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This study evaluates energy-economic (2-E) efficiency by reducing the glass cover temperatures and enhancing the condensation rates in solar desalination systems. This improvement is accomplished by incorporating natural kenaf fibers. The research introduces an innovative modification to a conventional solar desalination system (CSDS) by implementing a water-dripping mechanism using kenaf fibers positioned atop the glass cover. Experimental investigations were conducted on both the unmodified CSDS and the solar desalination system with kenaf fibers (SDSK) under analogous meteorological conditions to scrutinize the impact of natural fibers on freshwater production within an environmentally sustainable solar desalination paradigm. The integration of water dripping and fibers significantly led to a substantial reduction in glass temperatures, manifesting as a 30% decrease compared to the conventional CSDS. Furthermore, the distillate productivity of SDSK exhibited a remarkable enhancement of 48% relative to CSDS. Beyond its thermal performance, the cost per liter of potable water obtained from SDSK was determined to be ₹1.35, accompanied by a swift payback period of merely 3.9 months. In contrast, the corresponding figures for CSDS were ₹2.32 and 5.7 months, respectively. These findings underscore the advantages of incorporating kenaf fibers and water-dripping technology in solar desalination. This results in enhanced performance and cost-effective and expedited access to clean drinking water. [ABSTRACT FROM AUTHOR]

This study aims to investigate the tensile strength of the polypropylene-based bio-composites reinforced with natural kenaf fibers, basalt fiber, and nanographenes. The response surface methodology was used to investigate the behavior of the bio-composites based on the weight percentage of basalt and kenaf fibers and nanographenes. The behavior of the samples was analyzed using the tensile test, and the results were interpreted using field emission scanning electron microscope images. The fracture surface of the samples indicated the fibers' breakage and their separation as well as the pullout of the fibers from the substrate as the main mechanisms in improving the behavior of the bio-composite under study. Then, the multi-objective optimization was performed by increasing the tensile strength and elastic modulus and reducing the weight of the samples, and a Pareto diagram was drawn according to the design objectives. The results showed that the bio-composite sample in the optimal status with the maximum tensile strength of 30.9481 MPa and the lowest weight includes 15% kenaf fibers and 0.862% graphene nanoparticles. Moreover, the optimal sample of the bio-composite with the highest elastic modulus of 3.5126 GPa and the minimum weight of 1.626 g consists of 15% of kenaf fiber and 1.5% of graphene nanoparticles. Twenty-seven percent reduction in composite weight by optimizing the amount of reinforcements causes the weight of the final structure to be significantly reduced in the use of these composite plates in high volumes. [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]

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]

• Fiber yield and quality phenotypic data suggested the agronomic traits are quantitative traits controlled by multiple genes. • A high-resolution genetic map with 1997 polymorphic SNP markers was constructed. • Six QTLs related to fiber yield and fiber quality were identified. • The SNP markers un_59,437,998 and un_56,233,383 were closely linked to fiber yield agronomic trait and the two SNP markers can be candidate molecular markers for determining the fiber yield during breeding. Kenaf fiber extracted from kenaf stem bast is an important natural fiber. The genetic basis of fiber yield and quality is poorly understood. In the present study, Fiber yield and quality phenotypic data showed continuous positive distribution or positively skewed distribution. Fiber yield traits and its related traits including plant height, fresh bast weight, dry bast weight showed a positive correlation. However, there was a negative correlation between fiber weight and fiber count. The results showed that the fiber yield and quality agronomic traits are quantitative traits controlled by multiple genes. Quantitative trait locus (QTL) mapping is a useful method for revealing the mechanism of complex genetic traits and identifying new genomic information to accelerate crop improvement. In this study, a total of 1,997 polymorphic SNP markers were successfully mapped onto 18 different linkage groups. Meanwhile six QTLs were identified based on the genetic map using the multiple QTL mapping (MQM) method, which were assigned to three linkage groups, LG16, LG8, and LG3. QTL-Plant hight, QTL-Fresh bast weight, QTL-Dry bast weight and QTL-fiber weight were related to fiber yield, while QTL-fiber strength and QTL-fiber count were related to fiber quality. This is the first study of its kind to map QTL of fiber yield and fiber quality, which will facilitate further understanding of the molecular genetic basis of these traits. However, there are limitations regarding the utilization of this map because several large gaps remain in some linkage groups. Therefore, additional markers need to be developed to further narrow these regions. [ABSTRACT FROM AUTHOR]

This research is a comparative study of untreated and treated date palm fiber (DPF) and kenaf (KF)-reinforced epoxy hybrid composite and explores the properties of DPF. The prepared hybrid composites were characterized in terms of tensile properties, impact properties, physical behavior, water absorption, and thickness swelling. The composites were prepared by hand layup technique. Treated 30% date palm and 70% kenaf (T-3DP7K) showed the highest tensile strength (26.45 MPa) and modulus (4.54 GPa) among untreated and treated hybrid composites. The scanning electron microscope revealed the behavior of fiber and polymers and also the cause of tensile test failure. The impact strength of T-1DP1K revealed highest impact resistant (5493 J/m) among untreated and treated hybrid composites. Remarkably, alkali-treated hybrid composites reduced the water absorption and thickness swelling compared to the untreated composites. In untreated composites, higher DPF content composites showed higher moisture content and dimensional instability. Overall, we concluded that among all hybrid composites, T-3DP7K showed better tensile properties, lowest water absorption, and lowest thickness swelling, and T-7DP3K showed better impact properties. [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]

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]

Natural fibers are very flexible materials; their properties vary with physical structure and chemical composition. Chemical treatment of fiber can chemically modify, clean the fiber surface, increase the surface roughness and stop the moisture absorption process. In the present study, kenaf bast fibers were treated with sodium hydroxide (NaOH), sodium carbonate (Na2CO3), ortho phosphoric acid (H3PO4), acetic acid (CH3COOH) and zinc chloride (ZnCl2) each with different concentrations. The morphological properties were investigated using scanning electron microscopy (SEM) which shows many impurities on untreated kenaf fiber surface. NaOH and ZnCl2 treated kenaf fiber surface is more rough than other chemical treatments. X-ray diffraction (XRD) was carried out to evaluate crystallinity index. NaOH treated kenaf fiber shows highest crystallinity index of 76.87%. Fourier transform infrared (FTIR) spectroscopy was performed to characterize chemical functional groups. In untreated kenaf fiber broad band at 3469 cm−1 confirms the presence of OH group. After chemical treatments this band disappears which confirms the removal of the OH groups. Thermo gravimetric analysis (TGA) carried out shows low fixed carbon content (64%) and maximum ash content (22%) for NaOH treated kenaf fiber. [ABSTRACT FROM AUTHOR]

Among most of the natural fiber reinforced polymer composites, the specific wear rate of epoxy-kenaf fiber composite is the second least after sisal-polyester composite (El-Tayeb [10]). Conclusions The present investigation exposed the following conclusions: The preparation of hybrid polymer composites using an industrial/construction waste (marble dust) and natural fiber (kenaf) is possible using the polymer solution casting technique. Keywords: Polymer composites; waste marble dust; kenaf fiber; characterization; dry-sliding wear; ANN EN Polymer composites waste marble dust kenaf fiber characterization dry-sliding wear ANN 9235 9247 13 11/21/22 20221220 NES 221220 Introduction Polymers and their composites are growing as the emerging functional materials due to their excellent engineering properties like high corrosion resistance (Santos et al. [28]), lightweight (Phadtare et al. [22]), bio-degradability (Thakur, Thakur, and Gupta [33]), high strength (Ku et al. [16]), and improved wear resistance (Friedrich, Reinicke, and Zhang [12]). [Extracted from the article]

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

–The sustainable utilisation of Kenaf fibres (KF) as environmentally friendly reinforcement in mortar, concrete and polymer composites promotes the concept of a circular economy and sustainable construction. However, the hydrophilic nature of such biofibres adversely affects their structural applications as reinforcement in concrete, mortar and polymer. Therefore, the study examined the effect of alkali treatment (mercerization) on the surface sorption characteristics of KF. The effect of water sorption characteristics on the mechanical properties of surface-modified and untreated KF was also investigated in the study. Scanning electron microscopy was performed to examine the morphology and microstructure of the fibre surface along with the tensile fracture of the swollen/un-swollen fibres. The water absorption studies revealed that mercerization reduced the overall water uptake of KF by 16%, which enhanced the adhesion of the fibre surface. The findings provide the knowledge required by scientists and engineers for determining the water requirements for the design of bio-fibrous concrete composites. [ABSTRACT FROM AUTHOR]

Cement concrete is used in small structure to big multi-storied buildings. It is noteworthy to concentrate on concrete elements and mix ratio to achieve desirable strength with feasible cost of raw material. In this investigation, fibers reinforced concrete specimens (M50 grade) were prepared. The strength and durability were tested and compared with the properties of plain concrete (PC). The fibers such as coir, kenaf, and Polypropylene (PP) were used as reinforcement and the compressive, split tensile, flexural, and durability analysis were performed. The compressive test resulted that the natural fiber-based PC/Coir & PC/PP-Coir specimens displayed the maximum compressive strength of 64.5 and 66 MPa owing to the small density and slighter water up taking properties of coir and PP fiber. The split tensile test showed that the PC/kenaf specimen exhibited the higher split tensile strength of 7.3 MPa due to the presence of kenaf fiber with high young's modulus. Flexural test reported that the PC/PP-Coir/Kenaf specimen exhibited the higher flexural strength of 7.6 MPa because of reinforcing effect offered by coir, kenaf, and PP fibers. Durability study showed that the PC/PP and PC/PP-coir specimens displayed the minimum weight loss of 1.05 and 2.1% and the minimum loss in compressive strength of 3.4 and 4.6%, respectively, in alkaline medium. It was concluded from this study that the coir fiber could be a suitable candidate to improve the strength and durability of concrete. [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]

Construction industries demand a material with high strength to endure severe environmental conditions like high temperature and humid and hence, it is noteworthy to assess the thermal and water transport properties of the material. In this investigation, the natural fibers based composites were fabricated using Indian almond and kenaf fibers by hand layup method. Entirely, two natural fiber composites viz. epoxy/Indian almond & epoxy/kenaf and two hybrid composites viz. kenaf/India almond/kenaf (K/I/K) & Indian almond/kenaf/Indian almond (I/K/I) were prepared. Thermogravimetric analysis (TGA) was carried out to analyze the thermal properties and water absorption study was carried out to analyze the transport properties. TGA study showed that the epoxy/kenaf composite exhibited a maximum onset temperature of 340.49°C owing to good bonding strength and the K/I/K composite displayed a maximum decomposition temperature of 380.21 ° with a minimum mass loss of 1.29 mg/min. Further, the epoxy/Indian almond composite showed a better flame retardancy property due to more char formation. Water absorption study resulted that the epoxy/Indian almond composite absorbed more water (35% at 50°C) compared to other composites due to spongy like structure and the presence of more voids on the surface of the fiber. Further, the epoxy/kenaf composite displayed more resistance to water penetration with maximum activation energy of diffusion of 2.63 kJ/mole. Transport properties such as diffusion coefficient, sorption coefficient and permeability coefficient were varied in line with temperature. The epoxy/kenaf composite showed least diffusion coefficient of 2.48 × 10−5 cm2/s, sorption coefficient of 1.05, and permeability coefficient of 2.61 × 10−5 cm2/s at 30°C among all other composites due to good bonding strength. [ABSTRACT FROM AUTHOR]

Surface treatment of natural fibers with the help of chemicals has been proved to be an effective method for improving the properties of its associated composites. The present research investigates the effect of nonacidic and cost-effective chemical treatment using sodium acetate on the properties of kenaf mats reinforced Polylactic acid (PLA) composites. In particular, geometrically different kenaf fiber mats (unidirectional, bidirectional, and randomly oriented) were chemically treated with varying concentrations (10%, 15%, and 20% w/v) of sodium acetate, for three different time periods (24, 48, and 72 h) at room temperature. Effect of chemical treatment on the surface of kenaf fibers was examined by scanning electron microscopy. Mechanical characterization of the developed composites was done on the basis of tensile, flexural, and impact tests to investigate the effect of treatment on interfacial adhesion. The composites in which fibers were treated with a 20% concentration of sodium acetate at 48 hr of treatment time exhibited the highest tensile, flexural, and viscoelastic properties. Apart from impact strength, the effect of chemical treatment on the properties of green composites was found to be significant. Eco-friendly treatment of natural fibers using sodium acetate may offer huge potential for commercialization of green composites in furthermore applications. [ABSTRACT FROM AUTHOR]

Natural fibers have emerged as a potential alternate to synthetic fibers, because of their excellent performance, biodegradability, renewability and sustainability. This research has focused on investigating the thermal, visco-elastic and fire-retardant properties of different hybrid Cytostachys Renda (CR)/kenaf fiber (K) (50/0; 35/ 15, 25/25, 15/ 35, 0/50)-reinforced MWCNT (multi-walled carbon nanotubes)-modified phenolic composites. The mass% of MWCNT-modified phenolic resin was maintained 50 mass% including 0.5 mass% of MWCNT. In order to achieve homogeneous dispersion ball milling process was employed to incorporate the MWCNT into phenolic resin (powder). Thermal results from thermogravimetric analysis and differential scanning calorimetric analysis revealed that the hybrid composites (35/15; 35 mass% CR and 15 mass% K) showed higher thermal stability among the composite samples. Visco-elastic results revealed that kenaf fiber-based MWCNT-modified composites (0/50; 0 mass% CR and 50 mass% K) exhibited higher storage and loss modulus due to high modulus kenaf fiber. Fire-retardant analysis (UL-94) showed that all the composite samples met H-B self-extinguishing rating and exhibited slow burning rate according to limiting oxygen index (LOI) test. However, (15/35; 15 mass% CR and 35 mass% K) hybrid composites showed the highest time to ignition, highest fire performance index, lowest total heat release rate, average mass loss rate, average fire growth rate index and maximum average rate of heat emission. Moreover, the smoke density of all hybrid composites was found to be less than 200 which meets the federal aviation regulations (FAR) 25.853d standard. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was carried out to select an optimal composite sample considering the thermal, visco-elastic and fire-retardant behaviors. Through TOPSIS analysis, the hybrid (15/35; 15 mass% CR and 35 mass% K) composite sample has been selected as an optimal composite which can be used for high-temperature aircraft and automotive applications. [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]

There has been a huge demand in industries for the design and development of bio‐degradable and low‐cost wear resistant composite materials since long. In response to this, the present work includes an exhaustive analysis for the solid particle erosion characteristics of a new class of hybrid polyester composites reinforced with a natural fiber (kenaf) and filled with a construction waste (marble dust) in different proportions. The test trials on the composite samples are conducted using a DUCOM high temperature erosion test rig as per ASTM G76. The experimentation and analysis are conducted as per the L30 model of response surface method (RSM). The results revealed that the incorporation of marble dust enhanced the resistance to erosion wear of the fiber‐polyester composites and among the control factors, the contributions of striking velocity and angle of impingement towards the erosion rate are significant. A predictive model working on the concept of neural networks (ANN) is used for the prediction of erosion rates at different levels and combinations of the significant control factors. The mechanisms of erosion loss are identified from the morphologies of the worn surfaces taken using a scanning electron microscope. [ABSTRACT FROM AUTHOR]

This work explores the feasibility of fused deposition modelling (FDM) to produce kenaf fiber/thermoplastic polyurethane (TPU) composites. Internal mixer was used for mixing different weight percentage (0, 5 and 10 wt %) of kenaf fiber with TPU before being extruded to produce filament for FDM feed stock. Addition of kenaf fiber was found to give benefits on dimensional stability of the printed samples which is importance for its implementation in FDM. TPU filled with 10wt% of kenaf fibre showed improvements in hardness and Young modulus of 15% and 49%. However, the tensile strength, elongation at break and density of the printed samples decreased with increasing kenaf fiber loading. This could be explained due to increase of voids and porosity within the material and poor wettability between TPU matrix and kenaf fiber which is evidenced by SEM observation. [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]

Bio-composites filled with natural and bio-fibers can lead to novel green products. However, in terms of processing, there still exist serious challenges in the development of bi-based parts with respect to the materials selection and limitations associated with the fabrication route. Further issues rise when a uniform and homogenous blending of bio-based constituents is required. This study examines the feasibility of two roller mixer method (calendering) in the sheet fabrication of natural kenaf fiber/carbon black (CB) reinforced polylactic acid (PLA) on the basis of melt mixing. To do this, composites of 20 wt% kenaf, based on an optimized filler content, were reinforced with 0–10 wt% of CB to enhance the processability and to evaluate the synergistic effect of CB on kenaf/PLA parts. The results showed a 75% increase in the modulus of the pure PLA filled with 20 wt% kenaf whilst representing the greatest tensile strength amongst kenaf/PLA specimens. Specimens reinforced with 5 and 10 wt% of CB exhibited enhancement in the elongation at break with respect to the reference neat kenaf/PLA composites, which was attributed to the lowered crystallites size and softer interfacial interphase. However, with the addition of only 5 wt% of CB, the tensile modulus and the crystallization improved by ~ 50% compared to that represented by neat kenaf/PLA parts. The microstructural images confirmed the aligned kenaf phase, dispersion state and interfacial bonding of the CB/kenaf/PLA specimens in correlation with the thermal and mechanical response of the specimens. [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]

Owing to the increasing demand for high performance and lightweight materials, fiber metal laminates (FMLs) have become the alternative materials to replace metallic alloys. When the environmental friendliness of the materials is taken into consideration, plant fibers have shown an excellent potential to be employed as the reinforcements in FMLs. This work describes the mechanical behavior of kenaf and pineapple leaf fibers (PALF) reinforced metal laminates with various fiber contents, ranging from 10 wt% to 50 wt%. Fiber metal laminates were formed through the coalescence of metallic skin layers with the composite as the core. The mechanical tests were then conducted to study the tensile, flexural and Charpy impact properties of the structures. From the findings, it was concluded that both the kenaf and PALF based FMLs showed the optimum mechanical properties when the fiber content was fixed at 30 wt%. In addition, PALF based FMLs had shown higher mechanical properties over kenaf based FMLs. At a fiber content of 30 wt%, the tensile and flexural strength of PALF based FMLs were respectively 6.18% and 3.44% higher than kenaf based FMLs. In terms of impact properties, the impact strength of PALF based FMLs was 5.06% and 40.73% higher than kenaf based FMLs in the flatwise and edgewise orientations. [ABSTRACT FROM AUTHOR]

An eco-friendly and effective degumming method needed to be developed for producing kenaf bast fibers. This study devised a novel deep eutectic solvent (DES) method coupled with microwave and alkaline-ultrasonic treatment. The novel method could effectively remove the gummy matters, providing a smooth and clean fiber surface. The properties of the fibers were assessed including chemical compositions, surface structure, crystallinity index (66.68%) and thermal properties. The residual gum content (9.419%), fiber fineness (4.125tex), breaking tenacity (13.650 cn/tex) of the refined dry fibers produced by the novel treatment were comparable with the fibers produced by the traditional two-step alkali boiling method. Besides, the novel method could reduce the usage of chemical, water and time by 48.9%, by 66.7% and 66.8%, respectively. These results revealed that the novel combined DES pretreatment is a practical and feasible pretreatment method for kenaf bast degumming, demonstrating its facile, green energy-saving and fast properties in the degumming process. [ABSTRACT FROM AUTHOR]

In recent years, natural fibers have been used more frequently for their lower weight to strength ratio, low cost, and environmental-friendly attributes. In this work, sisal/kenaf fiber reinforced with epoxy matrix hybrid composite (HC) was manufactured and their mechanical properties were compared with the sisal fiber composite (SFC) and kenaf fiber composite (KFC). Water absorption was carried out to find the moisture absorption capacity of the manufactured HC. HC provides better properties when compared with SFC and KFC. Hybrid composite is suitable for light weight automobile applications. [ABSTRACT FROM AUTHOR]

Hybrid laminates made using natural fibers have been finding applications in diverse fields such as automotive parts, building structures and sports goods. These laminates incorporate the benefits of the reinforcements used in constructions. The present work deals with the fabrication of hybrid laminate comprising of the natural fibers areca and kenaf in varying stacking sequences through the hand layup method. Epoxy resin (LY556) and hardener (HY951) are mixed in the ratio of 10:1 to prepare the matrix material. Six different hybrid laminates having five layers of areca and kenaf in different stacking sequences are produced. Two more laminates having either kenaf or areca in all the five layers and are produced to act as reference laminate. The prepared laminates are cut as per ASTM standards and subjected to tensile, compressive, flexural, impact and hardness tests in order to identify the properties of the fabricated laminates. The result shows that composite made with kenaf fiber as skin material and areca as core materials exhibit better tensile, flexural and hardness properties. Likewise, composites with outer layers of areca and core layers of kenaf fibers have high compressive and impact strength. The fractured surfaces after the mechanical tests are investigated through the Scanning Electron Microscope (SEM). [ABSTRACT FROM AUTHOR]

This study evaluates the thermal and mechanical properties of epoxy hybrid composites reinforced with date palm fiber (DPF) and kenaf fiber (KF) at various fiber loadings. Flexural properties, thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) of hybrid composites were reported. The flexural properties revealed the effect of fiber ratio on flexural strength and modulus; a higher kenaf ratio showed a higher flexural modulus. TGA revealed the effect of lignin present in the DPF, which affected the glass transition significantly. In DMA characterization, storage modulus revealed that 7DP3K showed higher modulus in the initial stage and had better glass transition than others. The loss modulus showed that the peak of 7DP3K had higher loss modulus, glass transition at a higher temperature, and wider relaxation period. Damping factor also showed that 7DP3K had peak at a higher temperature. The result showed that KF has positively impacted on DPF to improve the mechanical and thermal properties. The hybrid fibers in epoxy composites were effective in increasing the dynamic mechanical properties and flexural strength ascribed to the improved matrix/fiber bonding. The possible applications of the hybrid composites may be in building industry and automobiles. This study gives directions for further research on comparison of treated hybrid composites with untreated ones. [ABSTRACT FROM AUTHOR]

Hybrid composites have shown innumerable benefits to the research communities in terms of environmental friendliness and mechanical properties. This research study presents the mechanical characterization and moisture uptake of kenaf/pineapple leaf fiber‐reinforced polypropylene hybrid composites with several relative fiber ratios. A comparison was also made between nonhybrid and hybrid kenaf/pineapple leaf fiber‐reinforced composites to investigate the hybridization effect. In this work, the composite materials were fabricated via the hot compression technique. Mechanical tests were performed to obtain the tensile, flexural, and Charpy impact properties of nonhybrid and hybrid kenaf/pineapple leaf fiber‐based composites. The water absorption characteristics were then obtained by immersing the composite materials in the water until the saturation point was reached. The findings concluded that the mechanical properties and moisture uptake behaviors of the composites were improved through the hybridization. The hybrid composites with a relative fiber ratio of 25:75 were particularly promising with the improvement of 10.90% in tensile strength; 16.13% in flexural strength; and 6.80% in impact strength in both flatwise and edgewise orientations compared to nonhybrid kenaf‐based composites. Meanwhile, the diffusion coefficient of hybrid composites (25:75) was 56.12% lower than nonhybrid pineapple leaf fiber‐based composites. Thus, the results indeed demonstrated that the balance between mechanical properties and moisture sensitivity can be obtained through the hybridization of kenaf and pineapple leaf fiber in the composite materials. [ABSTRACT FROM AUTHOR]

This study investigated the mechanical and wear properties of heat-treated pultruded kenaf fiber-reinforced polyester composites (PKFPCs) using pultrusion technique. A total of three heat treatment temperatures (120, 140, and 170°C) of PKFPC and untreated PKFPC were produced and their performance was compared. Different sliding conditions and different heat treatment temperatures on PKFPC were tested according to the Taguchi orthogonal array design of experiment. The worn surfaces and transfer films produced were examined using scanning electron microscopy. The results showed that PKFPC with a 140°C heat treatment exhibited better wear performance than untreated PKFPC and PKFPC with 120 and 170°C heat treatments. The flexural strength and modulus of PKFPC increased after heat treatment. The counterface roughness and heat treatment temperature are the most significant factors affecting the wear performance of PKFPC. The optimum sliding conditions to achieve lowest wear and friction in the tested operating environment were determined. [ABSTRACT FROM AUTHOR]

The fiber-reinforcement is an attractive strategy to enhance composites under the green development concept. However, the poor dispersion/interactivity of natural fiber and most petroleum-based modification strategies impede development of fiber-reinforced environmental composites. In this study, we employed a soybean oil derivative as a multi-functional cross-linker that reacted with kenaf fiber (KF) to synergistically improve the soybean flour (SF)-based adhesive. The biobased cross-linker, phosphate and epoxy groups-containing soybean oil (PESO), was synthesized via phosphoric acid ring-opening reaction from epoxidized soybean oil in certain extent. To provide reaction sites, the KF was surface-coated by poly (tannic acid) (PTA) to obtain a PTA-coated KF (TKF). The PESO cross-linker, with the role of epoxy groups, constructed an interactive network skeleton with TKF and formed in situ cross-linking reactions with SF matrix. In addition, the incorporated phosphate groups of PESO gave rise to interactions with hydroxyl of TKF and polysaccharide of SF further stabilizing cross-linking network as confirmed by fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. As expected, compared to pristine SF adhesive, the modified adhesive showed a significant increment in wet shear strength by 236.4% and also exhibited a favorable thermal stability. We envisage that this design may provide a new avenue for developing high-performance fully sustainable biomass composites. [ABSTRACT FROM AUTHOR]

Kenaf fiber/high-density polyethylene/maleic anhydride (MA)-compatibilized composites were melt mixed in a twin-screw extruder and molded using injection molding machine. Physicothermal properties of the composites were studied at different percentages of compatibilizer contents using various techniques. The addition of 8% compatibilizer into 8.5 and 17.5 wt% fiber content improved the adhesion and tensile strength by 14.5% and 13.6%, respectively. Compatibilized samples exhibited higher peak load and fracture energy on impact testing compared to the samples without maleic anhydride compatibilizer. The effect of the addition of maleic anhydride compatibilizer on peak load and fracture energy was observed to be at its highest at 8%. Differential scanning calorimetric measurements revealed that the melting enthalpy and degree of crystallinity of composites increased with increasing compatibilizer content up to 8% and then decreased at 12% compatibilizer content. Dynamic mechanical analysis showed that the storage modulus of composites was increased, but the loss modulus and tangent delta were decreased after the addition of compatibilizer. This indicates that compatibilized composites produced have improved toughness and reduced stiffness. [ABSTRACT FROM AUTHOR]

Nowadays, fiber-reinforced composites have gained attention due to their improved potential for replacing the conventional materials in various applications. Kenaf fiber has been widely used as reinforcement in composites over the past few years which is a most attractive alternative due to its rapid growth at different climatic conditions and ensuring low cost; kenaf fiber has gained some attention to replacing the glass fiber composite and making it purely an eco-friendly composite. However, for enhancing its properties in different applications, an appropriate characterization is very important. Hence, many researches have been conducted in recent years, for the characterization of kenaf fiber and its composites. In this paper, a state-of-the-art review of these characterizations is presented. [ABSTRACT FROM AUTHOR]

The photocatalytic oxidation of various organic pollutants under UV irradiation can be enhanced by using titanium dioxide (TiO 2 ) photocatalyst. In this study, tubular TiO 2 nanostructures were synthesized in a single step by depositing titanium (IV) isopropoxide precursor on kenaf fibers used as a sacrificial template. In the calcination temperature range of 500–700 °C, the produced tubular TiO 2 predominantly contained the anatase phase. X-ray diffraction studies were performed to examine the crystallinity and crystallite size of the produced tubular TiO 2 , while its photocatalytic activity was determined by monitoring the degradation of methylene blue under ultraviolet irradiation. The obtained results showed that tubular TiO 2 formed at 500 °C exhibited the smallest crystallite size of 9.27 nm and fastest photocatalytic oxidation rate. [ABSTRACT FROM AUTHOR]

Natural fiber-reinforced polymer matrix composites have been increasingly used in automotive and other fields because of their good mechanical properties, low density, excellent damping properties and biodegradability. The objective of this work is to develop and characterize a high-performance lightweight kenaf fiber composite that is processed using unconventional processing methods, wet laid process followed with compression molding process. Kenaf fiber mats produced by wet laid process are stacked with high-density polyethylene films and compression molded into plates from which testing samples are prepared. The effects of fiber length, fiber content, and area density on the tensile properties are investigated. The composite samples with the best tensile properties are also evaluated in its flexural, compression, impact, and fire resistance performance. The processing–structure–property relations of the developed kenaf fiber high-density polyethylene composite are systematically studied, which can be broadly applied to other natural fiber composites. [ABSTRACT FROM AUTHOR]

In this study, chemically functionalized reinforcements, such as Kenaf fiber (KF) and multi-walled carbon nanotubes (MWCNTs), are used to enhance the crystallinity, mechanical properties and heat resistance of polylactic acid (PLA) composites. The functionalized KF and MWCNTs evidence excellent compatibility in the PLA matrix through the generation of chemical bonding, and a transcrystalline structure is generated around the reinforcements, thereby significantly improving the physical properties. The DSC analysis reveals that functionalized KF can speed up crystalline growth and increase the crystalline content. The annealing treatment further drives the PLA re-crystalization and enhances crystallinity, according to the DSC results. Moreover, the Avrami equation shows that the functionalized KF and MWCNTs are helpful in turning the PLA crystallinity from a 3-dimensional bulk (or sphere) structure into a 2-dimensional sheet structure. [ABSTRACT FROM AUTHOR]

• Sustainable geopolymer concrete using FA and GGBS, with the addition of kenaf fiber was produced. • Effects of kenaf fiber length and volume fraction on the engineering properties of geopolymer concrete were studied. • Mechanical properties of the composites were predicted via Surface Response Approach. Sustainable construction materials are in needs to reduce CO 2 emissions in the environment. Geopolymer being an emergent sustainable construction material had been extensively studied. However, its brittleness is still the main issue to be overcome. Hence, in this research, natural kenaf fiber (KF) as environmental-friendly low-cost material is introduced to enhance the overall quality of the geopolymer. This study introduces a potential sustainable construction material called Kenaf Fiber-Reinforced Geopolymer Concrete (KFRGC) which is studied via experimental tests and statistical modelling. The effects of 20 mm to 40 mm lengths and 0.75 % to 1.5 % volume fractions of kenaf fibers on the engineering properties of KFRGC were measured. The splitting tensile strength and flexural strength of KFRGC were observed to improve without any significant increase in the compressive strength. At 28 days of curing age, KFRGC prepared with 30 mm long, and 1.25 % volume fraction of fiber showed a 20 % and 27 % increase in splitting tensile strength and flexural strength, respectively, compared to the plain geopolymer. Furthermore, the model predicted and experimental results closely matched (less than 5 % inaccuracy). It is concluded that natural KF-included concrete can be used as an eco-friendly and sustainable building material. However, the durability aspect must be studied before it can be commercially used. [ABSTRACT FROM AUTHOR]

• Composites were made from polyurethane and natural kenaf fiber. • Sound absorption was optimized using CCD-RSM approach. • Effect of fiber length and added fiber weight was investigated. • A quadratic model was proposed for sound absorption prediction. • Hypric composite showed superior acoustic performance compared to neat PU foam. • JCA model have a good agreement with the experimental data. In this study, hybrid composites made of polyurethane (PU) matrix and natural kenaf fiber filler were designed and fabricated. The Response Surface Methodology (RSM) optimization approach coupled with a Central Composite Design (CCD) was used to design the experiments and optimize the parameters affecting the acoustic performance of the samples in the low and mid-frequency ranges. The acoustic performance of the samples was investigated using the impedance tube method. Additionally, the acoustic performance was predicted using a developed Quadratic model as well as the Delany-Bazley (DB) and Johnson-Champoux-Allard (JCA) models. The results showed that the acoustic absorption of neat PU foam is remarkably improved at all frequencies with the addition of kenaf fibers as the filler. It was found that the acoustic performance of the composite samples is optimal when the added amount of kenaf fibers to the polymer matrix and fiber length are 1.2 wt% and 8 mm, respectively. The sound absorption average (SAA) of the optimized composite and neat PU foam was calculated as 0.65 and 0.48, respectively i.e., an increase of 35.4 %. The Quadratic model showed very high accuracy for the prediction of the SAA of the optimized sample. The JCA model provided higher accuracy for the prediction of the frequency-dependent sound absorption coefficient of the composites as compared with the DB model. [ABSTRACT FROM AUTHOR]

Indium zinc oxide (IZO) was successfully deposited onto kenaf fibers (KFs) by a dip-coating method. The novel aspect of this study was the investigation of the electrical conductivity of the resulting indium zinc oxide-modified kenaf fiber (KF-IZO) by emphasizing on its morphology and the dipping rate used for dip-coating. KF was alkalized using a 5% sodium hydroxide (NaOH) solution. The dipping rate was varied from 1 to 30 mm/s. KF-IZO was then annealed at a temperature of 150 °C for 4 h. A modified four-probe method employing a copper metal attachment plate was used to evaluate the electrical properties of KF-IZO. A dipping rate of 5 mm/s, which yielded the highest electrical conductivity of 11.81 S/mm, was found to be optimum. Scanning Electron Microscope/Energy Dispersive Using X-Ray (SEM-EDX) analysis of KF-IZO revealed that the IZO film was uniformly coated on the KF substrates, and no significant thermal damage was observed. KF-IZO showed the potential to be used in smart textiles, electrostatic discharge protection, and as a reinforcement in composites. [ABSTRACT FROM AUTHOR]

Biodegradable poly(butylene succinate-co-lactate) (PBSL)/starch blends that contain various amounts of starch were prepared. In addition, luffa fiber (LF) and kenaf fiber (KF) were incorporated, individually, into PBSL/starch (70/30) blend to achieve biocomposites. The LF and KF were treated with NaOH (aq) prior to their addition to the blend. The Young's modulus and flexural modulus of PBSL increased with the addition of starch and increased further after the formation of the biocomposites. The highest Young's modulus increment, which was found in the KF-added system, was up to a 2.2-fold increase compared with neat PBSL. The tensile/flexural/impact strength of PBSL declined after the formation of the blends. With the further addition of LF/KF, the said properties leveled off. The blends exhibited higher complex viscosity and dynamic storage modulus in the melt state than the neat PBSL, and the values further increased in the biocomposites. The crystallization temperature of PBSL slightly decreased in the blends. By contrast, the biocomposites showed an increment in PBSL crystallization temperature, from 73.0 °C (PBSL) to 75.3 °C (KF-added composite), thereby confirming the surface nucleation effect of LF/KF. The blends showed a higher degree of water absorption than PBSL. The formation of biocomposites led to an even higher degree of water absorption. The current approach of including LF/KF in the PBSL/starch blend to enhance the rigidity and biodegradability was advantageous in expanding the applications of PBSL. [ABSTRACT FROM AUTHOR]

The demand on wind energy application will continue to increase as fossil fuel prices keep increasing and the reservoir keeps decreasing. In wind energy, wind turbine application should be properly selected. The material selection for turbine blade fabrication is highlighted as well in recent research. For green material application, the usage of natural fiber reinforced composite, especially kenaf fiber, in the fabrication of wind turbines needs to be given due attention. Woven and unwoven kenaf fiber is employed to fabricate composite plates which replicate the simple turbine blade model. At the same time, Macro Fiber Composite (MFC) is attached to the kenaf plates for micro energy harvester purposes. There are two methods to attach the MFC used in this study which are surface bonded and embedding into the plate. In order to investigate the effects of bonding MFC technique, modal Testing analysis and Taguchi method is employed. It is found out that the damping percentage of both woven and unwoven kenaf plates increase at 100% and 50% respectively when bonded with MFC on their surfaces. Bonded technique is suggested as the most influenced factor in micro energy harvesting at the vibration range of 20 to 60 Hz. It summarized that, the kenaf woven type, the distance from structure neutral axis, the stiffness of structure, the excitation vibration and the neutral frequency of a structure are highlighted as the factors influencing the performance of micro energy harvester as well. [ABSTRACT FROM AUTHOR]

Biomimetic hydroxyapatite (HA) growth on mercerized kenaf fiber (KF) was achieved by immersion in a simulated body fluid (SBF) solution with the addition of a chelating agent. An electron micrograph revealed uniform HA layers on the KF within 14 days of immersion with significant vibrational peaks of HA components. The tensile tests showed no significant drops in the unit break of the modified fibers. This new bone-like apatite coating on KF can be useful in the field of bone tissue engineering. The key motivation for this new approach was that it utilizes the abundantly available kenaf plant resource as the biobased template. [ABSTRACT FROM AUTHOR]

The primary aim of this paper is to analyze the fiber length retention capacity of extrusion and injection molding processes for short and long kenaf fiber reinforced polypropylene composites. The composites were manufactured by adding maleic anhydride grafted polypropylene (MAPP) and an antioxidant (Irganox) using twin-screw extrusion and injection molding processes. A higher level of fiber attrition rate was observed during the twin-screw compounding compared to that in the injection molding. During high-temperature shear mixing, both processes caused a reduction in fiber length below the calculated critical fiber length along with considerable fiber damage. The mechanical and thermal properties of the resultant composites were subsequently characterized. Cone calorimeter tests demonstrated that the peak heat release rate for the kenaf fiber composites (30 wt.%) was reduced by 37% compared to pure polypropylene (PP). In the UL-94V tests, the presence of lignin in kenaf reduced the dripping time considerably, which further led to the formation of char residue after burning. Although the fiber length obtained was below the critical fiber length under high shear processing (twin-screw compounding and injection molding), effective fiber dispersion, orientation and opening led to significantly improved mechanical performance of the PP/kenaf composites, irrespective of the initial fiber length. [ABSTRACT FROM AUTHOR]

This paper describes the preparation of poly(vinyl alcohol)/kenaf fiber (PVOH/KF) composites with entrapped urea. The major FTIR peaks of these composites could be identified. These composites are intended for agricultural applications as biodegradable mulches and could be potential carrier materials for fertilizer. The water solubility, release behavior, chemical properties, and thermal stability of the composites were evaluated. The composites lost 25% of their weight after 7 days in water. In a wet environment, urea was released from the composites through its dissolution in water, and around 57% of the urea was released from the composites in 24 h; Thermagravimetric analysis showed that these composites were stable up 150 ?C. These composites would be able to withstand rain and protect seedlings from the sun when applied in the field as mulches. For around three to four weeks, these biobased mulches could slowly disintegrate as the PVOH binder was gradually dissolved by moisture, releasing the kenaf fibers to serve as soil fertilizer without leaving any undegradable waste for disposal. Hence, they would not pose any risks to the land or biological systems. [ABSTRACT FROM AUTHOR]

Kenaf is an economically viable and ecologically friendly cellulose source. It can be used in the textile, paper, and bio-energy industries, but it has not been effectively developed and utilized because of degumming problems. To effectively take advantage of kenaf resources, to satisfy the growing demand for natural fiber, and to provide support for other fiber material degumming, steam explosion (STEX) pretreatment followed by alkali-oxygen treatment was studied. The effect of pressure on the properties of kenaf during the STEX treatment was studied, and the optimal degumming process for kenaf was selected. Results showed that STEX pretreatment removed pectin and part of the hemicellulose. Carbohydrates (cellulose and hemicellulose) could be degraded via high pressure treatment. The residual gum content and the fineness of the kenaf fiber after the alkali-oxygen treatment were good enough for textile production. High pressure was found not to be a key factor influencing the degumming process. Low pressure STEX (0.5 MPa) and alkalioxygen treatment was judged to be an efficient method for degumming kenaf fibers. [ABSTRACT FROM AUTHOR]

The effect of external pressure during the inorganic nanoparticle impregnation (INI) process on the content of impregnated calcium carbonate nanoparticles in kenaf fibers was investigated. The in situ INI process was used to introduce the calcium carbonate nanoparticles into the fibers. The retted kenaf fibers were immersed into calcium chloride solution with various pressures and then treated by sodium carbonate solution to produce calcium carbonate nanoparticles impregnated kenaf fibers. It was found that the calcium carbonate content increased by 76.7% when a 13.8 MPa external pressure was applied during the calcium chloride immersing process. The impregnation efficiency for reducing the fiber porosity was increased by 70.1%. The mechanical properties, including modulus of elasticity, modulus of rupture and tensile strength of the INI-treated fiber/polyester composites were enhanced by 43%, 79% and 86% compared with the un-treated fiber/polyester composites. [ABSTRACT FROM AUTHOR]