthera stocksii (P. stocksii) [Syn. Dendrocalamus stocksii] rhizomes (PSR), enhancing their engineering properties by chemically treating and displacing hydroxyl groups to mitigate their hydrophobic nature. Utilizing the inherent compressive strength of bamboo, treated P. stocksii rhizomes are employed in fabricating composites through hot compression molding, tailored for high-friction assistive applications. Comprehensive analyses, including physical, chemical, and tribological assessments, evaluate PSR for high-friction scenarios, benchmarking them against culm composites and other natural fibers. Results indicate that benzoylated P. stocksii rhizome composites (BPSRC) exhibit properties comparable to, and in some cases surpass, many natural fibre composites. Superior thermal adaptability, revealed through thermogravimetric analysis, positions BPSRC as an eco-friendly alternative to conventional natural fibre composites. Tribological tests underscore the adaptability of PSR composites for high-friction assistive applications, presenting a promising avenue for sustainable bamboo utilization and environmentally conscious engineering solutions.

Analysis of Water Migration and Spoil Slope Stability under the Coupled Effects of Rainfall and Root Reinforcement Based on the Unsaturated Soil Theory

Root reinforcement is an effective slope protection measure due to root water absorption and soil suction. However, the coupled effect of rainfall and root reinforcement remains unclear, resulting in a challenge to evaluate slope stability in complex environments. This paper regards the root–soil composite as a natural fiber composite and quantifies its reinforcement effect using direct shear tests. The unsaturated soil seepage–stress theory was employed to simulate the effect of rainfall on water migration and the stability of spoil, overburden, and vegetated slopes. Field measurements and pore water pressure tests verified the simulation results. Furthermore, the influences of the slope angle, rainfall parameters, and vegetation cover thickness on slope stability were analyzed. The results showed the following: (1) The root reinforcement enhanced the soil’s ability to resist shear deformation, substantially improving soil shear strength. The cohesion of the root–soil composite (crs = 33.25 kPa) was 177% higher than that of the engineering spoil (ces = 12 kPa) and 32.21% higher than that of the overburden soil (cos = 25.15 kPa). (2) The overburden and vegetated slopes had lower permeability coefficients and a higher shear strength than the spoil slope, and the effect was more pronounced for the latter, resulting in lower landslide risks. The water migration trend of the vegetated slope was characterized by substantial runoff and a low sediment yield. The safety factors of the spoil slope, overburden slope, and vegetated slope were 1.741, 1.763, and 1.784 before rainfall and 1.687, 1.720, and 1.763 after rainfall, respectively, indicating a significantly higher safety factor of the vegetated slope after rainfall. (3) The slope angle significantly affected slope stability, with lower safety factors observed for higher rainfall intensities and durations. Under these conditions, the slope angle should be less than 30°, and the soil thickness should be 0.5 m for herbaceous vegetation and shrubs and 1.0 m for trees.

Sandwich structures of aluminium skins and egg-box-shaped cores made with biobased foam and composites

Sandwich panels composed of aluminium skins and egg-box-shaped cores made with natural fibre composites are tested in three-point bending and evaluated statistically and through failure analysis. The corrugated cores are assessed with filled bio-based foam. In order to produce these sandwich panels, preliminary investigations on natural fibre composites, and their use as egg-box-shaped structures are conducted. A full factorial design is performed to assess the effects of fibre reinforcement (sisal or coir) and polymer matrix types (epoxy or castor oil) on the physical-mechanical properties of flat composite laminates. These composites are also used to manufacture the egg-box shaped structures in different sizes, which are characterized under compression testing. A new analytical approach called RJS Method is used to determine the flexural and shear modulus of the proposed sandwich panels and estimate the shear contribution. The results reveal that flat laminated composites and their corresponding egg-box shaped cores, composed of sisal fibres and epoxy polymer, achieve higher absolute and specific mechanical properties. The corrugated core also leads to sandwich panels with higher mechanical properties, increasing the skin and core shear stresses by up to 60 and 76%, respectively, compared to the coir fibre castor-oil cores. The failure modes of the sandwich panels are limited to the core and are chronologically established through foam tearing, foam-egg-box shaped composite debonding, and final egg-box cell-wall flattening. The findings demonstrate that the sandwich panel based on egg-box shaped core made from natural resources is feasible for scaling up in different structural applications.

Properties of kenaf fiber-reinforced polyamide 6 composites

Abstract Despite the increasing interest in polyamide-based composites, few studies on polyamide-based natural fiber composites have been conducted due to their high melting temperatures of polyamide 6 (PA6). In this study, kenaf fiber-reinforced polyamide 6 composites (KF/PA6) were successfully prepared and their properties were investigated. Thermogravimetric analysis demonstrated that the neat PA6 has higher thermal stability with higher melting temperatures of 426°C, respectively, than KF/PA6 composites. The results of the differential scanning calorimeter showed that the glass transition temperature (T g) of KF/PA6 composites was slightly shifted to a higher temperature at 59°C than that of the neat PA6 at 45°C. The thermal and mechanical characteristics using dynamic mechanical analysis results showed that the storage and loss modulus of the neat PA6 were higher than those of KF/PA6 composites. The neat PA6 showed the maximum tensile strength of 48 MPa; however, the maximum tensile modulus was obtained at 10 wt% KF with 2,100 MPa. The flexural strength and modulus of the neat PA6 were 91 and 2,506 MPa, respectively, which were higher than those of KF/PA6 composites. The impact strength also deteriorated with the addition of KF, from 3.72 to 1.91 kJ·m−2. Voids, fiber pulled-out, and agglomeration were observed in scanning electron microscope analysis on the tensile fractured surfaces.

Ultrasonication‐assisted alkali treatment of hemp fibers to improve the fiber/matrix interface of hemp/epoxy composites: The influence of sodium dodecyl sulfate surfactant

AbstractAlkali pretreatment of fibers is an efficient technique to enhance fiber/matrix bonding in natural fiber composites. This study investigates if the addition of sodium dodecyl sulfate (SDS) surfactant increases the efficacy of alkali treatment of hemp fibers. SDS concentrations ranging between 2 and 10% wt/wt were used with a constant (10% wt/wt) NaOH concentration. Fiber surfaces were observed with scanning electron microscopy (SEM). Fiber surfaces were cleaner when SDS was used compared with alkali treatment with no SDS added indicating the elimination of substances such as lignin, waxes, hemicelluloses, and pectin. Fourier‐transform infrared spectroscopy and TGA studies also confirmed the removal of these substituents. Mechanical performance of the composites was evaluated via static and dynamic tests. The tensile strength and modulus improved 24.9% and 13.6% respectively with the addition of 10 wt% SDS. The flexural strength and modulus also showed an improvement of 22.4% and 26.3% respectively when 10 wt% SDS was added to alkali solution. Dynamic mechanical tests showed that the storage and loss modulus of the composites increase with SDS/alkali treatment. Results indicated that the use of SDS in alkali treatment notably improves the composite performance which is attributable to more efficient elimination of noncellulosic constituents from fiber structure.Highlights Sodium dodecyl sulfate (SDS) improves the efficacy of NaOH treatment of hemp. Removal of noncellulosic substances from fibers was facilitated by SDS. Ultrasound/SDS assisted alkalization of fibers improved composite properties.

A review on natural fiber composites: Polymer matrices, fiber surface treatments, fabrication methods, properties, and applications

AbstractHigh performance and durability are essential for goods to satisfy the needs of the expanding worldwide market. Wood plastic composites (WPCs) are materials made from a combination of wood, polymers, and additives. WPCs can be extruded, injected, compressed, or thermoformed. Presently, WPCs are manufactured using sophisticated processes including as laser sintering, fused layer modeling, and additive manufacturing. Properly managing the melt temperature and pressure is crucial in the manufacturing process of WPCs to ensure effective polymer incorporation. Natural fibers have distinct benefits for polymer composites, but they also have some serious drawbacks, like lower strength properties—especially lower impact strength than synthetic fibers—poor compatibility with hydrophobic polymers, poorer dimensional stability and moisture absorption due to hydroxly groups, a maximum processing temperature that is limited, thermal degradation above 200–220°C, and lower biological durability. The modification of the surface of the fibers improves the mentioned disadvantages of the natural fibers. High‐quality WPCs require the application of chemical or physical treatment to the wood fibers. This extensive review focused on the modification techniques applied to the surface of wood, manufacturing processes, and properties and applications of WPCs.Highlights Modification methods used in surface treatment of natural fibers was explained. Properties and recent applications of wood polymer composites were given. Optimum requirements of natural fibers and polymer matrices are given. Fabrication methods of natural fiber composites are extensively given.

An experimental review on enhancing the low and high-velocity impact resistance of NFCs through nanoparticle reinforcement

Nanoparticles are widely used in biocomposite materials due to their ability to improve the mechanical properties of composites. This comprehensive review analyzes the use of nanoparticles to enhance the experimental low and high-velocity impact resistance of natural fiber composites. Various nanoparticles like carbon nanofibers, carbon nanotubes, boron nitride, zinc oxide, and titanium dioxide were investigated as reinforcements at different loading levels. The addition of nano-ZrO2 alone or with graphene oxide yielded the highest impact resistance and interlaminar shear strength of basalt fiber/epoxy composites. Cloisite 20A clay improved the mechanical properties of an epoxy matrix. Carbon/epoxy laminates showed improved maximum impact force, energy absorption, and displacement with 2wt% carbon nanofibers loading. Nanoparticles were found to enhance moisture and temperature resistance by strengthening the fiber–matrix interface. The literature demonstrated that small amounts of well-dispersed nanoparticles can meaningfully improve natural fiber composites’ impact resistance, strength, stiffness, toughness, and energy absorption through mechanisms like crack arresting and bridging. Hybrid carbon-basalt fibers and calcium carbonate nanoparticles also enhanced composite performance. Balancing the nanoparticle loading is crucial to prevent agglomeration effects. Future studies on their toxicity and environmental impacts would be needed for widespread commercial applications of Biocomposites.

Appraising the microstructure and electrical conductivity characteristics of polyaniline-coated natural fiber composites

Appraising the microstructure and electrical conductivity characteristics of polyaniline-coated natural fiber composites

Exploring the development and applications of sustainable natural fiber composites: A review from a nanoscale perspective

As a result of global sustainable development, natural fiber composites (NFCs) have become increasingly attractive due to their remarkable performance, novel functionality, and eco-friendliness. Natural fibers are biodegradable, affordable, and low-density, which makes them potential materials for use in developing alternatives to traditional petroleum-based synthetic fiber composites. However, challenges such as inadequate compatibility between natural fibers and matrix limit the further development of NFCs. Studies have shown that molecular dynamics (MD) simulations can offer valuable insights into the fundamental properties and deformation mechanisms governing the macroscopic performances of NFCs, including mechanical properties, thermal stability, and interfacial interactions. Based on the underlying understanding of the nanostructure of natural fibers, these fibers can be modified at nanoscale to improve the performance of NFCs. This paper first reviews the hierarchical structures of natural fibers, mainly wood and bamboo fibers, highlighting their relationship with mechanical and thermal properties. Treatments to improve natural fiber-matrix compatibilities are then presented. The fundamental factors behind the functionalized properties of modified NFCs are emphasized from the nanoscale. Additionally, applications of NFCs as structural and functional materials in the construction, automotive, and aerospace industries are reviewed. Finally, this paper identifies the growing use of machine learning-assisted MD simulation techniques to facilitate the design of NFCs. Literature and data sources for this study were obtained through a combination of online academic databases, citation chaining, government databases, and industry reports.

Long coir and glass fiber reinforced polypropylene hybrid composites prepared via wet-laid technique

Natural fiber composites offer an advantage in terms of weight saving for many automotive applications; however, many natural fiber composites lack properties to justify substitution for synthetic composites. Hybridizing the natural fiber composites by adding a fraction of synthetic fibers is an innovative approach to provide a balance between composite's performance and weight savings. In this study, coir fiber (40 wt%)-reinforced polypropylene (PP) composites were hybridized by substituting a fraction of coir fiber with glass fiber (0–30 wt%). The composites were prepared using a novel wet-laid technique followed by compression molding, where the fiber length is preserved. The composites prepared by hybridizing PP/coir fibers with glass fibers were light in weight (6–20% lighter compared to 40 wt% glass fiber reinforced PP) with significantly enhanced tensile (strength – 49–182%, modulus – 54–130%), flexural (strength – 41–104%, modulus – 64–193%), and impact properties (157 - 474%) compared to 40 wt% coir fiber reinforced PP composites. Furthermore, the addition of glass fiber (10–30 wt%) to coir fiber reduced the water-absorbing tendency (by 18–74%) of PP/coir fiber composites. All in all, this work has potential applications in automotive, mass transit, and truck applications where natural fiber composites are being investigated as alternatives to metal and/or fully synthetic composites.

Effect of elastomeric filler content on the acoustic and mechanical response of natural fiber-based hybrid composites

The environmental threat of discarded tires needs to be addressed through alternative applications with the enormous increase in the global vehicle population. When tire rubber particles are combined with environmentally friendly, and biodegradable natural fibers in polymer composites, such materials have a lot of potential for use in a variety of applications of insulating structures. The current work explores the effect of adding waste tire rubber particles (TRP) to natural fiber-based hybrid composites, on mechanical and acoustic properties and investigate the possibility of a potential insulating structural material. Tire rubber particles were employed as fillers and chopped banana fibers as reinforcing fibers (particle size less than 400 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}m) with epoxy resin as the matrix in this work. Five compositions were formulated in which the TRP content was varied from 0 to 36 wt.%, compensating for the fiber wt.%. The different compositions prepared by compression molding technique were subjected to compressive, impact, and acoustic characterization. In the natural fiber composites, the compressive strength was observed to dip with increase in TRP content while impact strength was found to rise till 15 wt.% TRP content. Beyond 15 wt.% TRP fillers, the impact strength and brittleness declined. The optimal acoustic response in terms of the sound transmission loss was observed for the composition with 15 wt.% TRP fillers. Polymer composites with natural fiber reinforcing and elastomeric fillers create excellent interior lining materials for buildings, automobiles, and aircrafts, because of their superior mechanical properties and acoustic proofing.

Impact of flax fibre micro-structural features on composite damage observed through micro-CT characterisation

To exploit the potential of flax fibres in reinforcing polymers, the performance of flax fibres must first be understood and then optimized. In this context, this paper aims to provide a visual and comprehensive description of the impact flax fibre micro-structural features, such as kink bands, porosity and cortical residues, have on damage evolution during tensile loading of Polylactic acid (PLA) matrix composites reinforced by flax fibres. In-situ synchrotron radiation computed tomography (SRCT) has been used for 3D visualisation of microstructural evolution at stress levels between 10% and 90% of the ultimate failure stress. First, the main defects of the overall microstructure are described, including a quantitative analysis of porosities. Then, novel visual insights, highlighting the main role of kink-bands in fibre failure and subsequent composite breakage, are described. Interestingly, it appears that for the flax/PLA composite studied, kink-band inter-distances are consistently smaller than critical fibre lengths, explaining the likelihood of rupture in kink-band regions. These findings demonstrate that fibre extraction and subsequent textile reinforcement manufacturing are critical steps and should be optimised to increase the performances of natural fibre composites.

Experimental investigation of layering pattern arrangements on mechanical, swilling and water absorption behavior of flax/coir fiber based bio-epoxy composites

As natural fibres are recyclable and biodegradable, they are essential to the creation of ecologically sound composite materials. When compared to synthetic fibres, they have benefits including less environmental impact, superior mechanical qualities, and a lightweight nature. Gaining knowledge about and improving the usage of natural fibres in composites can result in environmentally friendly solutions that have a lower carbon footprint and more durability across a range of uses. The present research concentrates on the manufacture of hybridized bio-composites with eco-friendly epoxy as the matrix phase and flax as well as coir fibre mats as reinforcing agents. The hybridized composites of flax (F) and coir (C) fibres were created using a low-cost manual lay-up approach, accompanied by a hot press containing various stacking sequences. The materials' static characteristics, like inter-laminar shear strengths (ILSS) as well as hardness, were investigated. Physical parameters like water absorption and swelling thickness were also investigated. The experimental findings demonstrate that whenever the layering pattern was changed, bio-composites displayed small variations in strength properties. The FFFF sample had the greatest ILSS result of 7.69 MPa. Short beam breakdowns feature such as perpendicular inter-laminar shear fractures, micro buckling, and fibre breakage have also been observed. Although there were some advantages in the mechanical properties of bio-composites over eco-friendly epoxy, there were no significant consequences for modifying the toughness characteristics of a fibre sheet's cross-ply. This might be attributed to the low interaction of coir and flax strands, in addition to the hybrid composite specimens' poor interfacial bonding and strength. In comparison to their hybrid equivalents, pure fibre or non-hybrid materials demonstrated greater resilience to water uptake as well as thickness swelling.

Durability of hybrid flax fibre-reinforced epoxy composites with graphene in hygrothermal environment

Natural fibre composites are highly sensitive to the hygrothermal environment (humidity and elevated in-service temperature). Enhancing the long-term behaviour of such composites can be achieved through additive manufacturing using nanomaterials as a constituent. Thus, this study investigated the mechanical properties of hybrid flax fibre-reinforced epoxy composites with 0%, 0.5%, 1% and 1.5% of graphene nanoparticles after exposure to a relative humidity of 98% for 1000, 2000, and 3000 hours and at temperature of 20°C, 40°C, and 60°C. The degradation behaviour of hybrid natural fibre composites was then evaluated by flexural and inter-laminar shear tests. Hygrothermal conditioning simulation of these hybrid composites was then performed using Arrhenius model based on accelerated aging data. The results of this study showed that graphene nanoparticles played a significant role in the reduction of moisture absorption and in the improvement of mechanical properties after hygrothermal conditioning. Compared to the specimens without graphene nanoparticles, the flexural and interlaminar shear strength in hybrid composites with 0.5%, 1.0%, and 1.5% graphene increased by 77.7%, 72.0%, and 77.1%, respectively, and up to 75.5%, 70.6%, and 73.5%, respectively after exposure for 3000 hours at 40°C. However, the degradation of the hybrid composites increased with the increase of conditioning temperature and exposure duration due to the moisture diffusion into the flax fibres and resin plasticisation. Nevertheless, the 0.5% graphene nanoparticles were found optimal in retaining the mechanical properties of aged hybrid composites due to their better distribution within the matrix. Accelerated test results showed that the hybrid composites can retain at least 57% and 49% of its flexural and interlaminar shear strength, respectively, after 100 years in service in hygrothermal environment at a temperature of 30°C representing the average annual temperature in Australia.

Sisal and jute composite containing carbon nanotubes for improved mechanical and thermal performance

Natural fiber composites are often sought after in industries, such as automotive and aerospace, due to their low density compared to traditional synthetic composites. Sisal and jute are renewable and biodegradable resources, making them attractive from a sustainability standpoint. The effect of carbon nanotube (CNT) insertion of a composed sisal and jute fiber composite material on the thermal and mechanical characteristics is investigated in this study. The primary objective of this research is to determine the exceptional mechanical strength and heat resistance that allows the composite-filled filling CNT to perform better than others. The methodical experimental approach was used to evaluate the effect of sisal and jute matrix and different amounts of CNTs’ mechanical and thermal properties. Thermal behavior is found by thermogravimetric analysis, and mechanical performance is used to qualify tensile strength, flexural strength, and impact resistance. The result suggests that CNTs may have reinforcing properties and significant tensile and flexural strength improvement. Impact resistance improved and increased the toughness of the composite material. The 7% CNT composite exhibited improvements in tensile strength of 63.9% and flexural strength of 46.6%, suggesting the synergistic reinforcing effect of CNTs. The high temperature from the use of need resistance shows promise for the composite material based on the tests of its capability for heat absorption and thermal stability. Various technical contexts are potentially useful in focusing on environmentally friendly material creation that exhibits exceptional thermal and mechanical properties.

Extraction of cellulose from soybean hulls for the development of polymer matrix composites with fishtail palm fibers

This study aims to extract and characterize cellulose nanocrystals (CNCs) from soybean hulls, and investigate their application as reinforcement in fishtail palm leaf stalk fiber (FPLSF) composites. CNCs were extracted through a multistep process involving alkalization, bleaching, acid hydrolysis and mechanical fibrillation. Analysis confirmed the transformation of cellulose I to cellulose II, yielding nanocrystals with 70.58% crystallinity index and thermal degradation peak at 371 °C. FTIR analysis verified removal of lignin and hemicellulose after extraction. The extracted CNCs were incorporated into FPLSF-epoxy composites at 2.5-10 wt% loading. Results showed 7.5 wt% CNCs (FT/SH4) provided optimal mechanical properties, with 51.4 MPa tensile strength, 46.09 MPa flexural strength and 36.47 kJ mm−2 impact strength. Lower CNC percentages showed significantly inferior properties due to poor fiber-matrix interfacial bonding. Overall, extracted soybean hull CNCs demonstrated good reinforcement capabilities for natural fiber composites. This provides a sustainable application route for agricultural residues and contributes to the development of high-performance biocomposites.

Mechanical and ballistic performance of ramie fiber-reinforced polymer composites: A review

Natural fiber composites (NFCs) have seen an increased innovation and research activities due to their strength, environmental impact, and low cost. NFCs are used in aerospace, construction, leisure, packing, sport, and automotive industries. One such NFC, ramie fiber-reinforced composite has gained more importance due to its high mechanical strength, stiffness, and easy availability to all other natural fibers. In this review, an insight of the research works focusing on ramie fiber, and its reinforced polymer composite has been summarized. Factors such as fiber content, surface treatment, manufacturing techniques, and coupling agents influencing the mechanical properties (tensile, flexural, and impact) have been summarized. It is evident that the surface modification of ramie fiber through chemical treatment and the addition of coupling agents directly impact the mechanical properties of the composite. Furthermore, the usage of ramie fiber composite is still inadequate due to its poor fire and moisture-resistant properties.

The Effect of Volume Fraction and Alkalization Treatment on Characteristic of Straw-Epoxy Hydrophobic Composites with Coating Method

The rapid development of the timber industry has caused the total capacity of the Indonesian timber industry to exceed the ability of production forests to provide raw materials sustainably. One of the industries that require a supply of wood as its main raw material is the furniture industry. The raw materials for furniture that are commonly used are logs and planks. In recent years, there has been the development of new materials that use natural fibers as polymer reinforcement, which can be used to replace wood materials. The material is a natural fiber composite. Composite materials reinforced with natural fibers are widely used in aerospace, automotive, circuit boards and other applications. One of the natural fibers that can be used as a composite is straw fiber. This high proportion of cellulose in straw fiber can be used for several things, one of which is composite materials. The utilization of rice straw fiber and epoxy as raw materials for making composites is an alternative to overcoming the increasing demand for wood. The purpose of this study was to determine and analyze the effect of volume fraction and alkalization treatment on the physical and mechanical characteristics of straw fiber composites, also to determine and analyze the effect of adding a coating of PE/SiO2 on the hydrophobic characteristics of straw fiber composites. The physical and mechanical properties of the composites were evaluated based on the SNI 03-2059-2006 and SNI-01-4449-2006 standard. The volume fractions used are 40%, 50%, and 60%. The length of the fiber used is 5 mm. And the alkalization variables used were 5% and 10% NaOH with 4 and 8 hours of immersion. The compressive strength decreased by adding fiber volume fraction and increased by higher treatment alkalization. The coating method can produce composite with the contact angle value of more than 90o.

Hemp fibers as sustainable reinforcement in natural fiber composites: A comprehensive review

Cannabis sativa, sometimes known as industrial hemp, is frequently used for manufacturing of high-cellulose bast (highly fibrous) fibers. The need for environmental conservation, combined with the beneficial characteristics of these fibers like their low thickness, high definite forte, and toughness prompts a strong interest in their utilization. Additionally, a great deal of effort has been put into developing novel materials thus improves the mechanical performance through surface modifications. Hemp fibers' most promising uses involve hybridization or as reinforcement in polymeric composites. However, more research is required to enhance their properties and broaden the scope of their uses. In the context of long-lasting applications and the ability to consistently reproduce the desired qualities of these composites, one significant concern is the biodegradability aspect, which requires careful consideration. This review offers a comprehensive examination of the existing body of research on hemp fibers, encompassing aspects such as the mechanical as well as chemical properties of hemp fibers, surface enhancements, hybrid composite materials, and both current and prospective applications.