Search

The non-biodegradable nature of synthetic composites has driven the composite manufacturing industry and researchers to explore biodegradable materials. To utilize these biodegradable composites, which often have compromised properties, in static and dynamic load-bearing applications as alternatives to synthetic composites, a comprehensive comparison is essential. This study compares the buckling, vibration, and deflection characteristics of four types of honeycomb sandwich composites: glass fiber-reinforced epoxy (GFRE), multiwalled carbon nanotube (MWCNT)-reinforced GFRE, hemp fiber-reinforced epoxy (HFRE), and MWCNT-reinforced HFRE with MWCNT/GFRE skin. MWCNTs were added to both GFRE and HFRE honeycombs to enhance core characteristics. The effects of adding MWCNTs to the skins of these sandwich composites on all characteristics were investigated numerically. The elastic constants required for the numerical simulations were determined using the alternative dynamic approach. A finite element model based on higher-order deformation theory was used to perform the simulations under various boundary conditions. The findings reveal that the HFRE honeycomb sandwich composite with added MWCNTs exhibits compromised but competitive static and dynamic characteristics compared to the GFRE honeycomb sandwich composite with added MWCNTs. Additionally, the inclusion of MWCNTs in the skin results in superior performance for the HFRE honeycomb sandwich compared to the GFRE counterpart. This study demonstrates the potential of MWCNT-reinforced biodegradable composites in applications traditionally dominated by synthetic composites. [ABSTRACT FROM AUTHOR]

In this study, tests were conducted to examine the morphological, mechanical, and wetting properties of thermoplastic composites using banana fiber (BF) an agro-residue as a filler. Plasma-treated polyethylene (PPE) was used as the matrix, and compression molding technique was used for composite preparation. Treated and untreated polyethylene (UPE) banana fiber composites were compared in terms of the interfacial adhesion between the fiber and the matrix. Fibers were added in varying amount (10, 20, 30, and 40 by weight %) into the polymer to investigate the fiber-matrix interaction in each case and also to optimize the composition that would yield improved properties. Morphological properties were studied using scanning electron microscopic (SEM) studies, surface wettability was studied using the contact angle method and FTIR analysis was used to confirm the effectiveness of the functionalization. SEM analysis showed that PPE-BF composites have better interfacial adhesion between the polymer and fiber as compared to UPE-BF composites. Also, PPE-BF showed a maximum of 6% and 25% increment in tensile strength and Young's modulus. Wettability studies showed that contact angle values got decreased from 93° (UPE-BF20) to 77° (PPE-BF20), which proves the effectiveness of plasma treatment through incorporation of new functionalization (polar groups) on the surface of the polymer in treated composites, and also which shows how the treatment enhanced the interfacial bonding between polymer and fiber. [ABSTRACT FROM AUTHOR]

The study developed an eco-friendly composite material using silane-treated coconut shell powder, areca nut powder, and corn husk fiber in epoxy. The principal aim of this research work is to develop an eco-friendly composite using biomass wastes. The fiber and filler were silane surface treated using 3-aminopropyltriethoxysilane and the composites were developed using hand layup method. The composites were further tested for load-bearing and tribological properties in accordance with ASTM standards. According to results, composite CHAE3 exhibited high tensile strength (88.88 MPa), flexural strength (175.89 MPa), impact energy (5.3 J), hardness (85.8 Shore-D), and fatigue resistance. CHAE5 showed high thermal stability (TG%, 94% at 384 °C), thermal conductivity (0.209 W/mK), water absorption (1.94%), CoF (0.28), and low wear loss (0.07 g). According to the ANOVA results, since p value < α, H0 is rejected. Some of the groups' averages consider being not equal. In other words, the difference between the sample averages of some groups is big enough to be statistically significant. Enhanced performance of CHAE3 is attributed to optimized composition, effective filler dispersion, and enhanced interfacial bonding, revealed by SEM analysis, suggesting potential applications in automotive, construction, aerospace, defense, and sports. [ABSTRACT FROM AUTHOR]

The agriculture plant Cannabis sativa (hemp) is used to create composite panels for the automotive industry because of its high strength-to-weight ratio. The purpose of this research is to investigate the effect of fiber length (10–30 mm), content (10–30 wt%), and alkali treatment (3%) on the mechanical properties of these hemp/vinyl ester composites. Tensile, flexural, impact, and hardness tests, dynamic mechanical analysis, as well as tribology behavior, were performed on the untreated and alkali-treated hemp/vinyl ester composites. The band around 3100–3700 cm−1 in NaOH-treated hemp-reinforced composites can be attributed to hydrogen-bonded OH stretching vibrations from the chemically bonded OH groups of the cellulose structure. So, the crystallinity of NaOH-treated hemp was increased when compared with untreated hemp fiber composites. The mechanical properties were increased by increasing the fiber content to 30 wt% and the length to 30 mm. Because of the alkali treatment, the transition peak occurred in the range of 73 to 135 °C for untreated and 80 to 1350 °C for alkali-treated composites. In tribological experiments, the applied load influenced the coefficient of friction (COF), followed by its fiber content. However, the synergistic effect of sliding distance and fiber length has resulted in a decreased wear rate. These findings suggest that hemp fiber has the potential to be employed as a reinforcing material in a variety of structural and non-structural applications. [ABSTRACT FROM AUTHOR]

Excessive deforestation caused by the demand for wood as a primary raw material in papermaking has a direct and detrimental impact on the environment. Therefore, it is crucial to explore alternative natural resources for paper production. Global surveys indicate that the juice manufacturing industry generates a substantial amount of waste, posing significant challenges for waste management. A recent investigation has revealed that pineapple (Ananas comosus) crown waste (PCW) could serve as a viable source of fibrous raw material. Findings demonstrated that PCW contains approximately 74% holocellulose (cellulose + hemicelluloses), comparable to rice straw and hardwood However, PCW has a lower lignin content of 15% compared to the 25.7% found in hardwood. The process of pulping PCW requires a lower chemical demand compared to wheat straw for the production of similar kappa pulp. When using a 15% chemical dose, high-strength paper made from soda pulp was achieved. Beyond this dose, the paper's strength decreased. However, in the kraft process, the strength increased up to a 20% chemical dose. The tear index of PCW pulp-based paper was 64% higher than that of wheat straw pulp in the soda pulp process and 60% higher in the kraft pulp process. Similarly, the burst index of PCW pulp-based paper was approximately 76% and 72% higher than soda and kraft wheat straw pulp, respectively. Therefore, the utilization of PCW not only resolves issues related to industrial waste management but also mitigates the raw material crisis faced by the papermaking industry. [ABSTRACT FROM AUTHOR]

This research explores the scope of natural fibers for prosthetic socket application. A variety of conditions including maladies, accidents, and genetic disorders, necessitate the adoption of prosthetic organs. The human body undergoes significant physiological changes over time due to factors such as growth, weight fluctuations, and the periodic replacement and adjustment of appendages. In this study, biocomposite materials are fabricated using vacuum bag technology, with sisal fibers reinforced in vinyl ester at five different weight percentages: 0%, 5%, 10%, 15%, and 20%. Mechanical characteristics are determined through destructive testing, including flexural, tensile, impact strength, and hardness measurements according to ASTM standards. Scanning electron microscopy (SEM) analysis is employed to assess factrography and bonding properties. Results indicate that the biocomposite with 15% sisal reinforcement exhibited superior tensile and impact resistance compared to other compositions and matrices. However, at the expense of impact strength, the 20% sisal-reinforced vinyl ester increased hardness and flexural strength by 47% and 27%, respectively. This research aims to expand natural fibers and their utility in biomaterial applications, outlining points for elaboration and enhancement in this field, along with addressing associated challenges. [ABSTRACT FROM AUTHOR]

The rhizomes of the wild turmeric plant are harvested while the aerial part is discarded as waste. The current study aims to extract fibers (WTPF) from the petiole portion of the wild turmeric plant by manual (mechanical) retting using metal comb. The fiber extraction is carried out at two stages: the first extraction yielded long and strong fibers (WTPF-1) ranging in length between 20 and 40 cm and the second extraction from the residual biomass yielded comparatively shorter fibers (WTPF-2) ranging in length between 1 and 5 cm. The extracted fibers are evaluated for physical, chemical, thermal, structural and morphological properties. The diameter of both the fibers is observed to be 20 µm and the tensile strength is 2.17 Mpa. The fibers exhibited significant difference in their properties, say the hemi-cellulose content, elongation at break, density, young's modulus while the cellulose, lignin, wax, pectin, ash and moisture content did not vary much. Based on the properties, the WTPF fiber has potential application in technical textiles field as it could be made into non-wovens and composites. [ABSTRACT FROM AUTHOR]

A sufficient understanding of the failure mechanisms that govern the mechanical behavior and failure modes of natural fiber composites is essential. In this regard, acoustic emission (AE) is a potential technique to monitor the mechanical behaviour and to provide the required information about the failure mechanism of natural fiber-reinforced polymer composites. The purpose and novelty of this study is to investigate for first time, the fracture behaviour of banana/ramie/epoxy composites under a 3-point bending test. During the test procedure, the AE parameters were recorded to evaluate the crack growth from the initial crack to the final fracture of the specimen and to determine the damage locations. AE parameters, such as amplitude, frequency, cumulative hits, and AE energy distributions, were used to identify the failure mechanisms associated with matrix cracking, delamination, fiber-matrix debonding, and fiber breakage. Based on these findings, the cumulative effect of AE events (counts/hits) represents the stress risers that cause failure in the specimen. Because natural fiber composites are brittle materials, they weaken when subjected to tensile loads. For this reason, the outermost bottom layer experienced more failure than the compressive layers during the bending of the specimen. The failure modes were studied using scanning electron microscopy. It was observed from the AE activity that the stress level at the crack initiation is 10–15% higher than the stress magnitude at the fracture stage. [ABSTRACT FROM AUTHOR]

Highlights This study explores the mechanical, thermal, and morphological behavior of polylactic acid (PLA) composites reinforced with flax fiber (FF) during recycling. The influence of the addition of bio‐filler (w/w) on the recycling of FF/PLA composites was also analyzed. The recycling influencing the performance of FF/PLA composite was compared with that of halloysite nanotube (HNT)/FF‐PLA composites. The FF/PLA and HNT/FF‐PLA composited were fabricated by injection molding subjected to multiple recycling. The tensile and flexural properties of both composites were assessed after each recycling. Fractured specimens of the recycled samples were analyzed using a scanning electron microscope to study their morphology. Thermal degradation was evaluated through thermogravimetric analysis of the recycled FF/PLA and HNT/FF‐PLA samples. After the fifth recycling process, the HNT/FF‐PLA composite experienced a decrease in tensile strength by 75.01% and flexural strength by 59.88%. The performance of FF/PLA and HNT/FF‐PLA composites was detrimentally affected due to the thermal deterioration of flax fiber and the subsequent decrease in fiber length resulting from repeated reprocessing. The highest degradation for non‐recycled FF/PLA and HNT/FF‐PLA samples occurred at temperatures of 354°C and 347°C, respectively. Whereas the maximum degradation for recycled cellulose (RC)‐5 (fifth recycled) FF/PLA and HNT/FF‐PLA composite occurred at 328 and 327°C. Adding 1% HNT increased the tensile and flexural strength by 12.5% and 1.79%. The behavior of the composites was affected by the thermal degradation of FF. The maximum degradation of RC‐5 FF/PLA composite occurred at 327°C. The maximum degradation for RC‐5 HNT/FF‐PLA composite was noticed at 328°C. [ABSTRACT FROM AUTHOR]

This study evaluated the influence of adding borosilicate residue (BS) as a flame retardant in polypropylene (PP) and natural fiber composites. The natural fibers used in this study come from the residue of the carpet industry, which is composed of PP and jute fibers (JT), while the PP used as the polymer matrix is postindustrial recycled material. The composites were produced by corotational twin‐screw extrusion and injection molding to obtain the test specimens. A coating process was carried out to add the water‐soluble fraction of BS to the surface of the compositions that did not receive it through incorporation during processing. To characterize the composites, flammability tests, thermogravimetric analysis (TGA), tensile strength test, and morphological analysis by scanning electron microscope (SEM) were performed. The addition of only 2 wt% BS content induces an increase in thermal stability of 32 and 109°C for composites with and without natural fibers, respectively. The addiction of 20 wt% BS elevates the elastic modulus up to 27% of the composites with and without natural fibers. The BS characterization indicates that it could be applied as a flame retardant when applied as coating methods using the water‐soluble fraction of BS, reducing the burning rate up to 92%. Flammability results are similar for formulations with and without natural fibers, indicating that the natural fibers did not influence the proposed flame retardant. The findings suggest that BS coating is a potential solution to improve the properties of natural fiber‐reinforced polymer composites while also promoting waste recycling. This approach produces composites with improved flammability, thermal stability, and mechanical properties, making them suitable for various end applications. [ABSTRACT FROM AUTHOR]

There is a growing trend in the construction industry to adopt environmentally friendly practices, and innovative materials are becoming increasingly popular. Within the scope of this paper, the potential of natural fiber-reinforced cement composites (NFRCs) as an environmentally friendly building material is examined. This work introduces plant fiber aspects such as micromorphology, primary components, physical and mechanical properties, chemical components, thermal properties, and degradation mechanisms in cement composites. It explores how plant fibers affect concrete's mechanical performance, durability, and thermal qualities. It is responsible for increasing permeability and decreasing durability in concrete material because plant fibers have porosity and a weak interface. The purpose of this in-depth investigation is to investigate the features, sustainability (social, environmental, and economical) performance, and applications of NFRCs, with a particular focus on environmentally responsible innovation and potential future applications. The exhaustive study also addresses the difficulties associated with attaining the highest possible level of compatibility between fibers and matrixes. The physical and chemical treatments of natural fibers in cement components give more resistance to aging by reducing water absorption and increasing roughness at the surface. It is also possible to reduce the effect of alkalinity of the cement mixture through optimization of the binder component and curing regimes, which retard the breakdown of natural fibers. The purpose of this study is to present a summary of existing research, with a particular emphasis on the benefits, drawbacks, and prospective ways in which NFRCs could potentially improve throughout the construction industry in the future. [ABSTRACT FROM AUTHOR]

The growing demand for cotton and the low production rate required to meet global demands have encouraged viscose manufacturing from renewable sources. This work develops a sustainable method to extract viscose fibers (cellulosic‐based precursor) from jute, a renewable resource. Jute fiber is the second largest fiber crop in southern Asia, which contains 65%–70% cellulose and contributes to environmental benefits such as oxygen production, carbon dioxide emission, and heavy metal absorption during harvesting. The treated jute fiber was modified to regenerated cellulose (viscose), as confirmed by different characterizations. The Fourier‐transform infrared spectroscopy (FTIR) test 1423, 1365, 1033, and 1021 cm−1 represented that modified jute fiber resembled viscose fiber, and TGA attributed the thermal stability of glass transition below 100°C and thermal degradation to jute viscose fiber. XRD analysis provides a crystal index of 91.79% of viscose from jute fiber, which is higher than the 76.06% crystal index of raw jute. Here, SEM and physiomechanical properties were also characterized by raw jute and viscose from jute fiber. [ABSTRACT FROM AUTHOR]

The conversion of waste into value‐added products is critical to long‐term sustainability as waste disposal costs, landfilling space, and climate change would be reduced. Research and production industries investigate the possible use of natural fibers as a substitute for fossil fuels. Natural fiber‐reinforced polymer composites' physical and mechanical properties can be altered by natural fiber treatment, and the treatment choice relies on the desired properties and performance. In addition to cost‐profitability, environmental effects, and required performance, composites can be designed based on the product conditions. Disadvantages such as incompatibility of the hydrophilic natural fiber reinforcements with the hydrophobic polymer matrix often result in the tendency of the composite to have high moisture absorption, poor thermal stability, crystallinity, and mechanical strength. These factors critically impair the performance of the natural fibers as reinforcements in polymer composites, hence resulting in less‐favourable mechanical and physical properties. Physical, chemical, and biological treatments were examined to determine their effect on the durability and thermal, physical, and mechanical properties. It was observed that plasma treatment for bamboo fibers resulted in interfibral spaces and anchoring mechanisms between the resin and fibers, leading to increased load transfer. Chemical treatment at various concentrations improved the surface smoothness. The best mechanical, physical, thermal, and chemical properties for application as reinforcement in polymer composites were obtained at 6% for alkali treatments. Enzymatic treatment showed a significant impact on the impact and flexural strength of the composites. Factors such as duration, concentration, and extent of treatment need to be established for effective treatment, as prolonged treatments may damage the NFs' properties. This review comprehensively highlights the potential utilization of current natural fiber treatment methods for the potential of natural fibers as value‐added products for construction materials, considering their economical affordability, production of lightweight materials, sustainability, utilization of readily available waste material, and nature preservation. Furthermore, the three natural fiber treatment approaches for improving fiber‐matrix adhesion are discussed. The physical and mechanical properties of composites are highlighted, which aids in evaluating suitability for construction materials. [ABSTRACT FROM AUTHOR]

Expansive soils, prone to significant volume changes with moisture fluctuations, challenge engineering infrastructure due to their swelling and shrinking. Traditional stabilization methods, including mechanical and chemical treatments, often have high material and environmental costs. This study explores fibrous by-products of flax processing, a sustainable alternative, for reinforcing expansive clay soil. Derived from the Linum usitatissimum plant, flax fibers offer favorable mechanical properties and environmental benefits. The research evaluates the impact of flax tow (FT) reinforcement on enhancing soil strength and reducing cracking. The results reveal that incorporating up to 0.6% randomly distributed FTs, consisting of technical flax fibers and shives, significantly improves soil properties. The unconfined compressive strength (UCS) increased by 29%, with 0.6% FT content, reaching 525 kPa, compared to unreinforced soil and further flax tow additions, which led to a decrease in UCS. This reduction is attributed to diminished soil–fiber interactions and increased fiber clustering. Additionally, flax tows effectively reduce soil cracking. The crack length density (CLD) decreased by 6% with 0.4% FTs, and higher concentrations led to increased cracking. The crack index factor (CIF) decreased by 71% with 0.4% flax tows but increased with higher FT concentrations. Flax tows enhance soil strength and reduce cracking while maintaining economic and environmental efficiency, offering a viable solution for stabilizing expansive clays in geotechnical applications. [ABSTRACT FROM AUTHOR]

In the current work, the dynamic and buckling properties of hybrid fiber-reinforced polymer composite beams are investigated. The hybrid composite beam is made of polyester matrix, carbon fiber, and jute fiber. The mechanical characteristics of carbon/jute/polyester composites were examined using ASTM standards. Experimental dynamic analysis was performed on jute, carbon, and hybrid carbon/jute composite beams. The validity of a finite element (FE) model based on higher-order theory was examined, and it exhibits outstanding agreement for composite beams when compared to experiments and literature. The hybrid composite beams have a considerable impact on structural stiffness when compared to neat jute/polyester composite beams. In this work, the effects of end conditions, taper angles, and composite layers are also investigated in relation to the dynamic and buckling properties of uniform and tapered hybrid carbon/jute/polyester composite beams. The findings imply that hybrid composites can be a superior substitute material for automotive applications. [ABSTRACT FROM AUTHOR]

This paper presents a comparative study on the effect of two local Libyan grasses, Stipa tenacissima (locally known as Halfa) and Retama raetam (locally known as R'tem) on the mechanical properties of styrene-butadiene rubber composites (SBR). For this purpose, the effect of filler type and content (10, 20, 30 and 40 wt%) on the mechanical properties of the composites including stress at break, elongation at break, impact strength and microhardness were evaluated. The stress at break of SBR increased only with the addition of 20 wt% and 30 wt% of Halfa. The highest value of stress at break was obtained by composites made with 20 wt% Halfa content. The elongation at break was significantly decreased with the addition of Halfa and R'tem. Generally, the elongation at break of the composites made with R'tem was slightly higher than that of composites made with Halfa. On the other hand, the addition of Halfa resulted in composites with relatively higher impact properties. The impact strength of these composites was increased with increasing the Halfa content up to 30 wt% after which it was decreased noticeably. However, the impact strength of composites made with R'tem did not follow a clear path with increasing R'tem content. Furthermore, the incorporation of Halfa and R'tem resulted in a significant increase in the hardness properties of the composites. R'tem showed to produce composites with higher hardness compared to those made with Halfa. Composites made with Halfa possess better toughness and ductility to a certain degree in comparison to composites made with R'tem. Although, Halfa appears to be relatively better than R'tem in reinforcing SBR, both fillers appeared to be good candidate filler to produce low cost and density polymer composites with acceptable mechanical properties. [ABSTRACT FROM AUTHOR]

With growing environmental concerns and the depletion of oil reserves, the need to replace synthetic fibres with sustainable alternatives in composite materials has become increasingly urgent. This study investigates the potential of Leptadenia pyrotechnica fibre as a sustainable reinforcement material in hybrid composites alongside E-glass fibres. The primary objectives are to assess these hybrid composites' mechanical properties, structural integrity, and performance. To achieve this, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were employed to analyze the microstructure and chemical composition of the composites. At the same time, mechanical testing focused on properties such as flexural strength and compression strength. Inter-laminar failure analysis evaluated how well the fibres bonded within the composite structure. The results demonstrate that Leptadenia pyrotechnica fibres significantly enhance flexural strength and offer mechanical properties suitable for diverse industrial applications. This indicates their potential as a sustainable alternative to traditional natural fibres. The findings suggest that incorporating Leptadenia pyrotechnica in hybrid composites could lead to the development of more environmentally friendly and durable materials. This work highlights the significance of using sustainable, naturally sourced fibres in composite materials, offering a promising path for further exploration in industrial applications. [ABSTRACT FROM AUTHOR]

The automotive industry is under significant pressure to curb greenhouse gas emissions from their products as the negative impacts on the environment are increasingly apparent. As such, there is significant interest within the industry to develop low-carbon footprint materials. Natural fiber composites are therefore appealing due to both their decreased carbon footprint, as well as their relatively low cost, low density, and beneficial acoustic properties. This research specifically focuses on the use of paper fibers as composite reinforcements. Paper offers additional benefits over other natural fiber types in that it is globally available, does not compete with food resources, and has well-established quality control techniques. The goal of this work was to study the manufacturing of polypropylene (PP)-paper fiber composites using a hybrid wet-lay/compression molding processing. The processing parameters studied included molding temperature, molding duration, and molding pressure. Paper composites were characterized for properties including flexural strength, impact strength, and water uptake rate. An optimal set of processing parameters was identified in which cycle time and energy inputs (e.g. temperature and pressure) were minimized while retaining desired material properties. [ABSTRACT FROM AUTHOR]

Research on the sustainable production of building materials has been increasing from time to time. The construction industry is one of the sectors that leads to the depletion of significant amounts of nonrenewable resources, such as minerals. The ecosystem is deteriorated, and carbon dioxide (CO2) emissions are enormous in the environment due to the use of fossil fuel-based materials. The purpose of this paper is to review the use of plant fibers (hereafter NF) for reinforcement in cementitious concrete. Concrete, plant fibers, their chemical nature, and characteristics are highlighted in an overview. The most important issues in NF-concrete compatibility were discussed, which could provide research opportunities. Modification of NFs and the cement matrix are examined as methods for improving compatibility and degradation. Moreover, the properties and longevity of cementitious materials that are reinforced with natural fibers are also examined. Finally, the review emphasizes the significant research gaps and future research prospects identified in the reviewed papers. [ABSTRACT FROM AUTHOR]

The use of sanitary napkins during menstruation is inevitable. However, they pose a menace to the environment because of the associated non-biodegradability. Conventional sanitary napkins are composed of around 90% plastic, which goes to landfill and remains there for centuries leading to an increased carbon footprint. A study conducted on major brands of sanitary napkins in India revealed that the presence of various phthalate groups harms neurological, cardiovascular, and reproductive systems in women and volatile organic compounds show harmful neurological effects including paralysis and memory loss. To overcome this environmental mayhem and severe pathological effects, various approaches have been undertaken by researchers and government authorities. Plant-based alternatives aid the dire need to manufacture sanitary napkins which can decompose and leave no threat to biodiversity. The use of organic materials like cotton, jute, bamboo, banana fibers, and neem leaves in making sanitary napkins holds magnanimous potential. The utilization of sansevieria and water hyacinth to produce sanitary napkins served the dual purpose of recreating life in water bodies and providing financial independency to the local women in Africa. Leftovers of many natural products during their processing end up creating an increased amount of waste material. Incorporating the industrial waste in the absorbent layer to generate eco-friendly napkins retains the sustainable tripod and also reduces the cost which will make napkins affordable by women of every class in society. This review sheds light on the grave issue of disposal and non-biodegradability of currently used marketed sanitary napkins, various biodegradable approaches and their importance over conventional sanitary napkins, that can be adopted to overcome this environmental problem. [ABSTRACT FROM AUTHOR]

Highlights The demand for natural fiber‐reinforced polymer composites is increasing in the automotive industry, and Mexican blue‐gave fiber (AF) is getting attention from automakers. Quantitative characterization of the tensile behavior of AF allows for a better ascertain of fiber performance. This work developed a model to study the elastoplastic behavior of AF prior and after its incorporation within a thermoplastic matrix. Finite element predictions showed excellent agreement with both theoretical and experimental values from literature. It was revealed that the increase in the fiber aspect ratio hastens the interaction between nearby defects within the fiber with earlier coalescence of voids, and ultimately fosters the loss of both fiber ductility and load carrying capacity. Moreover, the preponderant character of the damage in AF is controlled by nucleation and growth of voids. On the other hand, AF reinforced thermoplastic composites exhibit a microfailure based essentially on the matrix failure, and the composites become more damage tolerant with the increase in fiber aspect ratio. Stiffer AF leads to a more uniform interfacial shear stress distribution, with higher stiffness of the composite. Therefore, the effectiveness of AF to reinforce polymeric matrixes depends strongly on the elastic mismatch of the coupled materials. Local stress state in AF is correlated to macroscopic stress. AF may be recognized as a von Mises material. Ductile fracture in AF is controlled by nucleation and growth of voids. Increasing the fiber aspect ratio leads to more damage tolerant composites. Stiffer AF led to a more uniform interfacial shear stress distribution. [ABSTRACT FROM AUTHOR]

The demand for eco-friendly materials in automotive components has spurred research into natural fibers as sustainable alternatives for brake pads. This study examines the potential of date palm fibers, particularly the palm frond midrib (PFM), in brake pad composites. The effects of epoxy, PFM, and calcium carbonate on the composites' mechanical and tribological properties were analyzed. The optimal formulation (25% epoxy, 30% PFM, 35% calcium carbonate) exhibited superior properties, including a hardness of 87 HRB, wear rate of 1.5E-03 mg/mm, and COF of 0.73, surpassing commercial pads. Additionally, an inverse relationship between PFM/calcium carbonate content and compressibility was observed, with increased calcium carbonate enhancing wear resistance. This research underscores the potential of utilizing date palm resources in eco-friendly brake manufacturing, reducing the environmental and health impacts of traditional materials. [ABSTRACT FROM AUTHOR]

The mechanical qualities of natural fiber (NF) -based polymer composites are superior, making them advantageous and these composites are environmentally beneficial. The current investigation involved the fabrication of hybrid composites using Calotropis gigantea (CGF) and Abaca Fiber (AF) as reinforcements in epoxy matrix. The hand layup technique was employed for the fabricating process. Subsequently, the composites were investigated and analysed for their water absorption rate, tribological performance, and mechanical properties. This study aims to uncover a noteworthy combination of NF reinforced polymer composites that can be utilized in commercial Engineering applications. The mechanical properties were examined by measuring their hardness, impact resistance, flexural strength (FS), Compressive strength (CS), and tensile strength (TS). Furthermore, the broken surfaces of tensile sample were inspected utilizing a scanning electron microscope. Composite specimens were immensed in distilled water and their water penetration percentages were measured to ascertain their water absorption (WA) properties. The tribological performance was analysed utilizing a pin-on-disc equipment to assess the specific wear rate and coefficient of friction. The outcomes demonstrated that the hybrid composites surpassed the single-fiber composites in all variations. Sample G exhibited superior properties in all combinations, with a TS of 36.19 MPa and tensile modulus of 328.95 MPa. Additionally, it shows that higher flexural strength of 43.85 MPa and flexural modulus values of 350.84 MPa. Furthermore, it demonstrated higher Compressive strength of 94.45 MPa and modulus values of 576.93 MPa. Moreover, it exhibited a higher impact value of 53.88 kJ/m2 and higher hardness value of 44.07 HV. This material is well-suited for non-structural uses in electronics and electrical insulating boards and components, as the results show that a combination of CGF and AF fibers with an epoxy matrix improves mechanical qualities. [ABSTRACT FROM AUTHOR]

Coconut coir-based porous carbon (CCPC) and magnetic iron (Fe) particle composite (CCPC/Fe) have been developed and characterized for potential applications in unmanned aerial vehicles (UAVs). Coconut coir was extracted from coconut husks and Fe compounds are impregnated to form CCPC/Fe. A comprehensive analysis was conducted, encompassing XRD analysis, revealing the presence of crystalline Fe particles and amorphous carbon, with broadened peaks and a crystalline size of 16.68 nm. Raman spectroscopy showed distinctive structural properties. UV-Vis spectroscopy exposed unique absorption peaks and SEM imaging confirmed the retention of porous structures and the successful integration of Fe particles. EDS analysis provided insights into the elemental composition, emphasizing the varying compositions of the sample. The VNA testing reflection loss value of -26 dB (2 mm thick sample) calculated from VNA testing indicated EM wave attenuation of > 99 %. These results underscores the potential of CCPC/Fe, making it an attractive candidate for advanced applications like EM wave attenuation in UAVs. The research contributes to materials science by offering a sustainable, cost-effective solution to enhance electromagnetic compatibility in UAVs, ensuring dependable and secure operation across diverse environments. [ABSTRACT FROM AUTHOR]

The utilization of biofiber in recent years has significantly increased due to its advantages like being environmentally friendly, availability, and low costs. This paper investigates the physicochemical, mechanical, and morphological properties of the yucca fiber extracted by three methods such as water‐retting, traditional, and chemical methods. These analyses are designed to evaluate the extraction methodology and the hypothesis of the influence of harvesting location and growth conditions of the fiber. Various technologies are used, such as SEM, FTIR, XRD, and tensile tests. The fiber extracted by water retting is the strongest in the mechanical analysis with a strength of 690.48 MPa, followed by fiber extracted with the traditional method with 685.48 MPa, also 673.06, 657.94, 373.68 MPa for the fiber extracted by the chemical method using 3%, 5%, 10%NaOH respectively. The fiber obtained by the water retting method also has a higher chemical composition with 80.25% cellulose, 10.45% lignin, and 13.75% hemicellulose. The morphological characteristics are examined using Scanning Electron Microscopy. The crystallinity index ranged from 61.75% to 70.77%, and crystallite size from 1.73 to 2.04 nm is calculated from the XRD analysis. All these results confirm that yucca fiber can be a good sustainable choice for composite reinforcement. [ABSTRACT FROM AUTHOR]

Building envelopes with natural fibers are the future of sustainable construction, combining ecology and energy efficiency. The geopolymer building envelope was reinforced with innovative composite bars and two types of natural insulation (coconut mats and flax/hemp non-woven fabrics) were used as the core material. A 10 mol sodium hydroxide solution with an aqueous sodium silicate solution was used for the alkaline activation of the geopolymers. The purpose of this study was to confirm the feasibility of producing geopolymer composites with insulating layers made of renewable materials, which would have compressive strengths like those of C25/30-grade concrete and thermal conductivity coefficients like those of lightweight concrete. This publication presents the results of physicochemical tests on the base materials (oxide (XRF) and mineral phase (XRD) analysis as well as morphology and EDS) and studies the physical (density measurements), mechanical (flexural and compressive strength tests) and insulating properties (thermal conductivity measurements) of the finished sandwich partitions. The composites achieved a flexural strength of 7 MPa, a compressive strength of up to 30 MPa and a decrease in the thermal conductivity coefficient of about 60%. The research demonstrates contribution to sustainable construction by developing geopolymer composites, offering both structural integrity and superior thermal insulation. This innovation not only reduces reliance on traditional, carbon-intensive materials but also promotes the use of eco-friendly resources, significantly lowering the carbon footprint of construction. The integration of natural fibers into geopolymer matrices addresses key environmental concerns, advancing a rapidly growing field that aligns with global efforts toward energy efficiency, waste reduction, and circular economy principles in building design. [ABSTRACT FROM AUTHOR]

Expansive clays with high plasticity need to be stabilized to prevent hazards that may arise due to the extreme volume changes experienced with moisture fluctuations. Utilizing a kind of natural and eco-friendly sustainable fiber named as basalt fiber into the soils has become a new issue that needs to be expanded in scope. In this paper, a high plastic soil was stabilized by these natural basalt fibers to reduce possible soil-induced disasters. Basalt fibers in different lengths were mixed into the clay at varied amounts. Due to the soil's sensitivity to water, the samples were prepared at distinct water contents, 2 on the dry and 3 on the wet side of the optimum. To question whether the strength loss due to the moisture change can be regained with basalt fibers or not, the strength tests were performed on both natural and stabilized samples. Through the tests, it was revealed that the strength of the expansive clays can be enhanced up to 280% at a fiber content of 2%. The highest strength was obtained at approximately 880 kPa by mixing 24 mm fibers with 15% water at 1 and 2% ratios. As anticipated, the long fibers (24 mm) supplied a real reinforcement even at high water contents. In addition, the obtained data set was used to train machine learning algorithms (linear, ridge, lasso, support vector, decision tree) that have just started to be applied in geotechnical engineering. Results have proved that, the decision tree regression outperformed the stress and strain with 0.85 R-squared (R2) in stress and 0.91 R2 in strain estimation. Additionally, it was revealed from the feature importance analyses that water content has an importance of approximately 85% on stress and up to 97% on strain. [ABSTRACT FROM AUTHOR]

Highly efficient fiber-reinforced composites find extensive application in diverse industries. Yet, conventional fiber-reinforced composites have significant environmental impacts during both manufacturing and disposal. Environmentally friendly fiber-reinforced composites have garnered significant attention within the framework of sustainable development. Utilizing natural fibers in place of synthetic fibers and progressively decreasing the use of synthetic fibers are the main approaches to achieving a balance between economic progress and environmental quality. Attention is increasingly being drawn to natural fiber-reinforced biocomposites that exhibit outstanding environmental performance, exceptional physical and mechanical capabilities, and biological features. The lightweight and high-strength characteristics of these biocomposites enable them to significantly decrease the weight of structures, making them increasingly popular in many industries. The objective of this review is to evaluate the effectiveness of hybrid fiber-reinforced biocomposites in marine applications, specifically examining their mechanical characteristics, resistance to seawater, and ability to absorb moisture, all while advocating for sustainable material methodologies. To achieve this objective, the paper delineates the distinction between synthetic and natural fibers, examines the benefits of hybrid fiber-reinforced biocomposite materials, and addresses the obstacles and effective approaches in their production and application in seawater. Considering the review analysis, it can be inferred that the use of fiber-reinforced biocomposites in maritime applications shows significant potential and has abundant untapped growth prospects in the future years. [ABSTRACT FROM AUTHOR]

The need for natural fibers has increased in recent years due to more environmental consequences, which led to the exploration of novel biofibers. This research deals with extracting and characterizing fiber extracted from Cymbopogon nardus roots. The C. nardus root fibers were obtained from the roots of the C. nardus plant by manually retting. The C. nardus root fibers were analyzed for physio-chemical, morphological, thermal, crystalline, and mechanical properties. The test results elucidated that the cellulose contents of C. nardus root fibers were 65.67%, and the density was 1192 kg/m3, which was less than synthetic ones to prove its lightweight behavior. The crystallinity index of C. nardus Root fibers was 59.16%, demonstrating the extracted fiber's higher-order crystal nature. Fourier Transform Infrared Spectroscopy proved the various crystalline and amorphous contents in the C. nardus root fibers. Scanning Electron Microscope elucidated the multiple features of the C. nardus root fibers, demonstrating its suitability as reinforcement for the composite to suit versatile, lightweight, medium-load applications. [ABSTRACT FROM AUTHOR]

Textile waste is becoming among the most polluting waste in the world, discarded mostly in landfills. Valorizing textile waste via anaerobic digestion (AD) helps conserve resources, reduce environmental impact, and foster a circular economy. Although several reviews have discussed textile waste AD, there is a lack of detailed understanding of the challenges encountered during textile waste AD. Therefore, the goal of this review is to focus on challenges encountered and possible solutions for those challenges for biogas and fertilizer conversion via AD. Potential strategies include chemical, biological, and thermal pretreatments that significantly increase the digestion process. Co‐digestion of natural textile waste, cotton, and wool with carbon and nitrogen‐rich substrates improves AD efficiency by twofold. Moreover, separating polyester from polycotton and textile dye removal via solvent and advanced oxidation processes significantly increases methane yield compared with untreated textile waste. This review can aid in analyzing suitable methods to optimize the biogas production of textile waste via AD. [ABSTRACT FROM AUTHOR]

This study investigates the mechanical properties of carbon and natural fiber-reinforced Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol (PETG) composites produced via Additive Manufacturing (AM), focusing on Material Extrusion (MEX). The performance of filaments made from pre-consumer recycled PLA (rPLA) and PETG, with varying weight percentages of hemp and jute short fibers, was evaluated through tensile testing. Comparisons were made between the original filaments (PLA, carbon fiber-reinforced PLA [CF–PLA], and PETG) and their recycled versions. Multi-material compositions—neat PLA and PETG, single-graded (PLA + CF–PLA, PETG + CF–PETG), and multi-gradient (PLA + CF–PLA + PLA, PETG + CF–PETG + PETG)—were analyzed for mechanical properties. Optical microscope images of multi-material specimens were captured before and after fracture to assess failure mechanisms. The results indicate that the original CF–PETG filaments achieved a tensile strength of 50.14 MPa, which is higher than rPLA, PLA, and CF–PLA by 2%, 70%, and 6.7%, respectively. The re-manufactured PLA filaments reinforced with 7 wt% hemp fibers exhibited a tensile strength of 38.8 MPa, representing a 29% increase compared to the original PLA filaments and a 26% improvement over recycled PLA. Additionally, incorporating 7% jute fiber into PETG resulted in a tensile strength of 62.38 MPa, reflecting a 12% improvement over the original PETG filaments and a 15% increase compared to the recycled PETG filaments. Among specimens produced by AM, CF–PLA and rPLA demonstrated the highest tensile and compressive strengths. However, multi-material composites showed reduced mechanical performance compared to neat PLA and PETG, highlighting the need for improved interlayer adhesion. This study emphasizes the importance of optimizing material combinations and fiber reinforcement to enhance the mechanical properties of composites produced through AM. [ABSTRACT FROM AUTHOR]

The renewable nature and exceptional strength-to-weight ratio of bamboo have led to numerous studies on incorporating bamboo fiber (BF) in composite fabrication. The mechanochemical BF extraction process used to produce high-quality micron fibers still faces limitations such as low percentage (%) yield and hydrophilicity. Moreover, the bead formation during BF extraction reduces the % yield and complicates the fiber separation process. This study introduces an innovative method for extracting BF with fewer fiber beads to improve the % yield. The process parameters were optimised using the response surface method (RSM) having a face-centred central composite design (FCCD). The optimal fiber extraction conditions were 80.61 min of boiling with 15% NaOH concentration and stirring at 1800 rpm. The most influencing parameter was identified using analysis of variance (ANOVA) and parametric analysis. Diisopropanolamine (DIPA) was used to graft amine functional groups on BF's surface to increase their hydrophobicity, whose confirmation was obtained using water retention value (WRV) analysis. Fourier-transform infrared spectroscopy (FTIR) validates the surface modification of BF. The crystallinity of BF appeared to be minimally affected by the DIPA modification, as confirmed by the X-ray diffraction (XRD) analysis. Field-emission scanning electron microscopy (FESEM) analysis of BF and DIPA-modified BF reveals well-separated fibers with minimal cellulose surface peeling after surface treatment. Thermogravimetric (TG) and differential thermogravimetric (DTG) analyses were also accomplished to validate the improved thermal stability of BF by amine-based treatment. [ABSTRACT FROM AUTHOR]

Presently, novel materials based on natural fibers are emerging daily to replace synthetic fibers in various engineering disciplines, as they minimize environmental pollution, allow for easy processing, provide superior strength, and promote industrial sustainability. The global demand for novel eco-friendly fibers for composites has paved the way for this work. This work uses epoxy as a matrix material, and polymer composites with reinforcement from untreated and alkali-treated Zanthoxylum acanthopodium bark fibers (5–25 wt.%). Hand lay-up was used in the development of the epoxy composites. The mechanical characteristics and water absorption rates of the produced epoxy composites were evaluated following ASTM standards. Epoxy composites containing 20 wt.% of alkali-treated Zanthoxylum acanthopodium bark fibers had excellent mechanical qualities, including an ultimate tensile strength of 47.3 MPa, according to the test findings. However, there was a positive correlation between fiber loading and water absorption. The fiber bonding and void properties of the investigated composites were viewed with a scanning electron microscope. [ABSTRACT FROM AUTHOR]

This study shows the influence of the inclusion of abaca fiber (Musa Textilis) on the coefficients of consolidation, expansion, and compression for normally consolidated clayey silt organic soil specimens using reconstituted samples. For this purpose, abaca fiber was added according to the dry mass of the soil, in lengths (5, 10, and 15 mm) and concentrations (0.5, 1.0, and 1.5%) subjected to a curing process with sodium hydroxide (NaOH). The virgin and fiber-added soil samples were reconstituted as slurry, and one-dimensional consolidation tests were performed in accordance with ASTM D2435. The results showed a reduction in void ratio (compared to the soil without fiber) and an increase in the coefficient of consolidation (Cv) as a function of fiber concentration and length, with values corresponding to 1.5% and 15 mm increasing from 75.16 to 144.51 cm2/s. Although no significant values were obtained for the compression and expansion coefficients, it was assumed that the soil maintained its compressibility. The statistical analysis employed hierarchical linear models to assess the significance of the effects of incorporating fibers of varying lengths and percentages on the coefficients, comparing them with the control samples. Concurrently, mixed linear models were utilized to evaluate the influence of the methods for obtaining the Cv, revealing that Taylor's method yielded more conservative values, whereas the Casagrande method produced higher values. [ABSTRACT FROM AUTHOR]

The increasing demand for high-performance materials has led to the development of natural fiber composites as an alternative to synthetic fiber composites. However, the low thermal conductivity of natural fibers limits their use in advanced applications. In this study, we have developed polyaniline-coated natural fiber composites to enhance their thermal properties. The methodology of this study involves the preparation of natural fiber composites using polyaniline-coated natural fibers as a reinforcement and a bio-based resin as a matrix. The composites were then coated with polyaniline, which was synthesized through chemical oxidation of aniline monomer. The coated composites were characterized using various analytical techniques such as Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis to evaluate their structural, morphological, and thermal properties. The materials used in this study were natural fibers, bio-based resin, aniline monomer, ammonium persulfate, and hydrochloric acid. The gap identification of this study is the low thermal conductivity of natural fiber composites, which limits their application in advanced fields such as aerospace, automotive, and electronics. The problem identification is the lack of a cost-effective and eco-friendly method to enhance the thermal properties of natural fiber composites. The results of this study showed that the polyaniline-coated natural fiber composites exhibited enhanced thermal conductivity compared to the uncoated composites. The improvement in the properties of the composites was attributed to the high conductivity of polyaniline and its ability to form a continuous conductive network throughout the composite matrix. The development of polyaniline-coated natural fiber composites provides a cost-effective and eco-friendly approach to enhance the thermal properties of natural fiber composites. This approach has the potential to expand the use of natural fiber composites in advanced applications, leading to a sustainable and greener future. [ABSTRACT FROM AUTHOR]

This community service activity aims to enhance the skills of the Karang Taruna in Dusun Mriyan Utara, Bantul Regency, in making eco-friendly light bricks from rice husk as earthquake-resistant lightweight bricks. The method used in this community service involves participatory training, where youth groups actively make light bricks from natural waste. The evaluation instruments for this activity include direct observation and post-tests, which are analyzed descriptively to measure the participants' improvement in skills and knowledge. The results of this community service indicate that the people of Dusun Mriyan Utara are very enthusiastic and have successfully improved their skills in making light bricks, which can be developed as a flagship product of the village and a preventive measure in earthquake disaster mitigation.

This study investigates the incorporation of boron carbide (B4C) filler particulates into a kenaf fiber-reinforced epoxy matrix to explore its potential in lightweight applications, focusing on antimicrobial effectiveness, mechanical integrity, thermal properties, and microstructural characteristics. The composite material was formulated by blending varying seven different concentrations of boron carbide (0–50 g) and kenaf fibers (KFs) with an epoxy resin, aiming to achieve a balance between mechanical strength and minimal weight. Antimicrobial test revealed that the composite material, consisting of kenaf fiber reinforced with B4C particulates, exhibited significant antibacterial activity against common pathogens. Mechanical testing indicated that the addition of boron carbide and kenaf fibers significantly improved the tensile strength and flexural rigidity of the composites. Specifically, enhancements in tensile strength and flexural modulus were quantitatively analyzed, showing notable increases compared to the base epoxy resin. Scanning Electron Microscopy (SEM) was employed to examine the fracture surfaces following mechanical testing, revealing improved interfacial bonding between the kenaf fibers and the epoxy matrix due to the presence of boron carbide. This microscopic analysis also highlighted areas where stress distribution was optimized, contributing to the composite's enhanced mechanical properties.

Abstract The demand for eco-friendly materials in automotive components has spurred research into natural fibers as sustainable alternatives for brake pads. This study examines the potential of date palm fibers, particularly the palm frond midrib (PFM), in brake pad composites. The effects of epoxy, PFM, and calcium carbonate on the composites’ mechanical and tribological properties were analyzed. The optimal formulation (25% epoxy, 30% PFM, 35% calcium carbonate) exhibited superior properties, including a hardness of 87 HRB, wear rate of 1.5E-03 mg/mm, and COF of 0.73, surpassing commercial pads. Additionally, an inverse relationship between PFM/calcium carbonate content and compressibility was observed, with increased calcium carbonate enhancing wear resistance. This research underscores the potential of utilizing date palm resources in eco-friendly brake manufacturing, reducing the environmental and health impacts of traditional materials.

This study aims to develop, enhance, and characterize the qualities of recycled jute fiber and kraft pulp as reinforcement for use in cement composite boards for building applications in developing countries. In many African countries, jute fiber (Corchorus capsularis) is readily available but faces challenges in achieving a strong bond with the cement matrix. To address this, mild treatment with different alkali concentrations was employed to modify the fiber properties before reinforcement. Alkali treatment significantly improved fiber characteristics such as tensile strength, Young's modulus, thermal stability, and surface morphology, as confirmed by the single fiber tensile test, thermogravimetric analysis, and scanning electron microscopy, respectively. Using a laboratory-simulated Hatschek process, cement composite boards were produced with varying percentages (2–6 wt.%) of treated and untreated jute fiber. The mechanical properties and fractured surface morphology of the boards were examined through a three-point bending test and scanning electron microscopy. Results showed that the composites reinforced with treated fibers exhibited significantly improved flexural strength and ductility compared with the untreated ones. SEM examination revealed that the untreated fiber-reinforced composite experienced fiber pull-out due to poor bonding at the fiber–matrix interface. In contrast, the composites reinforced with treated fibers displayed optimal strength, meeting the minimum requirements for fiber cement flat sheets according to relevant standards. An optimum flexural strength of 9.57 MPa was achieved for composite boards containing 10 and 4 wt.% of kraft pulp and treated jute fibers, respectively. Overall, this study demonstrates that recycled jute fibers could be successfully enhanced and reused as reinforcement in cement composite boards, leading to improved properties and mechanical performance in cement composite boards. Hence, it provides environmental benefits and contributes to the circular economy. [ABSTRACT FROM AUTHOR]

Environmental challenges associated with synthetic reinforcement in polymer composites, such as non-biodegradability and poor recyclability, require the exploration of various natural materials, especially from waste streams, to fully or partially replace such reinforcements. However, these natural fibers also present challenges such as high water absorption, low thermal stability, and average mechanical properties. To circumvent these problems, natural fiber-reinforced hybrid composites, which contain one or more types of natural reinforcement, are gaining increasing research interest. This paper presents a review of natural fiber-reinforced hybrid composites. Both thermoplastics and thermosets reinforced by natural and synthetic fibers (hybrid fibers) are reviewed. The properties of fibers and the resulting composites and processing techniques are summarized.

This article is a literature review of several studies oriented toward the treatment of natural fiber to improve the surface morphology and tensile strength of the fiber. The method used is to review several studies that describe the physical and mechanical properties of natural fiber with different treatments such as immersion of sago fiber in liquid smoke, coconut fiber in NaOH, palm fiber in seawater, and smoking of king pineapple fiber, and banana stem fiber with liquid smoke. The results of the review showed that the treatment was able to increase the tensile strength of sago fiber by 26.77%, coconut fiber by 81.25%, palm fiber by 67.40%, waru bark fiber by 59,97%, coconut fiber with limestone water 34,96 %, king pineapple fiber by 74.45%, and banana stem fiber by 43.78%. The effect of some of these treatments can also change the morphology of the fiber. So, it was concluded that treatment was needed to change the physical properties of the fiber in the form of morphology and mechanical properties in the form of better fiber tensile strength so that the fiber used as a composite reinforcement could improve the mechanical properties of the composite.

Retting has been employed to extract natural fibers from agricultural wastes as a biological and cost-effective approach for centuries. With its global abundance, banana pseudo-stem is a promising agro-waste for lignocellulosic fiber extraction. In this study, fibers were extracted from the pseudo-stems after being pre-treated under four conditions using seawater at room temperature for up to 35 d Bacterial isolation from the fresh seawater sample and screening for ligninolytic ability were conducted. Bacterial load as well as laccase and manganese peroxidase enzyme activity profile assay during the retting duration were analyzed. Fourier transform infrared (FT-IR) and X-day diffraction (XRD) analyses were also examined for both pre-treated and untreated extracted fibers. The results shows that six out of the eight bacterial isolates had the ability to degrade lignin. The treatments (Raw stem + Raw seawater) and (Autoclaved stem + Raw seawater) recorded the highest viable bacterial load of 9.24 × 102 and 4.46 × 102 CFU, respectively, on the 14th day of the retting process. Additionally, the highest laccase and manganese peroxidase enzymes activity was recorded for (Raw stem + Raw seawater) and (Autoclaved stem + Raw seawater) treatments in the second to the third week. The FT-IR spectra of the pre-treated fibers revealed relative reductions in peaks attributed to polysaccharides and other amorphous substances for all retting conditions. The XRD diffractogram revealed that the crystallinity index (CI) of pre-treated fibers increased in all seawater retting treatment conditions. However, the CI for fibers pre-treated under enzymatic conditions were enhanced even after five weeks. Sequence analysis for selected bacterial isolates showed homology to sequences of Bacillus velezensis, Shewanella sp. L8–5, and Citrobacter amalonaticus and Bacillus subtilis j8 strain. From these findings, it was suggested that physical, biological, and chemical actions were collectively involved in the seawater retting process of banana pseudo-stems.

Natural fibre-reinforced polymer composite (NFRPC) has been introduced as one of the solutions to overcome the ecological and environmental problems accompanying the widespread usage of polymeric materials in every facet of life. However, the organic nature of both natural fibres (NFs) and polymers increases their flammability behaviour, and this, in turn, limits their application. In this regard, this work concentrates on studying the effect of adding flame retardants (FR) to jute-reinforced epoxy composites (JRECs), either by treating the jute fabric with diammonium phosphate (DAP) or adding DAP powder to the epoxy resin matrix on the flame retardancy performance as well as the mechanical properties. The results showed that the effect of the incorporation method of DAP either to jute fabric or to resin matrix has a significant difference on the flammability test results at low concentrations; however, at higher concentrations, the flame retardancy performance is not affected by the technique of adding FR to the composite system. On the other hand, the mechanical properties are significantly affected by the method of incorporating FR to JRECs at all concentrations. Moreover, the results obtained from JRECs with FR systems were evaluated and compared with the literature by constructing selection charts that relate the flame retardancy level to mechanical properties.

This research explores the extraction and application of cellulose fibers from various parts of plants, specifically young and old stems, as well as seed/fruit skins. The primary focus was on the effective removal of lignin and other extraneous compounds to enhance the properties of cellulose fibers for their subsequent use as fillers in the production of porous composites. These composites were evaluated for their responsiveness to ammonia vapor through a color change test, indicating their potential as intelligent, environmentally friendly packaging materials. The cellulose fibers were isolated through a two-stage process involving delignification using 20 % sodium hydroxide (NaOH) and bleaching with a 5 % hydrogen peroxide (H2O2) and 3.8 % NaOH mixture. These fibers were then characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffractometry (XRD), and Scanning Electron Microscopy (SEM). The analysis revealed that fibers extracted from the younger stem bark exhibited superior characteristics, notably in their crystallinity index (CI), which was 5.16 % higher than that of fibers from other plant parts. Surface morphological studies indicated that the cellulose fibers derived from CG plants possess a hollow shape. When used as fillers, these fibers contributed to the enhanced porosity of polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) composites. SEM analysis further demonstrated that the inclusion of fibers with higher degrees of crystallinity significantly increased the composites' porosity. Additionally, composites immobilized with anthocyanins from the Butterfly Pea Flower (BPF) exhibited a notable colorimetric response to environmental pH changes. Thermogravimetric analysis suggested that incorporating these fibers into the composite matrix improves thermal stability. The study's findings underscore the potential of these porous composites as colorimetric indicators, paving the way for their application in smart, eco-friendly packaging solutions.

Seaweed from macroalgae and cellulose from nonwood materials have gained attention in various fields. This study explores how seaweed and cellulose nanofibers (CNF) interact to form 3D networks in composite bioaerogels. The ratio of CNF and seaweed was varied to see how it affects the aerogel’s inside and its properties. The observations show that the biocomposite aerogel is more rigid and shrinks less than using a single biopolymer. The CNF aerogel has a fine, thin network structure, and the seaweed aerogel has a thin sheet structure. The biocomposite aerogel combines both a fine network and a thin sheet structure. The composite aerogel’s mechanical properties are significantly influenced by seaweed composition. The introduction of CNF increases elasticity, while seaweed enhances firmness. Generated computer modelling revealed that the abundant hydroxyl groups in CNF facilitated the formation of intermolecular bonds with seaweed. The bonding led to increased adhesion and entanglement between biopolymers, consequently enhancing elasticity and establishing a stable intermolecular interaction. The 3D X-ray imaging model shows that the skeletal framework primarily consists of seaweed biopolymer, with CNF serving to reinforce this structure thus enhancing the mechanical properties and robustness of the composite bioaerogels.

This research explores natural fiber composites (NFCs) as alternatives to traditional materials such as fiberglass. By examining fibers like abaca, bamboo, banana, coir, flax, hemp, jute, kenaf, pineapple leaf (PALF), sisal, and others, we emphasize their lower weight, cost-effectiveness, competitive mechanical properties, commendable specific strength, and potential for biodegradability. NFCs offer practical and eco-friendly substitutes for conventional composite fibers in industries like construction, automotive, and packaging. The article provides a brief overview of NFCs, covering their chemical, physical, and mechanical characteristics, and highlights diverse applications. The comparative analysis underscores the potential of natural fibers as sustainable choices in various industries.

In recent decades, in order to replace traditional synthetic polymer composites, engineering research has focused on the development of new alternatives such as green biocomposites constituted by an eco-sustainable matrix reinforced by natural fibers. Such innovative biocomposites are divided into two different typologies: random short fiber biocomposites characterized by low mechanical strength, used for non-structural applications such as covering panels, etc., and high-performance biocomposites reinforced by long fibers that can be used for semi-structural and structural applications by replacing traditional materials such as metal (carbon steel and aluminum) or synthetic composites such as fiberglass. The present research work focuses on the high-performance biocomposites reinforced by optimized sisal fibers. In detail, in order to contribute to the extension of their application under fatigue loading, a systematic experimental fatigue test campaign has been accomplished by considering four different lay-up configurations (unidirectional, cross-ply, angle-ply and quasi-isotropic) with volume fraction Vf = 70%. The results analysis found that such laminates exhibit good fatigue performance, with fatigue ratios close to 0.5 for unidirectional and angle-ply (±7.5°) laminates. However, by passing from isotropic to unidirectional lay-up, the fatigue strength increases significantly by about four times; higher increases are revealed in terms of fatigue life. In terms of damage, it has been observed that, thanks to the high quality of the proposed laminates, in any case, the fatigue failure involves the fiber failure, although secondary debonding and delamination can occur, especially in orthotropic and cross-ply lay-up. The comparison with classical synthetic composites and other similar biocomposite has shown that in terms of fatigue ratio, the examined biocomposites exhibit performance comparable with the biocomposites reinforced by the more expensive flax and with common fiberglass. Finally, appropriate models, that can be advantageously used at the design stage, have also been proposed to predict the fatigue behavior of the laminates analyzed. [ABSTRACT FROM AUTHOR]

Geopolymers are synthesized using anthropogenic raw materials and waste from the energy industry. Their preparation necessitates an alkaline activator, which facilitates the dissolution of raw materials and their subsequent binding. At present, geopolymers are considered a promising material with the potential to replace conventional cement-based products. This research investigates foamed geopolymer materials based on fly ash, natural fibers, and phase-change materials. The study utilized three distinct types of fibers and two phase-change materials manufactured by Rubitherm Technologies GmbH of Germany. This paper presents the results of the thermal conductivity coefficient and specific heat tests on the finished foams. Additionally, compressive strength tests were conducted on the samples after 28 days. Natural fibers decreased the insulation parameter by 12%, while PCM enhanced it by up to 6%. The addition of fibers increased the compressive strength by nearly 30%, whereas PCM reduced this by as little as 14%. Natural fibers and phase-change materials had an increased heat capacity by up to 35%. The results demonstrated the material's potential in various industrial sectors, with the primary areas of application being building materials and insulations. The findings illustrate the significant potential of these composites as energetically and environmentally sustainable materials. [ABSTRACT FROM AUTHOR]