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Poly(butylene‐adipate‐co‐terephthalate) (PBAT)/Kenaf fiber composites was prepared by the melt processing technique with various compositions to investigate the general properties. While the Young's modulus of the composite was profoundly improved, the tensile strength and elongation at break exhibited a significant diminished with the incorporation of kenaf fibers due to the poor interfacial adhesion between PBAT and Kenaf fibers. The Halpin‐Tsai model was applied, and the similar behavior of Young's modulus for the composite as compared to experimental results was calculated. The micro‐voids and cavitation were clearly confirmed by morphological observation. Reactive compatibilization with HDI improved the compatibility between PBAT and Kenaf fibers, and the mechanical performance was significantly enhanced due to improved interfacial adhesion. The PBAT/Kenaf composites with a reactive compatibilization showed considerable improvement of storage modulus, G′ in terminal region as well. The stable thermal stability could be also beneficial for thermal processing technique. The addition of Kenaf fiber resulted in a liquid‐like behavior decreasing elasticity of the PBAT/Kenaf composites. The HDI had a profound effect on increasing elasticity with solid‐like behavior resulting in enhancing the G′ and η* of the PBAT/Kenaf fiber composites due to the improved interfacial adhesion as confirmed from the morphological observation. Highlights: Kenaf fiber has a great effect on improvement of the modulus for PBAT/Kenaf compositesThe optimized PBAT/Kenaf composite composition is 96/4 wt% ratio for the compositeHDI is found to be a good compatibilizer for PBAT and Kenaf fiberReactive compatibilization enhances the interfacial adhesion between PBAT and Kenaf fiberThe compatibilized PBAT/Kenaf composites have the better mechanical performance [ABSTRACT FROM AUTHOR]

This study investigated the effect of various stacking sequences on the mechanical and acoustic characteristics of hemp and kenaf fibers reinforced hybrid composites. The mechanical study was done by using universal testing machine and izod imact tester. Further, acoustic study was done by using impendence tube method. Hemp/kenaf/kenaf/hemp hybrid laminates outperformed the other composites in terms of tensile strength, flexural strength and impact strength. In the mono reinforcements, hemp/epoxy composites demonstrated superior mechanical characteristics than the epoxy matrix and kenaf/epoxy composites. However, hybrid composites have superior mechanical behavior compared to pure composites. From the acoustic results revealed that the pure hemp and kenaf/hemp/hemp/kenaf hybrid composites exhibitted highest sound transmission loss level at lowest and highest frequency region. The bestmechanical characteristics of hybrid composites will be suggested for use in automobile door panels. Also, the optimal sound transmission coefficent values signifying their appropriateness for use in applications that encompass many frequency bands. Highlights: Hybridization of kenaf/hemp fibersImproved mechanical properties over the single fiber compositesBetter acoustic properties [ABSTRACT FROM AUTHOR]

This study explores the thermal and mechanical properties of a composite material formed by blending kenaf and basalt fibers with titanium oxide nanoparticles. To assess its performance under various conditions, we conducted thermogravimetric analysis (TGA) and hardness, sorptivity, and water absorption tests. During experimentation, composite samples were created using kenaf and basalt fibers as the reinforcing matrix and TiO2 nanoparticles as the modifier. Initial findings suggest that the addition of TiO2 nanoparticles enhances the mechanical properties and water resistance of the kenaf and basalt fiber composite. Samples reinforced with TiO2 demonstrated superior hardness and lower water absorption, i.e., KBT2 exhibited a hardness of 92 Hv and a water absorption rate of 6.4%. The value of 0.1% for KBT2 from the sorptivity investigation was promising, indicating its potential applicability in moisture-sensitive environments. In addition, TGA results show that KBT2 exhibited 0%, 2.1%, 4.7%, and 8.3% weight loss, showing improved thermal stability and high resilience to higher temperatures. In conclusion, the development of a novel material combining kenaf and basalt fibers reinforced with TiO2 nanoparticles presents a promising eco-friendly, durable, and lightweight option for engineering applications. Realizing the full potential of this composite material necessitates further characterization and optimization research. [ABSTRACT FROM AUTHOR]

Single-kenaf fiber-reinforced polymer composites are typically characterized by relatively low strength and stiffness properties that make them unsuitable for structural applications. However, they are lightweight, economical, and ecofriendly. This paper presents a study on the manufacturing and mechanical characterization of bidirectional kenaf (K) fiber-reinforced epoxy composites hybridized with carbon (C) fibers in various stacking sequences and the effects of hybridization on salient physical and mechanical properties. Single and hybrid fiber composites were fabricated utilizing the vacuum infusion molding technique. The density, tensile, flexural, and interlaminar shear properties in hybrid composites increased significantly when carbon fiber volume increased from 9% to 16%. Stacking sequences in a hybrid affected the mechanical properties of the composites. The highest tensile strength and modulus were shown by the seven-layer hybrid composite with an alternate K/C stacking sequence and C layers as skin layers, i.e., C/K/C/K/C/K/C, among all tested hybrid composites. Sandwich design in the hybrid (C2/K3/C2) had higher flexural strength (+300%), flexural modulus (+414%), interlaminar shear strength (+278%), lower water absorption (−46%), and thickness swelling (−30%) compared to single-fiber kenaf/epoxy composites. Density increased by 5% in hybrid composites. The highest fracture toughness (+134%) was achieved using the dual sandwich design structure hybrid (C/K2/C2/K2/C). The developed composite has applications in stairways, walkways, and bridges. [ABSTRACT FROM AUTHOR]

Kenaf fiber is gaining prominence because of its ability as a natural-based reinforced material in advanced composites. However, kenaf contains a hygroscopic natural waxy substance that covers the fiber layer, providing a low surface tension and preventing strong bonding with the polymer matrix. The goal of this study is to optimize the blending parameters of kenaf fiber-reinforced epoxy composites by alkali treatment concentration, length, and fiber-matrix loading using central composite design. The maximum tensile strength was obtained at 6.03 wt% of NaOH concentration, fiber loading of 26.02 wt%, and fiber length at 7.39 mm, which showed a strong correlation between experimental and predicted values. The analysis of variance function model indicated that fiber length, sodium hydroxide concentration, and fiber loading all play important roles in mechanical properties of composites. Based on the fracture surface observations, kenaf fiber composite strength was closely related to bonding at fiber-matrix interfaces. The most common failure modes in the samples were voids, matrix fracture, fiber breakage, weak bonding, and fiber pull-out. [ABSTRACT FROM AUTHOR]

Natural fibre-reinforced composites have been developed by researchers and industries as a solution to reduce the use of synthetic fibres. Kenaf fibre is one of the most abundant natural fibres in Indonesia. This study aimed to obtain the mechanical and thermal properties of kenaf fibre-reinforced epoxy laminated composites fabricated using a vacuum-assisted resin infusion method. The alkaline-treated fibres were arranged in the orientations 0°/0°/0°/0° and 0°/90°/0°/90°. Density measurements, mechanical tests, and thermogravimetric analysis were carried out on the epoxy and the composites. The results of the mechanical testing showed that the tensile, flexural, and compression strengths of the kenaf fibre-reinforced epoxy composites with a 0°/0°/0°/0° fibre orientation were higher than those of the composites with a 0°/90°/0°/90° fibre orientation, with values of (96.61 ± 10.18) MPa, (131.01 ± 6.60) MPa, and (71.96 ± 5.50) MPa, respectively. Scanning electron microscope observations showed that the composites had good fibre-matrix adhesion. The thermal stability of the epoxy was enhanced from 557 °C to 571 °C by incorporating kenaf fibre with 0°/0°/0°/0° orientation. With reference to the Indonesian National Standard 01-4449–2006, the two composites could be classified as T2 45 High Density Fibreboard. [ABSTRACT FROM AUTHOR]

Natural fiber reinforced polymeric composites perform poor in mechanical and thermal properties at elevated temperatures due to the cellulose and hemicellulose contents of natural fiber start degrading at elevated temperature. In this research work, flame retardancy and thermal stability of treated and untreated kenaf fiber reinforced epoxy composites have been experimentally investigated and reported. Two composite laminates, one with 6 % NaOH Alkali treated and another with untreated woven kenaf mats, were fabricated by hand lay-up technique followed by compression molding with 40 % fiber weight fractions. Flame retardancy test and various thermal characteristics studies such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), heat deflection temperature (HDT), and morphological analysis via scanning electron microscopy (SEM) tests were carried out. The results showed that alkali treated kenaf fiber composite achieved V0 fire retardancy grade. The major weight losses, 86 % and 75.5 % for untreated and treated composites respectively were recorded between 300 °C and 450 °C. 13.6 % increase in HDT was noted for treated composite with 0.25 mm deflection at 0.45 MPa pressure condition. Thus the composite laminate with 6 % NaOH alkali-treated kenaf fiber achieved the best thermal stability with less degradation which is more suitable for automobile and aerospace applications. [ABSTRACT FROM AUTHOR]

The use of fiber reinforced composites in dentistry is increasing due to its superior biomechanical properties. This study aimed to characterize the kenaf fiber reinforced nanohybrid dental composites derived from rice husk. Kenaf cellulose was treated with tetraethyl orthosilicate sol–gel which was characterized using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The experimental composites were fabricated using rice husk silica and kenaf cellulose at 1 wt% and 2 wt% and subjected for flexural and compressive strength tests. Fractured samples were examined using SEM. FTIR results suggested Si–O–C and Si–O–Si were formed on the cellulose surface at post-treatment. The flexural strength of the experimental composite was improved as the fiber load was increased. The composite with 2 wt% treated kenaf fibers showed higher compressive strength than the commercial composite groups. SEM analysis depicted fewer voids between matrix and kenaf fibers. In conclusion, 2 wt% fiber reinforced nanohybrid dental composites was successfully characterized and demonstrated a potential application in dental restorative material. [ABSTRACT FROM AUTHOR]

Due to renewable and environmental concerns, the creation of high-performance engineered goods created from natural resources is rising globally. Plant fibres are gaining popularity in polymer composites due to their environmental friendliness and lower cost than synthetic fibres. Because of its low density, Kenaf fibre offers superior specific characteristics than glass fibre as a reinforcement. Hence, development of composites for various applications plays a mojor role in industrial revolution. Kenaf plants, one of many distinct forms of natural resources, have been intensively exploited in recent years. As a result, this article provides an overview of recent advancements in the field of Kenaf fibre reinforced composites. Several essential challenges and future work proposals are highlighted, emphasizing the roles of material scientists and production engineers in ensuring the bright future of this novel "green" material through value addition to increase its use. [ABSTRACT FROM AUTHOR]

This research examines the impact of self-polymerized polydopamine (PDA) coating on the mechanical properties and microstructural behavior of polylactic acid (PLA)/kenaf fiber (KF) composites in fused deposition modeling (FDM). A biodegradable FDM model of natural fiber-reinforced composite (NFRC) filaments, coated with dopamine and reinforced with 5 to 20 wt.% bast kenaf fibers, was developed for 3D printing applications. Tensile, compression, and flexural test specimens were 3D printed, and the influence of kenaf fiber content on their mechanical properties was assessed. A comprehensive characterization of the blended pellets and printed composite materials was performed, encompassing chemical, physical, and microscopic analyses. The results demonstrate that the self-polymerized polydopamine coating acted as a coupling agent, enhancing the interfacial adhesion between kenaf fibers and the PLA matrix and leading to improved mechanical properties. An increase in density and porosity was observed in the FDM specimens of the PLA–PDA–KF composites, proportional to their kenaf fiber content. The enhanced bonding between kenaf fiber particles and the PLA matrix contributed to an increase of up to 13.4% for tensile and 15.3% for flexural in the Young's modulus of PLA–PDA–KF composites and an increase of up to 30% in compressive stress. The incorporation of polydopamine as a coupling agent in the FDM filament composite led to an improvement in tensile, compressive, and flexural stresses and strain at break, surpassing that of pure PLA, while the reinforcement provided by kenaf fibers was enhanced more by delayed crack growth, resulting in a higher strain at break. The self-polymerized polydopamine coatings exhibit remarkable mechanical properties, suggesting their potential as a sustainable material for diverse applications in FDM. [ABSTRACT FROM AUTHOR]

The integration of sustainable components in automotive parts is in growing demand. This study involves the entire process, from the extraction of kenaf cellulosic fibers to the fabrication of automotive parts by applying injection molding (sample only) and Resin Transfer Molding (RTM) techniques. Fibers were pretreated, followed by moisture content analysis before composite fabrication. The composite was fabricated by integrating the fibers with polypropylene, maleic anhydride polypropylene (MAPP), unsaturated polyester, and epoxy resin. Mechanical tests were done following ASTM D5083, ASTM D256, and ASTM D5229 standards. The RTM technique was applied for the fabrication of parts with reinforced kenaf long bast fibers. RTM indicated a higher tensile strength of 55 MPa at an optimal fiber content of 40%. Fiber content from 10% to 40% was found to be compatible with or better than the control sample in mechanical tests. Scanning Electron Microscope (SEM) images showed both fiber-epoxy-PE bonding along with normal irregularities in the matrix. The finite element simulations for the theoretical analysis of the mechanical performance characteristics showed higher stiffness and strength in the direction parallel to the fiber orientation. This study justifies the competitiveness of sustainable textile fibers as a reinforcement for plastics to use in composite materials for automotive industries. [ABSTRACT FROM AUTHOR]

In this study, kenaf natural fibers were coated with acetone‐thinned epoxy resin before compounding with high‐temperature polyethylene terephthalate (PET). Thus, composites of sodium hydroxide treated and epoxy‐resin coated kenaf fibers (KF) reinforced PET (CTKF‐PET) were manufactured using extrusion and compression molding techniques at an optimized 10 wt% constant fiber loading and processing temperatures of 240, 250, and 260°C, and were characterized for mechanical, thermal, and morphological performances. The obtained results showed an optimum processing temperature of 240°C with maximum mechanical and thermal properties with good interfaces between the coated fillers and the matrix, compared to those obtained at 250 and 260°C. Thermogravimetric analysis recorded maximum onset degradation and decomposition temperatures of 338.9 and 381°C with 9.5% and 13% improvements respectively after resin coating which positively impacted the constituent coated composites compared to the uncoated KF. Differential scanning calorimetry glass transition (Tg) and melting temperatures (Tm) for the CKF‐PET composites was maximum at 119.0 and 262.8°C with 2.18% and 2.8% improvements respectively compared to uncoated composites. The overall properties of all coated kenaf‐reinforced PET (CKF‐PET) and coated‐treated (CTKF‐PET) composites were higher with improved morphological properties irrespective of the processing temperature compared to the raw kenaf (KF‐PET) composites. Hence, natural fibers can be treated with resin coating to improve the thermal stabilities of natural fiber engineering plastic composites, and the interfacial adhesion between the coated‐KF and the engineering plastic matrix. The resultant composites are suitable for high‐temperature engineering applications such as the automotive and construction industries. [ABSTRACT FROM AUTHOR]

The application of natural fibers is increasing rapidly in the polymer-based composites. This study investigates manufacturing and characterization of polypropylene (PP) based composites reinforced with three different natural fibers: jute, kenaf, and pineapple leaf fiber (PALF). In each case, the fiber weight percentages were varied by 30 wt.%, 35 wt.%, and 40 wt.%. Mechanical properties such as tensile, flexural, and impact strengths were determined by following the relevant standards. Fourier transform infrared (FTIR) spectroscopy was employed to identify the chemical interactions between the fiber and the PP matrix material. Tensile strength and Izod impact strength of the composites significantly increased for all the composites with different fiber contents when compared to the pure PP matrix. The tensile moduli of the composites were compared to the values obtained from two theoretical models based on the modified "rule of mixtures" method. Results from the modelling agreed well with the experimental results. Tensile strength (ranging from 43 to 58 MPa), flexural strength (ranging from 53 to 67 MPa), and impact strength (ranging from 25 to 46 kJ/m2) of the composites significantly increased for all the composites with different fiber contents when compared to the pure PP matrix having tensile strength of 36 MPa, flexural strength of 53 Mpa, and impact strength of 22 kJ/m2. Furthermore, an improvement in flexural strength but not highly significant was found for majority of the composites. Overall, PALF-PP displayed better mechanical properties among the composites due to the high tensile strength of PALF. In most of the cases, T98 (degradation temperature at 98% weight loss) of the composite samples was higher (532–544 °C) than that of 100% PP (500 °C) matrix. Fractured surfaces of the composites were observed in a scanning electron microscope (SEM) and analyses were made in terms of fiber matrix interaction. This comparison will help the researcher to select any of the natural fiber for fiber-based reinforced composites according to the requirement of the final product. [ABSTRACT FROM AUTHOR]

The use of composite materials with natural fiber reinforcement (CMNFR) has experienced rapid development in the automotive industry to apply synthetic materials that are expensive and not environmentally friendly. Biocomposite is a composite consisting of a polymer matrix and natural fiber reinforcement. Natural fiber materials are used as a substitute for conventional non-renewable reinforcing materials. This study uses the vacuum-assisted resin infusion (VARI) process to fabricate composites using woven kenaf and jute from natural fiber. The Taguchi experimental design method with L273 as an orthogonal array matrix was used in this research to obtain the optimum CMNFR fabrication parameters. Response Surface Methodology is used to obtain the optimal response value based on microstructural analysis. The factors used were NaOH treatment (4, 6, 8 wt%), water absorption test (6, 12, 24 hours), and fiber type (KF, JF, KF-JF). The study's results found a combination of optimization of CMNFR manufacturing parameters using RSM, namely, A1B1C2 with a mean material strength of 0.241 J/mm2 (impact strength) and a combination of A1B3C1 parameters with a mean material strength of 94.8650 MPa (flexural strength). It was also found that the presence of contaminants and voids harmed the mechanical properties. [ABSTRACT FROM AUTHOR]

This study investigated the rheological and mechanical properties of cement composites with kenaf and jute fibers for use in shotcrete. The length and volume fractions of the fiber were varied; the rheological properties were analyzed in terms of air content, compression and flexural tests were conducted, and the degree of fiber dispersion was assessed using fluorescence microscopy. The rougher surfaces of the jute fibers led to a higher yield stress and viscosity of the composite compared to the kenaf fibers. The use of 10-mm-long jute fibers at 2.0% volume fraction led to optimal rheological properties while 30-mm-long jute fibers at 1.0% resulted in the worst properties. The yield stress and plastic viscosity exhibited positive and negative correlations with the fiber volume fraction, respectively. This was likely because of the bridging and fluid actions of the bubbles at higher fiber content. For a given fiber content, only the yield stress increases with an increase in fiber length. Although all the mechanical properties deteriorated (compressive strength decreased from 27.5 to 6 MPa, and flexural strength deteriorated from 6.2 to 1.8 MPa), the mixtures failed in a ductile manner. Using 10-mm-long kenaf fibers at 2.0% induced optimal fiber dispersion, whereas the minimum dispersion-coefficient value was found for 5-mm-long kenaf fibers at 0.5%. [ABSTRACT FROM AUTHOR]

Natural fiber reinforced hybrid polymer composites have attracted many researchers’ attention compared to synthetic fiber composites due to their better mechanical properties. Besides being inexpensive, natural fibers are eco-friendly. In the literature, kenaf fiber has shown an enormous future for its suitability in technical applications. The present studies explore the mechanical properties of kenaf and kapok fiber reinforced hybrid polyester composites. The composites are prepared by simple hand lay-up technique. The test specimens were prepared according to ASTM standards and the tensile, bending, and impact strength was evaluated experimentally. The result shows that composite with equal contribution of kenaf and kapok fiber reinforcement has tensile and impact strength of 25.25 ± 4.29 MPa and 46.65 ± 0.01 KJ/m² respectively. As the kapok fiber content increases the bending strength and bending modulus of composites decrease. The results show that the tensile and impact strength of hybrid composites has improved considerably compared to neat kapok composites. Scanning electron microscopy (SEM) was carried out to examine the fractured surfaces of tested specimens. [ABSTRACT FROM AUTHOR]

Natural fiber‐based materials are widely accepted in the composite sector as a substitute for synthetic fiber, particularly in structural and semi‐structural implementations in the automotive and aerospace industries, reflecting a recent trend and increased awareness of the importance of sustainable product design. Hand lay‐up was used to create natural fiber bilayer hybrid composites with epoxy matrix reinforcing oil palm empty fruit bunch (EFB) and kenaf fiber matting. The overall effect of this hybridization of the natural fiber and the thermal characterizations were studied experimentally. Both the hybrid combinations kenaf fiber and oil palm EFB were made by maintaining the fiber loading at 50% (weight) and weight ratios at 1:1, 1:4 and 4:1. The Tan delta, loss modulus (E″), storage modulus (E′), and Cole‐Cole plot were found to be useful in investigating dynamic mechanical properties. Dynamic mechanical analysis results like coefficient of performance and Cole‐Cole plot clearly show that hybrid pure kenaf composite has the significant complex modulus because interfacial bond between fiber and matrix is strong. As a result, it has been determined that kenaf fibers have the best mixing ratio for improving the dynamic mechanical properties of these hybrid type composites and can be used for aerospace, automotive, and civil engineering applications requiring high dimensional stability and excellent mechanical properties. The thermal gravimetric analysis data demonstrated that as compared to pure, the kenaf fibers and hybrid oil palm empty fruit bunch composites have the best thermal stability, with the highest beginning and ultimate breakdown temperatures of 200 and 450°C, respectively. [ABSTRACT FROM AUTHOR]

Limitation in practical applications of biopolymer–fiber composite is mainly at higher temperatures. Thus, this study highlights the effects of fiber orientation on the durability of polylactic acid (PLA) reinforced with unidirectional (UD) continuous kenaf fibers at elevated temperatures. PLA and long kenaf fiber were fabricated using the hot-pressing method and stacked at fiber orientations of 0°, 45°, or 90°, relative to the tensile force. Dynamic mechanical analysis of the composites shows excellent anti-shock and temperature-resistant properties of the composite. UD PLA–kenaf composites with a 0° fiber orientation showed an ultimate tensile of ∼190 MPa and a flexural strength of ∼235 MPa, and the strength of the composite was able to retain up to 120°C temperature. The debonding behavior of the fiber from the matrix (fiber pull-out) supported by microscopy proved that interfacial failure occurs from the local strains, which initiate cracking. Interfacial failure and stress transfer have caused a remarkable reduction in composite strength when fibers were oriented at 90°. Hence, this current improvement in the performance of the UD PLA–kenaf fiber composite may potentially replace conventional synthetic fibers, especially for structural automotive applications. [ABSTRACT FROM AUTHOR]

The research's aim is to investigate the energy absorption, free-fall drop analysis, and failure analysis of Palm (P)/kenaf (K) fiber-reinforced MWCNT-phenolic composites. 3P:7K reinforced MWCNT–phenolic composites were made using manual mixing and hot pressing at 150°C with a pressure of 10 tonnes. Energy absorption was investigated using a drop weight impact tester. Free-fall drop test was performed to analyze the performance of the aircraft tray table prototype. Non-destructive testing was carried out to investigate the damage mechanism. The results demonstrate that as the impact energy increased from 1.50 J to 3.0 J, the crack length increased. There is a difference of 3% to 15% in the crack sizing between dye penetration and Digital Detector Array (DDA), indicating that DDA is more accurate. In the free-fall drop test, small cracks were detected in the dye penetration method on the prototype. The DDA approach, however, did not reveal any defects. The agglomerations were observed through DDA and Computed tomography. In this study, the hybrid CR/kenaf reinforced MWCNT modified phenolic composites exhibit superior performance that can act as an efficient and eco-friendly material for aircraft tray table application by preserving natural resources. [ABSTRACT FROM AUTHOR]

In this study, the tensile and impact strength of nanocomposites reinforced with graphene nanosheets, basalt, and kenaf fibers were examined by response surface methodology (RSM). RSM with Box-Behnken design (BBD) was adopted as the study design. The polypropylene (PP) was melted and the reinforcements, including graphene nanosheets (at 0, 0.75, and 1.5 wt %), basalt fiber (at 0, 7.5 and 15 wt %), and kenaf fiber (at 0, 7.5, and 15 wt %) were incorporated to the matrix using mixing technique. The length of the fibers was similar for all the samples (5 mm). Tensile and impact tests were run for all samples to determine the weight of each reinforcing filler for gaining the maximum tensile and impact strength. The best tensile strength (34.434 MPa) was attained with a graphene nanosheet of 0.742 wt%, basalt fiber of 15 wt%, and kenaf fiber of 15 wt%. fabrication of composite having optimum levels of each variable yielded products with a 52% higher tensile strength than pristine PP. The best value obtained by impact tests was 129.9 J/m, which was achieved by graphene nanosheet of 0.984 wt%, basalt fiber of 15 wt%, and kenaf fiber of 15 wt%. The best weight combinations of these variables improved the impact strength by 80%. The SEM was also used to monitor the dispersal pattern of each of the reinforcing fillers in the matrix. FTIR characterization was used to analyze the change in the chemical structure of the composite, and results showed that the formation of new bonds between polymer chains and additives enhanced the mechanical strength of the composite. [ABSTRACT FROM AUTHOR]

Effect of fiber treatment on the strain We can conclude from figures presented previously that all composite tensile properties are improved when increasing the fiber weight ratio and also after the chemical treatment of the fibers used for. Fiber weight ratio of composites HT

Ramie fiber reinforced thermoplastic and thermoset polymer composites Ramie is the toughest bast fiber that yielded its fiber from the bark of the canes, which supplies exceptional raw material for blending with natural and synthetic fibers with higher luster, tenacity, brightness, and resistance to light, heat, alkali, and acid (Kiruthika [40]; Rehman et al. [74]). Hemp fiber reinforced thermoplastic and thermoset polymer composites Hemp fiber is another branch of bast fibers that are extremely used in the development of bio-based composites to prevail over the use of synthetic-based composite materials in the diversified application areas (Aisyah et al. [1]; Dixit et al. [18]). Kenaf fiber reinforced thermoplastic and thermoset polymer composites Kenaf fibers can widely be used in the fabrication of composite materials due to their higher mechanical properties. Digital images of different bast fibers: (a-a1) flax fibers, (b-b1) hemp fibers, (c-c1) jute fibers, (d-d1) ramie fibers, and (e-e1) kenaf fibers. Keywords: Natural bast fibers; thermoplastic and thermosetting polymers; classification; biodegradability; eco-friendly and sustainable composites; properties and applications EN Natural bast fibers thermoplastic and thermosetting polymers classification biodegradability eco-friendly and sustainable composites properties and applications 8006 8021 16 11/21/22 20221220 NES 221220 Introduction Composites are generally known as materials having multifunctional physical and chemical properties, which are manufactured by using two or more individual materials of different characteristics (Mastura et al. [49]; Sahu and Gupta [78]). [Extracted from the article]

Hybrid composite materials containing natural fibers are replacing conventional materials for automobile, aerospace and sports goods structural applications. Fiber extracted from plants and man-made fibers reinforced with polymer matrix find many applications because of improved characteristics, such as light weight and high strength. In this work, fabricated hybrid composites using chemically treated abaca, kenaf and carbon fiber reinforced with epoxy and teta hardener are studied. Hybrid composites have four stacking sequences and five layer composites made up of hand laid up then compression molding. Produced hybrid composites are subjected to various loads to determine the mechanical strength. Moisture absorption measured in the distilled water was used as the medium during water absorption test. Experimental results showed that the treated fiber hybrid composite provided higher mechanical strength and absorbed less moisture. The morphology of fractured surfaces was analyzed by electron microscopy. [ABSTRACT FROM AUTHOR]

The application of a sandwich structure made with composite facesheet and honeycomb core has increased rapidly due to high stiffness to weight ratio characteristics. There is a growing interest in using natural/synthetic hybrid composite to enhance the mechanical performance of natural fiber and reduce the environmental impact compared to synthetic materials. This study investigates the mechanical properties (tensile, edgewise compression, flexural) of the honeycomb sandwich structure with the hybrid composite facesheet, reinforced with different kenaf and glass fiber ratios. Non-hybrid kenaf and glass fiber composites were fabricated for comparison. The result showed that increasing the glass fiber ratio in a hybrid facesheet significantly improved the mechanical performance of the sandwich structure. Compared to the non-hybrid kenaf composite, the hybrid composite showed improved tensile and compression strength by up to 233% and 79%, respectively. The hybrid composite (glass/kenaf/glass) achieved 76% tensile modulus and 87% compression strength of glass fiber composite when the results were normalized. The specific flexural stiffness of the hybrid facesheet using glass fiber in the outer layer exhibited comparable performance by obtaining 89% flexural stiffness of non-hybrid glass composite sandwich structure. [ABSTRACT FROM AUTHOR]

In current centuries, emphasis has moved from previous resources and compounds to lightweight substances to generate softer, most effective components for particular needs. Using organic kenaf fibers with nanoreinforced epoxy polymers in a blended microbially nanocomposite can improve properties and be environmentally friendly. Adding graphene powder to the epoxy resin increases barrier and mechanical properties while maintaining rigidity without compromising toughness. To explore the impression of such parameters on the materials' properties of the construction, a mechanical test on nanocomposite features, such as size, filler content, and treatment effect, may be utilized. The elastic behavior, tension characteristics, and stress at vintage for three types of nanobased materials were calculated using the test results: graphite raw kenaf, nanosheets and sun-bleached kenaf fibers, salinized graphene oxide, and epoxy reinforced with salinized kenaf fibers. The impact of nanocomposite magnitude, filler concentration, and filler processing on mechanical properties is carefully investigated. According to the findings, the three-weight proportion of 75 nm-sized particles with salinized filler and kenaf fiber produces the maximum mechanical performance. Compared to other combinations, these combinations increase tensile strength by 16%. However, it appears to be beneficial when it comes to strength properties and deflection. Because of flaws and cavities at the micrometer level, the framework was less robust and distorted quickly after including a nanoparticle filler. [ABSTRACT FROM AUTHOR]

In this investigation, the dynamic mechanical properties of Indian almond – Kenaf fiber composite were investigated and the effect of stacking sequence was analyzed. Four types of composites viz. kenaf, Kenaf/Indian almond/Kenaf, Indian almond/Kenaf/Indian almond, and Indian almond were fabricated by hand layup technique. The experimental results revealed that the kenaf fiber composite showed the superior storage modulus and loss modulus values compared to all other composites due to the high stiffness of kenaf fiber and better bonding between the matrix and fiber. Among hybrid composites, Kenaf/Indian almond/Kenaf composite displayed a greater storage modulus and loss modulus than Indian almond/Kenaf/Indian almond composite due to the presence of two layers of high stiffness kenaf fiber. Further, the order of thermal stability of the composites was observed as: Kenaf > Kenaf/Indian almond/Kenaf > Indian almond/Kenaf/Indian almond > Indian almond. In addition, the Indian almond fiber composite and Indian almond/Kenaf/Indian almond composite exhibited good damping properties than other composites owing to the more mobility of polymer chain. Cole – cole plot showed that the structure of all the fabricated composites was heterogeneous in nature and kenaf fiber composite displayed the higher heterogeneity among all other materials. Moreover, the modeling of storage modulus and damping factor was performed and compared with the experimental results. The results showed good agreement with the theoretical and experimental values. [ABSTRACT FROM AUTHOR]

This study sustainably developed natural fiber composites from extracted nano-cellulose (ENC) from waste paper egg trays and incorporated them into vinyl ester/kenaf fiber (ENCVK) composites using a vacuum-assisted resin transfer molding (VARTM) process. Overhead stirring, three-roll milling, and ultrasonication were used to uniformly mix the ENC into the resin. The surface morphology exhibited a homogeneous distribution of ENC in the composites, and change in the % of transmittance of spectral peaks refers to the chemical interaction of ENC with the VK composites. ENC significantly improved tensile (32 MPa), flexural (77 MPa) and impact (0.0197 J/mm2) properties of the VK composites (18 MPa, 61 MPa and 0.009 J/mm2) by approximately 73%, 25% and 110%, respectively. Further, ENC inclusion enhanced the storage modulus of VK composites owing to the addition of rigid ENC particles, which enhances the bearing capacity of the composite and is reflected in its high performance. The loss modulus indicates that the interfacial interaction of ENCVK is more vital than VK. The tan Δ value indicates that the filler has strong adhesion, and the polymer cohesion damping is reduced, thus reflecting its high performance. [ABSTRACT FROM AUTHOR]

Alkali treatment of natural fibers will improve the mechanical, chemical, and thermal characteristics of natural fiber reinforced epoxy composites. The influence of alkali treatment on the improvement of mechanical strength of natural fiber reinforced epoxy composites depends on the selection of process parameters of the treatment. In this work, the optimization of four key process parameters for alkali treatment of kenaf fiber has been studied using orthogonal array-oriented fractional factorial experimental design. The concentration of sodium hydroxide solution, process temperature, time, and fiber to solution weight ratio were the four chosen parameters and the tensile strength of the composite sample fabricated with treated kenaf fiber and epoxy resin was taken as output response. The hand layup method was used to fabricate the composite materials, and specimens were prepared for the tensile test. All samples were fabricated by ensuring the fiber weight ratio of 40%. Five samples were prepared at each experiment category, and mean values were taken for analysis. The results revealed that 6% NaOH solution, 30°C process temperature, 8 hours process time, and 1:15 fiber to solution weight ratio are identified as optimum process parameters for a tensile strength of 58.16 MPa. [ABSTRACT FROM AUTHOR]

The effect of jute, kenaf, and banana fiber reinforced epoxy hybrid composites with different stacking sequences were fabricated by compression molding techniques. The pure epoxy, pure jute, pure kenaf, pure banana composites are also fabricated for comparison purposes. Tensile, flexural, inter‐laminar shear strengths, and hardness properties of the fabricated composites were investigated. Physical parameters like density, water absorption, and thickness swelling were also examined. From mechanical properties, the results are evident that when compared to hybrid composites pure banana composites have the highest tensile, flexural, interlaminar shear strength and shore D hardness value of 41, 67, 18, and 86 MPa respectively. Also, pure banana composites have better water absorption and thickness swelling percentage of 4% and 1.6%. However, KBJJBK hybrid composites exhibit a maximum tensile strength of 34 MPa, flexural strength of 54 MPa. Further BJKKJB hybrid composites possess the highest hardness value of 87, intralaminar shear strength of 17 MPa and lowest water absorption of 8% and thickness swelling percentage of 2%. Certain pure and hybrid configuration have enhanced mechanical strength, stiffness, and lower water absorption and thickness swelling properties, indicating that they are suitable for automotive structural applications. [ABSTRACT FROM AUTHOR]

The current research has produced engineering plastics composite for automotive applications using waste recycled plastic recycled polyethylene terephthalate (RPET) bottles as the matrix and compounded with chemically modified natural kenaf fibers in comparison with virgin polyethylene terephthalate (PET) composites under the same processing conditions. Kenaf fibers were surface modified by alkali and epoxy coating treatment methods. The waste RPET bottles which were mechanically recycled were pulverized using a 5 mm mesh size aperture into flakes and melt‐mixed with 10 wt% of short kenaf fibers in a twin‐screw extruder and compression‐molded at 240°С optimized temperature. Mechanical and thermal analyses were performed on both RPET, virgin PET (VPET), and their constituent kenaf composites. Scanning electron microscopy (SEM) was carried out to assess the composite's morphological characteristics. The results show that both treated (TKF/RPET and TKF/VPET) composites gave higher mechanical properties compared to untreated (KF/RPET and KF/VPET) composites. RPET and its constituent composites show higher impact properties than VPET composites. However, the tensile and flexural strength of VPET composites was higher than that of recycled RPET composites. RPET and VPET showed melting peak temperatures of 252.9°C and 245.8°C respectively. Both treated TKF/RPET and TKF/VPET composites were more thermally stable and decomposed at higher temperatures compared to the untreated composites. The SEM results for both treated composites showed a strong fiber/matrix adhesion with no clear evidence of fiber degradation as compared to untreated composites. It can be concluded that RPET possessed similar thermal properties compared to its virgin counterpart and can serve as a substitute for virgin PET in the composite formulation. [ABSTRACT FROM AUTHOR]

Due to its enhanced strength, stiffness, and tensile qualities, fibre reinforced composites are being employed more and more in the aerospace, automotive, plastic and mineral processing industries. Kenaf, jute, Kemp, and other types of reinforcing fibres are frequently utilized and come in strips. The design and analysis of the mechanical characteristics of the Kenaf fibre reinforced composite is the primary goal of this project. Different combinations of fibre and resin are examined for their various mechanical qualities, such as impact resistance, flexural strength, and tensile strength. By altering the fibre orientation and boosting impact strength, the composite is created. By altering the fibre orientation and boosting impact strength, the composite is created. The composite is personally examined using a variety of testing tools, and it is also examined using design software like Ansys. This research aims to increase the composite’s impact strength by adjusting the fibre length. The hydrogen peroxide solution is also coated on the composite before the tests are run. Comparisons are made between the experimental findings for coated and uncoated composites. [ABSTRACT FROM AUTHOR]

The effect of different concentrations of epoxy surface coating treatment on the thermal and mechanical properties of kenaf fiber reinforced recycled poly (ethylene terephthalate) (RPET) composites was studied. Silane-treated kenaf fibers (SKF) were epoxy-coated with optimized coating concentrations (in the ratios of 1:4, 1:5, and 1:6 epoxy to acetone solutions) to improve the thermal degradation/decomposition resistance and interfacial bonding with RPET matrix. The different epoxy coated-silane treated kenaf fibers 1:4 ESKF, 1:5 ESKF, and 1:6 ESKF were compounded with RPET at an optimized temperature of 240°C, and their constituents' composites KF/RPET, 1:4 ESKF/RPET, 1:5 ESKF/RPET, and 1:6 ESKF/RPET were subjected to thermal, mechanical and microstructural investigation. The obtained results showed some remarkable effects of epoxy concentrations on the chemical and surface structures of the treated fibers. Thermal properties of both ESKF and ESKF/RPET composites were more stable and improved with different concentrations of epoxy treatment compared to the untreated counterparts. 1:4 ESKF and 1:5 ESKF were the most thermally stable with onset degradation and DTG decomposition temperatures of 331.6°C and 381.7°C, and 324.0°C and 388.7°C respectively. Mechanical properties of the epoxy-coated composites were higher and further improved with epoxy concentrations and fiber loadings compared to uncoated composites. Hence, the epoxy concentration of 1:4 gave the maximum tensile and impact properties, and at 10 wt. % fiber loading within the lower loading regions, followed by 1:5 with outstanding flexural properties. The coated-treated composites showed strong fiber/matrix bonding with no evidence of fiber decomposition compared to the untreated composites with poor fiber/matrix interaction. The current research findings are original and valid for improving the thermal degradation resistance and stability of natural fibers, and the mechanical properties of natural fiber reinforced engineering thermoplastic composites. The epoxy coated – silane-treated textile kenaf fibers reinforced with recycled PET composites have the potentials to be utilized in high-temperature industrial and engineering applications. Graphical Abstract [ABSTRACT FROM AUTHOR]

Natural-based composite's progress as carriers has revealed many benefits in biomedicine, notably in the construction field, synthetic biology, and genetic engineering. Compared to analogous composites without nanoparticles, incorporating nanoparticles into polymeric materials improved architectural performance, physiological connections, and ecological features. The major goal of the current investigation is to determine the impact of nano-/micro-TiO2 on the mechanical characteristics of kenaf/glass/epoxy hybrids. The samples have been created using a hand layup method and a variety of filler loading and stacking sequences. The addition of nano-/microfiller significantly improved the mechanical performance of the epoxy/hybrid composite material. It was discovered that nanofiller-added composite materials fared better when composites were compared to and without microfilter-added composites. SEM was used to investigate the microstructure of the interfaces to ensure a good understanding of interfacial adherence between the reinforcement and their matrix. Compared to pure epoxy resin, the 15 wt% of microfiller additions of glass-kenaf-kenaf-glass type composites exhibit a 39.48% improvement in tensile and a 42.88% improvement in flexural. Similarly, 5 wt% nanofiller addition reveals a 44.214% improvement in tensile and a 50.50% improvement in flexural. [ABSTRACT FROM AUTHOR]

Several industry sectors have sought to develop materials that combine lightness, strength and cost-effectiveness. Natural lignocellulosic natural fibers have demonstrated to be efficient in replacing synthetic fibers, owing to several advantages such as costs 50% lower than that of synthetic fibers and promising mechanical specific properties. Polymeric matrix composites that use kenaf fibers as reinforcement have shown strength increases of over 600%. This work aims to evaluate the performance of epoxy matrix composites reinforced with kenaf fibers, by means of dynamic-mechanical analysis (DMA) and ballistic test. Through DMA, it was possible to obtain the curves of storage modulus (E′), loss modulus (E″) and damping factor, Tan δ , of the composites. The variation of E′ displayed an increase from 1540 MPa for the plain epoxy to 6550 MPa for the 30 vol.% kenaf fiber composites, which evidences the increase in viscoelastic stiffness of the composite. The increase in kenaf fiber content induced greater internal friction, resulting in superior E″. The Tan δ was considerably reduced with increasing reinforcement fraction, indicating better interfacial adhesion between the fiber and the matrix. Ballistic tests against 0.22 caliber ammunition revealed similar performance in terms of both residual and limit velocities for plain epoxy and 30 vol.% kenaf fiber composites. These results confirm the use of kenaf fiber as a promising reinforcement of polymer composites for automotive parts and encourage its possible application as a ballistic armor component. [ABSTRACT FROM AUTHOR]

An experimental investigation was conducted to identify the optimum fiber content and the effect of fiber alkaline treatment on kenaf fiber reinforced epoxy composites and reported in this article. The entire research work was carried out in two phases. In first phase, kenaf fiber reinforced epoxy composites with fiber weight fractions 20%, 30%, 40%, and 50% (on the total weight of composites) of raw untreated fibers were fabricated using hand layup followed by compression molding to identify the optimum fiber content. The prepared specimens were tested for tensile, flexural and impact properties as per corresponding ASTM standards. In the second phase the optimal fiber weight fraction was chosen to identify the effect of chemical treatment of kenaf fiber mats with NaOH and KOH solutions on mechanical properties. Based on the test results the optimum fiber content was identified as 40% with 45.98 MPa, 40.50 MPa, and 13.26 kJ/m2 as tensile, flexural and impact strength respectively; and 6% NaOH treatment recorded highest mechanical properties of composite such as 58.34 MPa in tensile, 55.34 MPa in flexural and 16.69 kJ/m2 in impact strengths respectively. Also 6% NaOH treatment shown 26.88%, 37.28%, and 25.87% improvement on tensile, flexural, and impact strengths respectively. [ABSTRACT FROM AUTHOR]

This paper is focused on developing composites using kenaf fibers, epoxy polymer, and incorporation of graphene fillers. The kenaf fibers are treated with 5% NaOH to remove the hydrophilic nature and reinforced it with the hydrophobic matrix. The composites are fabricated using the compression moulding technique by keeping 60 wt.% epoxy as constant, and the graphene and kenaf fiber weights are changed accordingly. The samples for tensile, flexural, impact, hardness, and water absorption tests are prepared as per the ASTM D3039, D790, D256, D2240, and D572 standards, respectively. The effect of graphene fillers in the 5% NaOH-treated kenaf fibers reinforced with the epoxy matrix is tested. Among the various samples, sample 4 which has 6% graphene addition in the epoxy matrix reinforced with 5% treated kenaf fiber displayed the highest tensile strength of 63 MPa, flexural strength of 97 MPa, impact strength of 9.56 kJ/m2, hardness value of 97, and lower water absorption of 5.13%. This is due to the proper dispersion of graphene fillers in the matrix which caused better interfacial adhesion between the fiber and matrix. The water absorption test showed the lowest value in sample S5 as the graphene fillers obstruct water penetration in the fibers. SEM analysis is done on the prepared samples to study the surface flaws and structural changes. [ABSTRACT FROM AUTHOR]