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Basaltic pumice has a black or gray appearance due to its iron and magnesium-rich komatiitic tuff composition. Pumice's porous structure allows the production of various polymer-based biocomposite materials for biomedical applications. This study developed bio-composite samples by incorporating basaltic pumice powder at 2.5, 5.0, 7.5, and 10.0 percent concentrations into an elastomeric polyurethane (EPU) matrix. The surface and elemental structure of basaltic pumice particles were investigated using the SEM/energy diffraction X-ray technique. The physical, mechanical, thermal, melt-flow, and morphological properties of bio-composites were studied experimentally. Findings showed a rise in Shore hardness and tensile modulus parameters and declined tensile elongation. According to the thermal study, introducing basaltic pumice resulted in a modest drop in the thermal stability of the EPU and an improvement in stability against mechanical deformations. Pumice loadings raised the melt flow and extrusion torque values of the EPU. The observation of the homogeneously distributed pumice particles in the EPU matrix is used as visual evidence to investigate the highest performance among the composites in the EPU sample with the lowest loading rate of 7.5% pumice. Overall, BP is effective as a reinforcing agent in EPU-based biocomposites at low additive percentages. [ABSTRACT FROM AUTHOR]

The current study aims to develop a cutting-edge methodology to enhance compatibility between natural fiber and polymeric matrix in bio-composites. To achieve this, an innovative approach for grafting an azide functional group (Az) onto the surface of polypropylene (PP) was successfully developed and confirmed. The Az group contributed to enhancing the interfacial interaction between the polymer matrix and the bio-filler through chemical crosslinking. Crosslinking is achieved through an innovative and efficient chemical process known as click chemistry. In particular, a click reaction is established between the functionalized PP with an azide group and functionalized natural filler with an alkyne group. The effectiveness of the proposed technique is verified using Fourier Transform Infrared (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Thermo-Gravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM). The resulting bio-composite exhibits higher mechanical properties, better thermal stability, and improved biocompatibility compared to conventional materials. Specifically, the maximum tensile strength was achieved at 10% DPP loading, showing a 22% increase over the base material (DPP/PP) and a 7% increase over neat PP. A more significant enhancement was observed in Young's modulus results across all samples. Therefore, the established method is beneficial for polymer modification, promoting the production of high-performance bio-composite materials. [ABSTRACT FROM AUTHOR]

We aimed to obtain the mechanical properties of the resulting bio-composite material. Mechanical properties of bio-composite materials are greatly influenced by the fiber content and molding process parameters used. We used kenaf fiber as reinforcement and epoxy resin as a binder. Molding parameters such as molding time, molding pressure, and molding temperature were implemented to get the best bio-composite material. We used two types of kenaf fibers at content of 20 wt.%, which consisted of long fiber (first filler) and short fiber (second filler) as reinforcement, at compositions of 10:10, 12.5:7.5, 15:5, and 17.5:2.5 based on weight percentage (wt.%), respectively. Our results showed that the fiber content and molding process parameters used had a significant effect on the resulting mechanical properties. The highest flexural strength value was obtained at a fiber content of 5 wt.%, amounting to 44.77 MPa. By applying the molding process parameters, the flexural strength value obtained was successfully increased up to 58 MPa at a molding pressure of 270 kg/cm2. The scanning electron microscope (SEM) results showed that the fiber content of 5 wt.% could be distributed well throughout the matrix, as well as increasing the molding pressure successfully reducing the voids formed during the molding process of the resulting bio-composite material. [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]

Natural fibre-based polymer composites have better improvements owing to their thermal and mechanical properties besides environmentally friendly quality. In the present work, biocomposite fabricated at kenaf fibres (KF) loading (30, 40, 50, and 60 mass%) with bio epoxy matrix by the hot compression moulding method, and their thermal and dynamic mechanical characterisation were investigated and examined. This study was conducted to investigate the thermal behaviour through thermogravimetric analysis (TGA) and the derivative of thermogravimetric analysis (DTG: the maximum thermal decomposition; Tmax), dynamic mechanical analysis (DMA) and thermomechanical analysis (TMA). The presented findings from TGA and DTG curves showed that the thermal stability improved with increasing the KF loadings, as evidenced by the higher residual mass % and the lower mass loss %. On the other hand, it was found that the biocomposite sample (50 mass% KF) exhibited higher thermal stability up to 558.82 °C. Furthermore, the DMA findings obtained exhibited the greatest value of the storage modulus (E') with the following order of KF bio composite (KF-50 > KF-60 > KF-40 > KF-30). On the other hand, the values of loss modulus (E'') were increased as follows KF-30 > KF-40 > KF-50 > KF-60. However, the results showed that 50 mass% of KF into epoxy biocomposites recorded higher loss modulus value (323.56 MPa) among all other bio composite samples, while the values of tan δ were increased as follows: KF-30 > KF-40 > KF-50 > KF-60. The results obtained for the TMA revealed a better coefficient of thermal expansion (CTE) for the sample (KF-50) compared to other samples. [ABSTRACT FROM AUTHOR]

The interest in natural fibres and biopolymers for developing bio-composites has greatly increased in recent years, motivated by the need to reduce the environmental impact of traditional synthetic, fossil fuel-derived materials. However, several limitations associated with the use of natural fibres and polymers should be addressed if they are to be seriously considered mainstream fibre reinforcements. These include poor compatibility of natural fibres with polymer matrices, variability, high moisture absorption, and flammability. Various surface treatments have been studied to tackle these drawbacks, such as alkalisation, silane treatment, acetylation, plasma treatment, and polydopamine coating. This review paper considers the classification, properties, and limitations of natural fibres and biopolymers in the context of bio-composite materials. An overview of recent advancements and enhancement strategies to overcome such limitations will also be discussed, with a focus on mechanical performance, moisture absorption behaviour, and flammability of composites. The limitations of natural fibres, biopolymers, and their bio-composites should be carefully addressed to enable the widespread use of bio-composites in various applications, including electronics, automotive, and construction. [ABSTRACT FROM AUTHOR]

The study involves extracting and characterizing fibers from the Typha Domingensis Pers (TDP) plant for the development of bio-composite sheets. The mechanical extraction process yielded 9.3% fibers with a high cellulose content of 70.45 wt%. These fibers also had a thermal stability of 210 °C, making them suitable for withstanding high temperatures during the composite preparation process. Using the hand layup process, three variations of bio-composite sheets were made by mixing sodium alginate and paddy husk powder in different ratios. The sheets were then tested for the basic mechanical, absorbency, and biodegradability properties. The bio-composite sheet blend 2 (BC2), which contained 50% fibers and 50% matrix, showed the greatest tensile and flexural strengths of 242 and 292 MPa, respectively, with lower moisture absorption properties. All three bio-composite sheets exhibited 100% biodegradability. However, bio-composite 1 (BC1) showed significant biodegradability within 60 days. The study revealed that fibers from the invasive Typha domingensis Pers plant can be utilized to create biodegradable composites with desirable properties, making them suitable for use as green planters and other similar agricultural applications. [ABSTRACT FROM AUTHOR]

Biodegradable poly(butylene succinate‐co‐adipate)/Poly(3‐hydroxybutyrate‐co‐3‐hydoxyvalerate) (PBSA/PHBV) filled with lignocellulosic sidestream/fibers from cowpea, a neglected and underutilized African crop are produced by injection molding and extrusion film casting. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) suggests that the fibers have more affinity and interfacial interaction with PBSA than PHBV. This is shown by a decrease in dampening of PBSA and an increase in dampening of PHBV with fiber addition. In addition, fiber addition results in more homogeneous crystal morphology of PBSA, while resulting in more heterogeneous crystal morphology of PHBV. The tensile strength of injection molded bio‐composites increases with fiber addition due to good interfacial adhesion between the matrix and fibers revealed by scanning electron microscope. In contrast, the tensile strength of bio‐composite films decreases with fiber addition due to the high‐volume fraction of pores in bio‐composite films that act as stress raisers. The stiffness of both injection molded, and bio‐composite films increase with fiber addition, as revealed by an increase in Young's modulus and storage modulus, while the tensile strain decreases. In conclusion, low‐value cowpea sidestream can be used as a filler to produce injection molded bio‐composites and bio‐composite films for potential application as rigid and flexible packaging. [ABSTRACT FROM AUTHOR]

Corn straw-based board has great potential for the protection of forest resources, waste recycling, and sustainable economic development. However, corn stalk-based board has poor mechanical properties due to its short fiber length and poor water resistance because of the presence of numerous hydrophilic hydroxyl functional groups in its structure. Natural mycelium originating from waste Pleurotus ostreatus substrate is a hydrophobic bio-adhesive. In the present study, formaldehyde-free corn stalk/P. ostreatus substrate bio-composites were prepared using the hotpressing technique without the addition of any chemical adhesive. The mechanical properties and water resistance of the prepared biocomposites were excellent. The highest internal bonding strength (IBS) of 2.16 MPa and the minimum thickness swelling (TS) of 18.3% were observed, which are beyond the national standards for particleboard in China. These bio-composites were prepared using a simple, green, and convenient manufacturing method to promote their popularization and application. The method may, therefore, be used as a novel technical measure to resolve the problem of overuse of forestry resources and waste disposal. [ABSTRACT FROM AUTHOR]

Grape seeds (GS), wine lees (WL), and grape pomace (GP) are common winery by-products, used as bio-fillers in this research with two distinct biopolymer matrices—poly(butylene adipate-co-terephthalate) (PBAT) and polybutylene succinate (PBS)—to create fully bio-based composite materials. Each composite included at least 30 v% bio-filler, with a sample reaching 40 v%, as we sought to determine a composition that could be economically and environmentally effective as a substitute for a pure biopolymer matrix. The compounding process employed a twin-screw extruder followed by an injection molding procedure to fabricate the specimens. An acetylation treatment assessed the specimen's efficacy in enhancing matrix–bio-filler affinity, particularly for WL and GS. The fabricated bio-composites underwent an accurate characterization, revealing no alteration in thermal properties after compounding with bio-fillers. Moreover, hygroscopic measurements indicated increased water-affinity in bio-composites compared to neat biopolymer, most significantly with GP, which exhibited a 7-fold increase. Both tensile and dynamic mechanical tests demonstrated that bio-fillers not only preserved, but significantly enhanced, the stiffness of the neat biopolymer across all samples. In this regard, the most promising results were achieved with the PBAT and acetylated GS sample, showing a 162% relative increase in Young's modulus, and the PBS and WL sample, which exhibited the highest absolute values of Young's modulus and storage modulus, even at high temperatures. These findings underscore the scientific importance of exploring the interaction between bio-fillers derived from winery by-products and three different biopolymer matrices, showcasing their potential for sustainable material development, and advancing polymer science and bio-sourced material processing. From a practical standpoint, the study highlighted the tangible benefits of using by-product bio-fillers, including cost savings, waste reduction, and environmental advantages, thus paving the way for greener and more economically viable material production practices. [ABSTRACT FROM AUTHOR]

Nanocomposites of sodium alginate (SA) and TiO2 nanoparticles have gained attention in the last decade for their versatile uses in several applications. Indeed, TiO2 is particularly appealing for its photocatalytic and antimicrobial activity and inherent safety. In this paper, TiO2 nanoparticles are successfully embedded, synthesized by a microwave‐assisted method, into SA matrix by a simple solvent casting method to form flexible and self‐consistent SA/TiO2 films. FT‐IR, XRD, and contact angle measurements confirm the formation of homogeneous and hydrophilic bio‐composites films that may be suitable for packaging or life science applications. [ABSTRACT FROM AUTHOR]

In this study, the frequency and deflection response analysis of basalt, soy, flax and hybrid pineapple and flax hybrid laminated skew plates are done. The conventional hand-layup method is used to fabricate the different bio-composites-based laminated structures. The uniaxial tension test is conducted in the INSTRON 5967 UTM to determine the elastic properties of the bio-composite laminated structure as per ISO 527-5 standards. The hybrid laminate skew plate is modeled using the first-order shear deformation theory (FSDT) and their elastic properties are obtained from the uniaxial tensile test from which the frequency and deflection of the skew laminated plates are calculated. The eight-noded shell elements (S8R5) with each node having five degrees-of-freedom are deputed in the commercial finite element method (FEM) package ABAQUS to beget the numerical solutions. The damping effect is neglected in the analysis. The accuracy of the proposed model is verified with available literature and found to be in good agreement. Later, the effect of different parameters such as boundary conditions, aspect ratio and skew angles on the natural frequency and deflection of the bio-composites hybrid laminated skew plates are investigated. The obtained results inferred the natural frequencies are decreasing with an increasing aspect ratio of skew plates. The skew angles help to increase the natural frequencies of skew plates. The central deflections are lower for high-skew angled laminated plates. [ABSTRACT FROM AUTHOR]

To meet societal and economic expectations, the bio-based composite market is developing. However, some issues remain, especially for lignocellulosic fiber composites, due to their highly hydrophilic nature which impacts the composite performance. This study focuses on bamboo fiber-polypropylene composites manufactured by film stacking using fiber mats obtained through a wet laid process. To individualize fibers, raw bamboo was cooked using an alkaline treatment: the soda process, i.e., using NaOH in order to keep a certain amount of lignin on fiber surface. A maximum surface lignin content of 81.%, measured by XPS analysis, was obtained, from the 1 wt.% NaOH concentration. The corresponding bulk lignin content, measured by Klayson method, is 21.%. The macroscopic properties of bamboo fiber-polypropylene composites were evaluated with regard to material microstructure through a multiscale analysis. The best mechanical properties were obtained for composites manufactured from bamboo fiber prepared using a 1 wt.% NaOH, which corresponds to the highest lignin content (3.5 GPa and 53 MPa for modulus and strength in tensile tests, 3.8 GPa and 64 MPa in bending tests). The good mechanical performance of the composites was attributed to the improved compatibility between the fiber and the matrix, evidenced by multiscale studies. [ABSTRACT FROM AUTHOR]

The demand for high-performance bio-based materials towards achieving more sustainable manufacturing and circular economy models is growing significantly. Kraft lignin (KL) is an abundant and highly functional aromatic/phenolic biopolymer, being the main side product of the pulp and paper industry, as well as of the more recent 2nd generation biorefineries. In this study, KL was incorporated into a glassy epoxy system based on the diglycidyl ether of bisphenol A (DGEBA) and an amine curing agent (Jeffamine D-230), being utilized as partial replacement of the curing agent and the DGEBA prepolymer or as a reactive additive. A D-230 replacement by pristine (unmodified) KL of up to 14 wt.% was achieved while KL–epoxy composites with up to 30 wt.% KL exhibited similar thermo-mechanical properties and substantially enhanced antioxidant properties compared to the neat epoxy polymer. Additionally, the effect of the KL particle size was investigated. Ball-milled kraft lignin (BMKL, 10 μm) and nano-lignin (NLH, 220 nm) were, respectively, obtained after ball milling and ultrasonication and were studied as additives in the same epoxy system. Significantly improved dispersion and thermo-mechanical properties were obtained, mainly with nano-lignin, which exhibited fully transparent lignin–epoxy composites with higher tensile strength, storage modulus and glass transition temperature, even at 30 wt.% loadings. Lastly, KL lignin was glycidylized (GKL) and utilized as a bio-based epoxy prepolymer, achieving up to 38 wt.% replacement of fossil-based DGEBA. The GKL composites exhibited improved thermo-mechanical properties and transparency. All lignins were extensively characterized using NMR, TGA, GPC, and DLS techniques to correlate and justify the epoxy polymer characterization results. [ABSTRACT FROM AUTHOR]

This study aimed to ascertain the alterations in aging responses of fiber‐reinforced composites, as well as the effects of their natural particle reinforcement, through exposure to acidic and alkaline solutions. Specimens were produced with 0 wt. % (neat), 1 wt. %, 2 wt. % and 3 wt. % particle ratios from acorn and pinecone particles. A particle content of 2 wt. % was determined to yield the best mechanical properties in all mechanical tests conducted for pinecone reinforcement. The highest improvement in strength, observed in 3 wt. % pinecone‐reinforced composites, reached 22.5% at flexural strength. HCl and NaOH diluted in water were chosen as aging solutions. Mechanical tests were repeated at different stages of aging. According to the findings, 1 wt. % particle‐reinforced composites showed better resilience to the mechanical property reduction effect of aging compared to the 2 wt. % and 3 wt. % particle‐reinforced composites. At a particle ratio of 2 wt. %, the acorn‐reinforced specimens exhibit their highest maximum penetration force, which is 5% higher than that of the 0 wt. % composite, consistent with the results of tensile and compressive tests. Highlights: Composite material was manufactured by hand lay‐up and vacuum bagging method.Specimens were aged using acid and base solutions.Tensile, compressive, and bending results were obtained depending on particle type and ratio.Tensile, compressive, and bending strengths of composites were compared according to various aging times. [ABSTRACT FROM AUTHOR]

A co‐continuous 50:50 blend of poly(lactic acid) (PLA) and poly(butylene adipate‐co‐terephthalate) (PBAT) was compounded with 10–40 wt% hemp hurd microparticles (<250 μm) to achieve balanced material properties for additive manufacturing (3D printing) applications. The blend and composites were further compatibilized with maleic anhydride via an in situ reactive extrusion process to enhance the adhesion between the polymers and the fillers and subsequently improve stress transfer between the components. All composite samples were processed further via injection molding and 3D printing processes to analyze and compare the rheology, morphology, thermal, mechanical properties, and other physio‐chemical properties. For the unfilled polymer blends, the injection molded and 3D printed sample specimens displayed similar mechanical properties. However, in the hemp filled composites, the injection molded specimens demonstrated enhanced mechanical properties. This indicates that the 3D printing process requires further parameter optimization to eliminate potential gaps between the printing layers and enhance mechanical properties. Overall, the PLA:PBAT blends filled with hemp hurd microparticles provided balanced composite properties in addition to their sustainability attribute, which makes them an appealing alternative for the fabrication of compostable and tough materials via additive manufacturing processes. Highlights: Upon maleation, the blend components formed a co‐continuous morphology.Sustainable plastic filament with up to 40 wt% hemp hurd micro particles.3D printing can compete with injection molding in filled composites.Successfully 3D printed model furniture with 30 wt% hemp filler. [ABSTRACT FROM AUTHOR]

Polymer composites are mainly employed as an industrial material because of their chemical and corrosion resistance, especially in mining applications. As a result of the growing demand for biodegradable, ecological, and recyclable materials, organic fibres are widely used as reinforcement in polymer composites in recent years. The challenges arising from polymer composites, like environmental impact, moisture absorption, Thermomechanical property deterioration, lower durability in mining applications are discussed in this review. This work analyses the influence of certain physicochemical modifications on the reinforcement and matrix in polymer composites for mining purpose. This investigation was to understand the effectiveness of physicochemical modifications, specifically cryogenic treatment, on reinforcements and matrix to overcome the above mentioned challenges. This study also highlights the morphological and thermal changes due to the modifications. Results show the effect of these modifications on the composite and its constituents, cryogenic treatment on the organic fibre reinforcements showed increased moisture resistance, higher cellulose composition and mechanical properties, exposing the potential of using organic fibre-reinforced polymer composite in Mining applications. [ABSTRACT FROM AUTHOR]

Natural fibre reinforced composites have received a lot of interest in recent years as prospective building components for low-cost applications. Natural fibers offer good opportunity as composite reinforcement, as they are strong, light, cheap and renewable. Numerous experiments have been conducted to emphasize the use of bio-based materials for various applications. Considering environmental aspects, the current research is concentrated on bio-based binder and reinforcement. The objective here is to conduct various experiments for fire behaviour to justify its insulation property, fungal behaviour for degradability, moisture absorption and mechanical properties in order to tabulate results and to quantify the variations. Justify optimal composition and parameter responsible for variation by DOE-Taguchi technique. Experimental results presented reduction in burning rate with increase in Tamarind Seed Kernel Gum (TSG), attaining lowest of 8.29 mm/min at 60% Paper Cellulose (PC) and 40% TSG falling within the class of UL94HB for horizontal testing, 26.92 mm/min for vertical testing. The PC in combination with TSG influenced development of 'Mucore' category fungus resulting in rapid degradation, this is addressed by additives namely 'Boric Acid' and 'Turmeric Powder'. Poor performance observed in terms of moisture behaviour hampering the sustainability of composites. [ABSTRACT FROM AUTHOR]

This article aims to accomplish research's that has been achieved recently in the scientific community on the manufacturing monitoring and structural health monitoring (SHM) of composite materials using in-situ piezoelectric sensors. A series of specimens of flax/Elium composite laminates with and without integrated piezoelectric sensors were subject to static and fatigue tensile tests. The effects of introducing the sensor into the composite materials were studied. Moreover, the Acoustic Emission (AE) method was used during experimental tests to follow the gradual degradation and damage evolution in the bio-composites. The AE data were analyzed by the k-means unsupervised pattern recognition algorithm. Moreover, the characteristics of the acoustic signals detected from specimens with and without integrated sensors were compared. The experimental results show that the integration of piezoelectric sensors within the flax/Elium composite without degrading its mechanical properties is possible. In addition, the integrated sensor shows good results regarding class detection and separation. The in-situ health monitoring methods performed on bio-composites presents an excellent alternative to the conventional technique in which sensors are generally bonded to the material surface. [ABSTRACT FROM AUTHOR]

Beer bagasse is a residue waste produced in great amounts; nevertheless, it is still underestimated in the industry. The aim of this paper is to develop an innovative and efficient methodology to recycle the beer bagasse by producing Poly-lactic acid(PLA)-based bio-composites, in the forms of pellets and filaments, to be used in additive manufacturing processes. To assess the suitability of beer bagasse for extrusion-based 3D printing techniques, it was, firstly, physically and chemically characterized. Then, it was added in combination with different kinds of plasticizers to PLA to make bio-composites, analyzing their thermal and physical properties. The results prove the great potential of bagasse, evidencing its printability. Both composites' pellets and filaments were used in two different 3D printing machines and the mechanical properties of the 3D-printed models were evaluated as a function of the composition and the kind of technology used. All the used plasticizers improved processability and the polymer–bagasse interface. Compared to neat PLA, no changes in thermal properties were detected, but a lowering of the mechanical properties of the 3D-printed composites compared to the neat polymers was observed. Finally, a comparison between the efficiency of the two 3D printing techniques to be used with the bio-based composites was performed. [ABSTRACT FROM AUTHOR]

Transparent wood (TW)‐based materials have increasingly become the focus of researchers worldwide owing to their superior physico‐chemical‐optical properties, sustainable nature, as well as the fact that they are highly accommodating frameworks that can act as building blocks to readily explore a vast range of potential functionalities, holding great potential to displace glass and plastics in their various respective applications. The integration of multiple functionalities into TW has been undertaken to fulfill the demands of prospective sophisticated applications through the utilization of functional fillers or coatings. Herein, the up‐to‐date foundational developments and reports concerning emergent TW composites and coatings from a perspective of fabrication‐functionality‐application are comprehensively summarized, with a particular focus on seven specific functionalities; i) solar control; ii) chromically‐responsive, iii) electrically‐conductive, iv) shape‐memory active; v) flame‐retardant; vi) electromagnetic interference shielding; and vii) aesthetics. The potential applications of TW with these functionalities are also discussed. Finally, the current challenge with TW is addressed, as well as the future developments required for eventual real‐world application. [ABSTRACT FROM AUTHOR]

The application of bamboo fibers (BFs) as a reinforcing filler in polylactic acid (PLA) is hindered by their poor compatibility owing to the intrinsic hydrophilia of BFs and the hydrophobicity of PLA. To solve this issue, cardanol (CD) and epoxidized cardanol glycidyl ether (ECGE) were used as compatibilizers to strengthen and toughen PLA/BF bio‐composites, to the best of our knowledge, preparing PLA/BF/CD and PLA/BF/ECGE bio‐composites. The impact strengths of the synthesized bio‐composites increased from 7.75 to 23.75 and 7.75 to 23.95 kJ/m2, respectively, compared with that of a PLA/BF composite without compatibilizer. The investigation of the mechanical properties, crystallization, fractured surface morphology, and solvent stress‐cracking resistance properties revealed that the toughening mechanism of the PLA/BF/CD bio‐composites are mainly based on the plasticization of CD, which results in high impact toughness but low tensile strength. Moreover, the modification with ECGE improves the impact and tensile strengths of the bio‐composite owing to the following factors: (1) the epoxy groups of ECGE generate strong interactions with the BF surface and PLA to form an enhanced interfacial structure; (2) when present at high concentrations, chain extension reaction between ECGE and PLA to increase the molecular chain entanglement of PLA; and (3) upon curing and crosslinking, ECGE forms an entangled network structure that toughens the matrix. [ABSTRACT FROM AUTHOR]

In addition to being bio-degradable, cellulose nanocrystals (CNC) provide high mechanical strength to polymer composites. They exhibit outstanding properties like high strength-to-weight ratio, abundant surface functional groups and sustainability. In this study, we prepared nanocomposites of poly (ethylene-co-methyl acrylate) (EMA) and CNC using the melt-mixing technique. The mechanical properties of EMA were improved after adding CNC to it. The ultimate tensile stress and maximum elongation increased from 6 MPa and 860% (for pristine EMA) to 9.5 MPa and 1090% (for 2 wt.% EMA/CNC composite). Thermal properties of the EMA/CNC composites were analyzed by using DSC and TGA analysis. The dispersion of CNC in the composite was analyzed by SEM and XRD analyses. The EMA/CNC composites showed interesting birefringence properties on analysis via polarized optical microscopy (POM). The POM analysis indicated that the CNC in composites aligns themselves in the direction of applied stress, enhancing the mechanical strength of nanocomposites. Biodegradation of the bio-composite was also studied via soil-burial test. [ABSTRACT FROM AUTHOR]

Plant fiber-reinforced composites have the advantages of environmental friendliness, sustainability, and high specific strength and modulus. They are widely used as low-carbon emission materials in automobiles, construction, and buildings. The prediction of their mechanical performance is critical for material optimal design and application. However, the variation in the physical structure of plant fibers, the randomness of meso-structures, and the multiple material parameters of composites limit the optimal design of the composite mechanical properties. Based on tensile experiments on bamboo fiber-reinforced, palm oil-based resin composites, finite element simulations were carried out and the effect of material parameters on the tensile performances of the composites was investigated. In addition, machine learning methods were used to predict the tensile properties of the composites. The numerical results showed that the resin type, contact interface, fiber volume fraction, and multi-factor coupling significantly influenced the tensile performance of the composites. The results of the machine learning analysis showed that the gradient boosting decision tree method had the best prediction performance for the tensile strength of the composites (R2 was 0.786) based on numerical simulation data from a small sample size. Furthermore, the machine learning analysis demonstrated that the resin performance and fiber volume fraction were critical parameters for the tensile strength of composites. This study provides an insightful understanding and effective route for investigating the tensile performance of complex bio-composites. [ABSTRACT FROM AUTHOR]

Natural fiber‐reinforced composites are gaining increased interest for their significantly reduced carbon footprint compared to conventional glass or carbon fiber‐based counterparts. In this study, natural fibers are used in a resorcinol‐based epoxy resin that is thermally reshapable at higher temperatures (>180 °C) by using fast exchanging siloxane bonds, catalyzed by 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene. Stress relaxation times of only about 6 s at 220 °C can be reached. A resorcinol‐based epoxy compound is selected because it can be derived from cellulose, opening ways for more sustainable and reshapable composite materials. In a last step of the research, the low viscosity vitrimer formulation (<200 mPa s) is applied to make a flax fiber‐reinforced composite using an industrially relevant vacuum‐assisted resin infusion process. A section of this composite is successfully reshaped, which allows for envisioning a second life for natural fiber‐reinforced composites. [ABSTRACT FROM AUTHOR]

Understanding the wear mechanisms of a material subjected to varying loading conditions in various applications is a key to improve the overall performance of the material. Ceramic based composites when implemented as a bearing material under adverse loading conditions, performed very well but despite this clinical success, wear of these articulating surfaces continues to be one of the leading critical issues which need attention as this will influence the ultimate performance of the implant. Before any material can be used in joint arthroplasty, it is imperative to assess parameters that influence the wear performance of implant material as safety and efficacy are the main challenges. This review focuses and brings forth important aspects related to the wear performance of the ceramic‐based nanocomposites employed in joint bearings. This review presents a summary of wear rate data associated to bioceramic composite on the basis of past to recent published literature. [ABSTRACT FROM AUTHOR]

The continuous growth of the coffee market generates enormous amounts of spent coffee grounds (SCG), which account for up to 95 % of waste after coffee consumption. SCG contain a wealth of different resources that just need to be converted into another usable form. On the other hand, today’s excessive production of plastic waste in almost all industries worldwide is causing significant environmental pollution, leading to increased use of biodegradable polymers and bio-composites. Precisely because of the enormous amounts of SCG and the slow biodegradability of polylactide (PLA), this study aimed to investigate the properties and biodegradability of bio-composites made from green PLA and SCG, which were prepared by mixing the PLA matrix with different proportions of SCG. The thermal properties of the bio-composite were investigated by differential scanning calorimetry and thermogravimetric analysis. The particle size distribution of the SCG was studied by laser diffraction method, as well as the water absorption. The biodegradation of the bio-composite was carried out by a composting process of 19 days. The results of the thermal properties test showed that the SCG as filler did not affect the phase transitions of the PLA matrix, but it did affect the reduction of the thermal stability of the PLA_SCG bio-composite. The results of the water absorption test showed that increasing the amount of SCG leads to an increase in water absorption in biocomposites, due to the hydrophilic nature of the filler. On the light microscopic images, the surface attack of microorganisms was visible in bio-composites with lower SCG content, while deeper penetration was observed in bio-composites with higher SCG filler content. [ABSTRACT FROM AUTHOR]

In recent years, interest in sustainability has significantly increased in many industrial sectors. Sustainability can be achieved with both lightweight design and eco-friendly manufacturing processes. For example, concerns on the use of thermoset composite materials, with a lightweight design and a high specific strength, have arisen, since thermoset resins are not fully recyclable and are mainly petrol based. A possible solution to this issue is the replacement of the thermoset matrix with a recyclable or renewable matrix, such as bio-based resin. However, the mechanical properties of composites made with bio-based resin should be carefully experimentally assessed to guarantee a safe design and the structural integrity of the components. In this work, the quasi-static mechanical properties of composite specimens (eight layers of carbon fiber fabric) made with commercially available epoxy and a bio-based epoxy resins (31% bio content) are compared. Tensile tests on the investigated resins and tensile, compression, shear and flexural tests have been carried out on composite laminates manufactured with the two investigated resins. A finite element model has been calibrated in the LS-Dyna environment using the experimentally assessed mechanical properties. The experimental results have proven that the two composites showed similar quasi-static properties, proving that bio-based composite materials can be reliably employed as a substitute for epoxy resins without affecting the structural integrity of the component but lowering their carbon footprint. [ABSTRACT FROM AUTHOR]

In this work, rice straw fibers were modified using NaOH, KBM-403, and tetraethyl orthosilicate (TEOS), and the changes in the surface groups of the straw fibers before and after the modification were analyzed by infrared testing. Straw/polylactic composite were prepared by hot pressing, and the effects of the modifiers used on the properties of these blends were studied by conducting mechanical and thermal performance tests. The results showed that the tensile strength of the straw fiber composites modified by NaOH and KBM-403 increased by 20% and 21.2%, respectively, compared with that of the unmodified composite, whereas the tensile strength of the TEOS-modified fiber did not increase significantly. The flexural strengths of the composites increased by 10.2%, 11.1%, and 13.2%. The impact strength increased by 38.5%, 7.6%, and 7.6%. The results of thermal analysis show that initial and maximum thermal decomposition temperatures of the composite materials increased, indicating that the modified composite materials had a higher thermal stability. These blends are a kind of potential material for structural applications such as interiors, drywell and partitions for furniture. [ABSTRACT FROM AUTHOR]

Bone plates are essential for bone fracture healing because they modify the biomechanical microenvironment at the fracture site to provide the necessary mechanical fixation for fracture fragments. This paper focuses on reducing the stress shielding effect that occurs due to a mismatch between cortical bone and metal plate. fabricating bio composites plates fixation by modeling of femur bone with ANSYS software program. However, Bio-composites that involve Ultra-high molecular weight polyethylene polymer (UHMW-PE) reinforced with nano Titanium dioxide particles n-TiO2 at different fractions (0, 1.5, 2.5, 3.5 and 4.5%) and 5% from carbon and Kevlar fibers were fabricated by hot pressing technique. We tested tensile, elastic modulus, and elongation percentages. The results of this study showed a value of tensile strength and elastic modulus improved with increasing weight fraction of nanoparticles and UHMWPE+4.5% n-TiO2 biocomposite were the best mechanical properties, were tensile strength and elastic modulus was (38.57 ± 1.9285 MPa, 1.15 ± 0.0575 GPa) respectively and elongation percentages reduced to 114.05 ±5.7025% compared with pure UHMWPE 176.68 ± 5.7025%. According to the current study's findings, it is possible to create bio-composites as fixation devices with improved performance by placing different fiber reinforcements. [ABSTRACT FROM AUTHOR]

Foam materials are widely used in packaging and buildings for thermal insulation, sound absorption, shock absorption, and other functions. They are dominated by petroleum‐based plastics, most of which, however, are not biodegradable nor fire‐proofing, leading to severe plastic pollution and safety concerns. Here, a fire‐proofing, thermally insulating, recyclable 3D graphite‐cellulose nanofiber (G‐CNF) foam fabricated from resource‐abundant graphite and cellulose is reported. A freeze‐drying‐free and scalable ionic crosslinking method is developed to fabricate Cu2+ ionic crosslinked G‐CNF (Cu‐G‐CNF) foam with a low energy consumption and cost. Moreover, the direct foam formation strategy enables local foam manufacturing to fulfil the local demand. The ionic crosslinked G‐CNF foam demonstrates excellent water stability (the foam can maintain mechanical robustness even in wet state and recover after being dried in air without deformation), fire resistance (41.7 kW m−2 vs 214.3 kW m−2 in the peak value of heat release rate) and a low thermal conductivity (0.05 W/(mK)), without compromising the recyclability, degradability, and mechanical performance of the composite foam. The demonstrated 3D G‐CNF foam can potentially replace the commercial plastic‐based foam materials, representing a sustainable solution against the "white pollution". [ABSTRACT FROM AUTHOR]

The widespread use of plastics in seedling production, due to their convenience and cost-effectiveness, poses significant environmental challenges, including pollution and high resource consumption. To address these issues, a sustainable hybrid bio-composite was developed using bio-polybutylene succinate (PBS) combined with canabrava fibers (Cana) (up to 30 wt%), lignin (Lig), montmorillonite (MMT), and sepiolite (SEP). This bio-composite, featuring a negative carbon footprint and fully biodegradable components, offers a promising alternative to polypropylene packaging in seedling production, enhancing environmental sustainability and promoting the valorization of waste materials like Cana and Lig. The bio-composites were synthesized via melt blending in an extruder, and their mechanical, thermal, and morphological properties were evaluated. The melt flow rate could be effectively managed by adjusting the combination of Cana, Lig, and clays, achieving values comparable to polypropylene (EP440L). Notable enhancements in mechanical properties were observed relative to neat PBS, with increases in Young's modulus (up to 353 %), yield stress (up to 198 %), flexural modulus (up to 390 %), and flexural strength (up to 160 %). These improvements are mainly attributed to the high Cana fiber content and the hybrid effects of clays, particularly SEP. However, reductions in impact resistance and elongation were noted compared to neat PBS and EP440L, likely due to limited fiber-polymer interactions and increased compactness as observed in SEM analysis. FT-IR analysis indicated strong interactions between clays and PBS, evidenced by a shoulder at 1602–1608 cm−1. XRD analysis suggested the exfoliation of MMT, as indicated by the absence of the (001) plane reflection, although the high content of Cana may have mitigated some mechanical benefits. DSC analysis revealed increased crystallinity with the incorporation of Cana, Lig, and clays, likely driven by nucleation effects. The presence of SEP was associated with a secondary melting peak, indicating effective dispersion and interfacial crystal formation. Enhanced thermal stability was demonstrated by a higher temperature at 90 % mass loss compared to neat PBS. These findings suggest the bio-composite is a sustainable alternative for reducing plastic waste in seedling production. [Display omitted] • Eco-friendly PBS composites with canabrava fiber, lignin, and clay minerals. • Canabrava (30 %) improved Young's modulus (+353 %) and yield stress (+198 %). • Sepiolite slightly improved mechanical properties and ensured good clay dispersion. • Enhanced thermal stability with higher crystallinity and melting temperature. • Lignin increased melt flow, balancing canabrava's effect on fluidity reduction. [ABSTRACT FROM AUTHOR]

Bio-composite foams based on Epoxidized Natural Rubber (ENR) filled with lignin (LG) and ammonium polyphosphate (APP) were fabricated via batch foaming. The addition of APP accelerated the foaming process at lower temperatures. Pre-mixing induced ionic and hydrogen bonding between the LG and the APP particles, which reduced crosslinking between LG and ENR. The resulting ENR bio-composite foams with LG/APP exhibited a significant increase in compressive strength (up to 700 %) and modulus (up to 600 %) compared to the ENR foam baseline. Furthermore, the LG/APP foams demonstrated lower thermal conductivity than both the ENR foam baseline and foams containing only LG or APP, attributed to optimal thermal conduction in the solid phase and convection within the pore cells. The combination of APP and LG produced synergistic effects, with phosphorus (from APP) and high carbon content (from LG) enhancing flame-retardant efficiency. This study highlights the potential of these sustainable bio-composite foams for applications requiring enhanced thermal insulation and flame retardancy attributes for insulation and other practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA)-based biocomposites were fabricated by the incorporation of chitosan (Ch), cellulose fibers (CS), and their mixture (1:1 ratio). Fillers with various loading (2, 4, 8, and 10 wt.-%) were incorporated into PVA employing the solution casting method. The fillers and biocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), brightfield microscopy, tensile and microindentation tests, contact angle measurement and thermogravimetric analysis (TGA). FTIR spectra revealed the removal of lignin, and intermolecular H-bonding between PVA and fillers promoting their filler–matrix interfacial interactions. Crystallographic results showed varied crystallite sizes and crystallinity of composites. Microscopic techniques revealed a uniform filler distribution, attributed to their compatibility with PVA. Tensile and microindentation tests demonstrated a decreased tensile strength (3.3–8.2 MPa of the composites compared to 15.7 MPa of the matrix) and Martens hardness (HM) of biocomposites. However, their value was increased with higher filler concentration, signifying the mechanical reinforcement. Contact angle analysis confirms the decreased wettability (hydrophilicity) of biocomposites, attributed to higher compatibility of fillers with PVA and intermolecular H-bonding between them. A slightly decreased thermal stability of biocomposites with filler incorporation is implied by TGA results despite their uniform distribution and strong matrix–filler interfacial interactions. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA)-based biocomposites were fabricated by the incorporation of chitosan (Ch), cellulose fibers (CS), and their mixture (1:1 ratio). Fillers with various loading (2, 4, 8, and 10 wt.-%) were incorporated into PVA employing the solution casting method. The fillers and biocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), brightfield microscopy, tensile and microindentation tests, contact angle measurement and thermogravimetric analysis (TGA). FTIR spectra revealed the removal of lignin, and intermolecular H-bonding between PVA and fillers promoting their filler–matrix interfacial interactions. Crystallographic results showed varied crystallite sizes and crystallinity of composites. Microscopic techniques revealed a uniform filler distribution, attributed to their compatibility with PVA. Tensile and microindentation tests demonstrated a decreased tensile strength (3.3–8.2 MPa of the composites compared to 15.7 MPa of the matrix) and Martens hardness (HM) of biocomposites. However, their value was increased with higher filler concentration, signifying the mechanical reinforcement. Contact angle analysis confirms the decreased wettability (hydrophilicity) of biocomposites, attributed to higher compatibility of fillers with PVA and intermolecular H-bonding between them. A slightly decreased thermal stability of biocomposites with filler incorporation is implied by TGA results despite their uniform distribution and strong matrix–filler interfacial interactions. [ABSTRACT FROM AUTHOR]

This study presents the design and synthesis of bio-composites exhibiting high properties, wherein both the matrix and filler originate from wood biomass. Notably, no additional hardener compounds or treatments/modifications of the lignocellulosic filler were employed. Thermosetting materials were developed by homopolymerizing a bio-based aromatic epoxy monomer, the resorcinol diglycidyl ether (RDGE), with different percentages, from 1 wt% to 30 wt% of natural wood processing side-product, such as spruce bark powder (SB), which was used as such without additional treatments and modifications. The DSC analyses revealed enhanced reactivities with the bio-filler content, resulting in a reduced reaction temperature range and maximum reaction temperature. These findings provide evidence of the chemical interaction between the functional groups from spruce bark and the epoxides groups. The obtained fully based lignocellulosic materials show high E ' values from 2.4 GPa to 2.5–3.5 GPa (glassy state) and from 64 MPa to 99–156 MPa in the rubbery region. The damping factor of the bio-composites with 1–10 wt% SB have shown an increase of the α transition temperature from 92 °C to 94–97 °C. The excellent filler/matrix interface and optimal adhesion between them were confirmed by SEM analysis. [ABSTRACT FROM AUTHOR]

Utilizing agro-residues as organic fillers instead of wood is considered a sustainable option for preserving forestry. Recently, we successfully developed a new chemical treatment method to extract rich cellulosic microfibers from agro-residues of date palm trees. The treated fibers exhibited an improved performance, thus demonstrating the prominent potency of the new method. For further confirmation, in this study, we have applied the technique to treat raw microfibers and examine their performance as reinforcing elements in both virgin polypropylene (PP) and recycled post-consumer polypropylene (rPP). The chemically treated fibers were initially pulverized to a powder form using a ball milling machine and then blended with PP or rPP to make bio-composites. Specimens were fabricated at melt state using a single-screw extruder followed by compression molding. Then, a series of mechanical and physical tests were conducted on the specimens following ASTM standards. Results revealed that incorporating treated fillers into either PP or rPP has enhanced the mechanical properties of the bio-composite compared to the ones with untreated filler. Owing to the treatment, the rise in tensile strength of recycled polymer-based bio-composites was higher than that of virgin polymer-based bio-composites where treated fillers acted effectively as a nucleation agent to rPP. Additionally, a pronounced drop in water absorption and boost in crystallinity of both bio-composites were attained. However, thermal degradation was not dramatically altered. Therefore, this study showed that reinforcing rPP with treated date palm filler to make bio-composites is a reliable route for designing products across a wide range of industries. • Developed novel chemical treatment to improve bonding between fiber and polymer in bio-composite. • Achieved better fiber connectivity with matrix through chemical crosslinking. • Demonstrated a significant improvement in tensile properties for treated bio-composites. • Highlighted the method's potential to promote high-performance bio-composite materials. [ABSTRACT FROM AUTHOR]

Brewer's spent grain (BSG), the by-product of the brewery, serves as a significant reservoir of lignocellulose and protein. In the present work, three fractions rich in protein-lignin (Pr-Lig), hemicellulose (HC), and nanocellulose (NC) were extracted from BSG through a sequential biorefinery process. Then, two distinct composites of Pr-Lig or HC containing various NC content (3, 5, and 7 % wt) were fabricated. The composite properties including surface/chemical structures, moisture sensitivity, tensile, optical, and bioactive properties were then assessed. Results showed that HC-based film possessed higher tensile strength (5.2 MPa), Youngs' modulus (45 MPa), water vapor permeability (0.83×10−10 g m−1 s−1 Pa−1), and water solubility (79.75 %) than Pr-Lig-based composites. Conversely, the Pr-Lig-based composite exhibited higher ultraviolet barrier, DPPH scavenging activity (47.71 %), and antibacterial activity against Escherichia coli (21.03 %) and Staphylococcus aureus (63.67 %) due to the presence of polyphenolic lignin. The inclusion of NC resulted in significant improvements in water vapor barrier (18.07 and 41.30 %), water solubility (16.13 and 14.83 %), tensile strength (57.21 and 61.90 %), and Young's modulus (201.84 and 170.13 %) of both HC and Pr-Lig composites, respectively due to the crystalline nature of NC and the potential hydrogen bonding. Nevertheless, the elongation of the Pr-Lig nanocomposite was reduced by 45.83 % after the inclusion of NC. Investigation of the freshness indexes of blueberries coated by BSG-derived composites indicated a significant preservation effect by delaying fruit decay and prolonging the shelf life for 12 days. This study contributes to advancing the sustainable materials and packaging domain by highlighting a cascade biorefinery of lignocellulosic biomass and showcasing the potential of BSG as a valuable resource to develop active packaging. Further investigations into environmental assessments at various stages of biorefinery, fabrication, and end-of-life, compared to conventional plastics, along with safety analyses, can contribute to broadening the application of BSG-derived composites in various fields. [Display omitted] • Brewer's spent grain (BSG) is valorised through a cascade biorefinery approach. • Lignin-protein and hemicellulose composite containing nanocellulose are developed. • Lignin-protein-based films show maximum antibacterial and antioxidant activity. • Hemicellulose-based films display higher tensile and moisture sensitivity. • BSG-derived composite coatings can extend the shelf-life of blueberries. [ABSTRACT FROM AUTHOR]

Significant interest for utilizing and processing natural fibers (NF) to develop sustainable and fully biodegradable composites evolved as the global environmental concerns upsurge. Date palm tree (DPT) accounts for more than 2.8 million tons of waste annually, making it the most abundant agricultural biomass waste in the MENA region. This study investigates the effect of date palm fiber (DPF) density, diameter size and content on both the mechanical and physical properties of polylactic acid (PLA) reinforced DPF bio-composite. The bio-composites are developed using melt-mixing technique which is followed by compression molding. The influence of the mechanical properties is investigated by evaluating the tensile, flexural and impact strengths. Meanwhile bio-composite thickness swelling (TS), moisture content (MC) and water absorption (WA) characteristics are evaluated. Bio-composite microstructures are examined using SEM to investigate the interfacial bonding between PLA matrix and DPF. Results showed that at 40 wt.% DPF, the TS, MC, and WA were the highest demonstrating an increase of 4.10%, 4.95%, and 8.22%, respectively. Although the results demonstrated a decrease in mechanical properties as DPF content increased (depending on DPF geometry), the results indicate that the developed technologies could be commercialized under the waste management scheme for non-structural applications. [ABSTRACT FROM AUTHOR]

An eco-friendly epoxy/thiol-ene photopolymerization (ETEP) process was employed to prepare epoxy bio-composites using a commercial biobased epoxy resin and a woven jute fabric as reinforcement. In this process the components of the thiol-ene system, an allyl-functionalized ditertiary amine curing agent, a multifunctional thiol and a radical photoinitiator, were added to the epoxy resin to produce a polyether–polythioether crosslinked co-network. Moreover, the jute fibers were functionalized with thiol groups using the 3-mercaptopropyl (trimethoxysilane) with the purpose of creating a chemically bonded polymeric matrix/fiber system. The obtained bio-composites prepared with the thiol-functionalized cellulose fibers exhibited an increase up to 52% and 40% in flexural modulus and strength with respect to the non-functionalized counterparts. Under the three-point bending loadings, the composites displayed higher deformation at break and toughness due to the presence of polythioethers in the co-network. The prepared bio-composites developed in this work are excellent candidates to extend the use of cellulose fibers for structural applications. [ABSTRACT FROM AUTHOR]

In recent years, one of the main challenges is to improve the mechanical performance of bio-composites to be used as structural parts for the construction, automotive, and aviation sector. This paper may contribute to developing durable structural bio-composite parts with starch addition. The mechanical properties of bio-composites reinforced by eucalyptus or pine fibers (48 wt %) compound with Cationic Starch (48 wt %) and Carboxymethyl cellulose (CMC) (4 wt %) were determined. The production method was a combination of molded pulp, extrusion, and compression molding production techniques. To see the effect of adding starch to bio-composites and different production methods, the mechanical performance of these natural fibers produced by the conventional molded pulp production method (without any additives) was also found and compared with the composite samples. Composite samples indicate significantly better tensile, flexural, and compressive values, at least four times, compared with the molded pulp samples. On the other hand, the molded pulp samples had more than 2 times better impact characteristics against composites. Using molded pulp technic in composite production (investigated in the study) is a new idea and may give some opportunities with its serial production compatibility and geometry freeness, to the industry. [ABSTRACT FROM AUTHOR]

This work aims to investigate the degradation stability of bamboo fiber-reinforced polyester composite toughened with complex lignin biopolymer derived from the waste grape stalks. The properties like mechanical, wear, thermal, DMA, and hydrophobic were studied after the addition of lignin and analyzed how the lignin addition influenced these properties. Prior to composite making the fiber and lignin was treated with silane. According to the results obtained incorporating 40 vol% of bamboo fiber into the polyester resin, the mechanical and wear properties enhanced. Further, the composite containing 2.0 vol% of lignin has maximum tensile strength, tensile modulus, flexural strength, flexural modulus, and ILSS. Similarly, the composite designation having 4 vol% lignin revealed the improved wear loss stability of 0.007 mm3/Nm (sp. wear rate). The highest degradation temperature reported for composite designation UBL4 it was 520 °C, with a relatively lesser weight loss of 19 %. Likewise, the highest storage modulus was about 4.5 GPa, and the lowest loss factor was up to 0.3 for the composite designation UBL4. The contact angle investigation revealed that all composite designations are not fall below 70°, indicating their hydrophobic stability. These composites with enhanced stability against load, heat and water could be utilized in the industrial, automotive and defense sectors where high performance outcomes are required. [ABSTRACT FROM AUTHOR]

Keywords: Cocos nucifera peduncle; natural cellulosic fiber; bio-composites; characterization; polymer matrix composites; sustainability; ; ; ; ; ; EN Cocos nucifera peduncle natural cellulosic fiber bio-composites characterization polymer matrix composites sustainability ZH 9373 9383 11 11/21/22 20221220 NES 221220 Introduction Currently, the utilization of natural fibers in the composite industry is being increased due to its low cost, low density, high toughness, eco-friendly, biodegradable, and good specific properties. The presence of lignin 24.9 wt.% in CTPF enhances the bonding of fibers with polymers when used as reinforcement in polymer matrix composites. Nevertheless, in order to optimize the performance of polymer composites, knowledge of mechanical, thermal, physical and chemical properties of natural fibers are indeed essential for evidencing its assets in terms of novel composite products. Natural cellulosic fiber, Cocos nucifera peduncle, bio-composites, characterization, polymer matrix composites, sustainability. [Extracted from the article]

在汽車行業的許多結構和非結構應用中，NFRC（天然纖維增強複合材料）被證明是現有玻璃/碳纖維增強複合材料的潛在材料替代品。本文介紹了兩種不同取向 [90°/0°/0°/90°] 和 [45°/0°/0°/45 °]，使用錐形衝擊器承受 10.24 J 的衝擊能量。基於作為能量吸收處理的力-時間響應和衝擊能量-時間歷史來評估它們的性能和損傷特性。還進行了掃描電子顯微鏡 (SEM) 分析以研究斷裂表面的微觀結構信息並與最可能的故障原因相關聯。照片和 SEM 圖像證實了纖維主要失效。實驗結果表明，與交叉層相比，角層取向複合材料吸收了更多的能量。發現交叉層比較硬，因為它不太容易損壞. [ABSTRACT FROM AUTHOR]

Thermal insulators have a crucial role in reducing the operational building energy. They are commonly fabricated from petrochemical materials that mostly cause negative environmental impacts. This study aims to develop banana leaves-polystyrene composites (BL-PS) as a sustainable and low-cost thermal insulator. The BL powder was mixed with PS in different weight ratios (90:10, 80:20, 70:30, and 60:40). Thermal conductivity, electrical conductivity, SEM, XRD, FTIR, TGA, and DSC were carried out on BL and BL-PS composites that were prepared with 10 wt.% of PS powder (BL-PS1) and 30 wt.% of PS powder (BL-PS3). The prepared composites show low thermal conductivity, ranged from 0.0183 to 0.03168 W/m.K. The least thermal conductivity 0.0183 W/m.K was recorded for the BL-PS1 with high crystallinity and thermal stability. The present findings may support the validity of using banana leaves composite to produce an eco-friendly inexpensive thermal insulating material. [ABSTRACT FROM AUTHOR]

This paper reports the mechanical properties of PLA composites incorporated with tamarind and date seed Micro fillers. The composites were manufactured through compression molding technique. The tensile results showed that the seed filler reinforcement has significantly improved the tensile strength of PLA matrix. The particulate reinforcements of both tamarind and palm almost doubled the flexural and impact strength of PLA matrix. Moreover, the date seed powder incorporated composites showed 34.68% improvement in micro hardness but the tamarind seed powder composite showed only marginal improvement (9.82%) when compared with neat PLA. Furthermore, the outcomes revealed that the wt.% of fillers play a noteworthy role in deciding the properties of the PLA composites. [ABSTRACT FROM AUTHOR]

Increasing global environmental problems and awareness towards the utilization of eco-friendly resources enhanced the progress of research towards the development of next-generation biodegradable and environmentally friendly material. The development of natural-based composite material has led to various advantages such as a reduction in greenhouse gases and carbon footprints. In spite of the various advantages obtained from green materials, there are also a few disadvantages, such as poor interfacial compatibility between the polymer matrix and natural reinforcements and the high hydrophilicity of composites due to the reinforcement of hydrophilic natural fibers. This review focuses on various moisture-absorbing and sound-absorbing natural fiber polymer composites along with the synopsis of preparation methods of natural fiber polymer composites. It was stated in various studies that natural fibers are durable with a long life but their moisture absorption behavior depends on various factors. Such natural fibers possess different moisture absorption behavior rates and different moisture absorption behavior. The conversion of hydrophilic fibers into hydrophobic is deemed very important in improving the mechanical, thermal, and physical properties of the natural-fiber-reinforced polymer composites. One more physical property that requires the involvement of natural fibers in place of synthetic fibers is the sound absorption behavior. Various researchers have made experiments using natural-fiber-reinforced polymer composites as sound-absorbing materials. It was found from various studies that composites with higher thickness, porosity, and density behaved as better sound-absorbing materials. [ABSTRACT FROM AUTHOR]

Dielectric analyses were investigated on vinyl resin emulsion based on ethylene vinyl acetate/vinyl ester of versatic acid terpolymer (EVA/VeoVa) and its composites reinforced with microcrystalline cellulose and multi-wall carbon nanotubes. Dielectric spectra were measured in the frequency range from 10-1 Hz to 107 Hz and the temperature interval from -35°C to 130°C. Three dielectric relaxations were identified for the matrix. The first one, appearing at lower temperatures and higher frequencies, was associated with secondary β relaxation. The second one appearing above the glass transition temperature was attributed to the α relaxation due to the main glass transition of the terpolymer. The third dielectric relaxation appearing at higher temperatures and lower frequencies was attributed to α' relaxation originating from the motion of more repeat units compared to the α one. The addition of the reinforcements into the matrix gave rise to three additional dielectric phenomena originating either from microcrystalline cellulose or matrix/reinforcement interfaces. Analyses of secondary dielectric relaxations at low temperatures by using the Havriliak-Negami model and those at high temperatures according to an adequate equivalent circuit model allowed probing reinforcement/matrix interactions. This dielectric study was complemented by the thermal, structural and morphological analyses based on differential scanning calorimeter (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively [ABSTRACT FROM AUTHOR]

The main objective of this work was to estimate the usefulness of response surface methodology (RSM) and genetic algorithm (GA) in modeling and predicting the strength of jute/poly(lactic acid) (PLA) composite laminates. Firstly, the impact of the hot water treatment on the thermal, molecular structure, and morphological characterizations as well as kinetic analysis of jute fibers were performed by Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM). The FTIR results showed that the hot water treatments reduced the content of lignin, hemicellulose, and impurities of the fibers. Hot water treated fibers exhibited higher thermal stabilities compared with untreated fibers as shown with TGA results. The SEM results showed effect contact surface area improved after the hot water treatment, leading to better mechanical properties of bio‐composites. Secondly, the influences of the ply orientation, plies and fiber content on the tensile strength and flexural strength of the hot water treated fibers composites were evaluated by RSM. RSM with the Box Behnken Design was utilized to establish the quadratic models of two objectives in response to input parameters. Analysis of variance (ANOVA) was used to determine percentage contribution of various parameters on two quality objectives. According to the ANOVA results, ply orientation had the most important impact on tensile strength while the ply orientation‐fiber content interaction had the most important impact on flexural strength. Finally, multi‐objective optimization was carried out to maximize tensile strength and flexural strength using the desirability function and GA. The optimized results both showed an acceptable relative error between experimental and optimized values. [ABSTRACT FROM AUTHOR]

Additive manufacturing can be a valuable tool to process polymeric composites reinforced with bio-based fibres, extending their use and opening new opportunities for more environmentally friendly materials. In this work, poly(lactic acid) (PLA) composites reinforced with regenerated cellulose fibres (lyocell) were processed into novel filaments and used for 3D printing. The Young's modulus of the filaments increased with the addition of fibres, but substantial porosity was observed in formulations with 20 and 30 wt% of fibre content. Nonetheless, the composites were easily printed, and the formulation with 10 wt% of fibres presented the best tensile properties of 3D printed samples with average tensile strength, Young's modulus, and strain at break of 64.2 MPa, 4.56 GPa, and 4.93%, respectively. It has been shown in this study that the printing process contributes to fibre alignment with small variations depending on the printing speed. Printed composite samples also had superior thermo-mechanical stability with a storage modulus up to 72 times higher than for neat PLA at 80 °C after the composite samples were heat-treated. In general, this work supports the potential use of regenerated cellulose fibres to reinforce PLA for 3D printing applications. [ABSTRACT FROM AUTHOR]