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Abstract A novel, promising biocomposite was synthesized through the free radical polymerization method using methyl methacrylate (MMA), acrylic acid (AA), and hydroxyapatite derived from oyster shells (Os‐HA). Fourier transform infrared spectroscopy (FTIR) peaks indicate the conjugation of Os‐HA in the biocomposite. From the TGA analysis, it was observed that a weight loss of nearly 2% is achieved at 210°C, up to 15% at 210 to 420°C, and up to 95% at 420 to 580°C. The SEM image shows the uniform dispersion of the Os‐HA particles and strong interaction with the copolymer matrix. The broad spectrum at 2θ = 14.6° in XRD analysis indicates the amorphous nature of poly(MMA‐co‐AA)/Os‐HA. The higher inhibition zone of the biocomposite is observed at 125 μL against E. coli bacteria. The maximum water absorption is observed at 15 wt% of Os‐HA. The young's modulus gradually increases, while the impact strength decreases up to 20 wt% of Os‐HA. The artificial neural network (ANN) model has been used to assess the optimum values of impact strength, tensile strength, and Young's modulus of the biocomposite material. The correlation factor (R = 0.998) of the ANN model data indicates greater accuracy of the experimental result.

The enhancement of the mechanical and thermal characteristics of 3D printed polylactic acid (PLA) composites reinforced by coir fiber powder (CFP) has been investigated by varying the weight percentage (wt%) of the reinforcement and annealing process. CFP/PLA composite filaments with CFP compositions of 0.1, 0.3, and 0.5 wt% were fabricated. These filaments were used to print CFP/PLA test specimens. The specimens were annealed at 90°C for 120 min in a hot air oven followed by cooling at room temperature. Mechanical, morphological, crystalline, and thermal characterizations were conducted on these specimens. The tensile and flexural strength of neat PLA were observed as 49.7 and 82.4 MPa which decreased by 6.4% and 8.13% respectively for printed composite specimens with 0.5 wt% CFP as reinforcement material. On the other hand, the annealed CFP/PLA composite specimen, with 0.1 wt% CFP as a reinforcement material, demonstrated higher tensile and flexural strength. Specifically, it exhibited a maximum tensile strength of 56.4 MPa and a maximum flexural strength of 92.9 MPa, which are 13.5% and 12.7% higher, respectively, than neat PLA. These strengths are 15.5% and 16.7% higher, respectively, than those of the unannealed CFP/PLA composite specimen with the same wt% of CFP reinforcement. The annealing process increased the crystallinity of composites by enhancing the crystallinity index (63%) and crystalline size (6.7 nm). The high thermal stability of composites (with a glass transition temperature of 256°C) makes them suitable for applications in food and medical packaging. Highlights: Enhancement of thermo‐mechanical characteristics of 3D printed bio‐composites.Annealing process improved mechanical features of 3D printed bio‐composites.Annealed composite with 0.1 wt% as reinforcement demonstrated better properties.SEM and XRD studies confirmed failure mechanisms and crystalline structure.Thermal and mechanical assets favor its utilization in food wrapping applications. [ABSTRACT FROM AUTHOR]

Biopolymers are biodegradable and renewable and can significantly reduce environmental impacts. For this reason, biocomposites based on a plasticized starch and cross-linker matrix and with a microfibrillated OCC cardboard cellulose reinforcement were developed. Biocomposites were prepared by suspension casting with varied amounts of microfibrillated cellulose: 0, 4, 8, and 12 wt%. Polyethylene glycol diglycidyl ether (PEGDE) was used as a cross-linking, water-soluble, and non-toxic agent. Microfibrillated cellulose (MFC) from OCC cardboard showed appropriate properties and potential for good performance as a reinforcement. In general, microfiber incorporation and matrix cross-linking increased crystallization, reduced water adsorption, and improved the physical and tensile properties of the plasticized starch. Biocomposites cross-linked with PEGDE and reinforced with 12 wt% MFC showed the best properties. The chemical and structural changes induced by the cross-linking of starch chains and MFC reinforcement were confirmed by FTIR, NMR, and XRD. Biodegradation higher than 80% was achieved for most biocomposites in 15 days of laboratory compost. [ABSTRACT FROM AUTHOR]

The escalating significance of 3D printing in various industries is underscored by its ability to rapidly and cost-effectively produce distinctive parts. Among the 3D printing methods, fused filament fabrication (FFF) has emerged as a highly productive and cost-effective approach. While extensive efforts have been made to enhance the qualities of FFF products, challenges persist in material availability and quality compared to traditional methods. This study provides a meticulous overview of the FFF process, delving into various 3D printing processes, polymers, and polymer composites. Despite documented efforts to augment mechanical, thermal, and electrical properties, material constraints remain a focal point. Our analysis extends to various PLA/biocomposites, shedding light on achieved improvements and potential applications. Looking forward, the future trend in FFF technology suggests a paradigm shift towards enhanced material diversity and performance. Anticipated applications span beyond traditional use cases, encompassing sustainable manufacturing, medical devices, and eco-friendly construction materials. This comprehensive review not only consolidates the current state of FFF and PLA-biocomposites but also anticipates future trends and potential applications. This research enhances the current knowledge of additive manufacturing and sets a standard for assessing developments in FFF technology by comparing them to previous works. [ABSTRACT FROM AUTHOR]

In the evolving field of bioproducts, materials that synergize sustainability with functionality are of paramount importance. Mycelium composites, derived from intricate networks of fungal filaments, are gaining traction as innovative bioproducts that offer a compelling blend of eco‐friendliness, renewability, and adaptability. As the quest intensifies for alternatives that can mitigate the environmental toll of conventional products, mycelium‐based solutions are emerging as beacons on the sustainable bioproducts horizon. Their transition from niche innovations to mainstream applications depends on their ability to overcome a series of fabrication challenges. This review paper investigates the critical challenges faced in the fabrication of mycelium composite. It examines rigorously some essential factors leading to fabrication failure, such as contamination, inconsistent growth, insufficient moisture, inappropriate pH, and improper substrate preparation. The review offers a comprehensive analysis of each factor influencing mycelium growth and the resulting composite properties, with an emphasis on preventative and mitigating strategies. Through an in‐depth exploration of case studies detailing unsuccessful mycelium composite fabrication, the significance of understanding these failure factors is emphasized. The paper culminates in a forward‐thinking discourse on potential strategies for refining fabrication processes, and identifies promising research areas poised to enhance both the success rate and overall efficiency of mycelium composite production. [ABSTRACT FROM AUTHOR]

Plastic containers, commonly produced from non-biodegradable petroleum-based plastics such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET), raise significant environmental concerns due to their persistence. The disposal of agricultural waste, specifically rice straw (RS), through burning, further compounds these environmental issues. In response, this study explores the integration of polylactic acid (PLA), a biodegradable material, with RS using a twin-screw extruder and injection process, resulting in the creation of a biodegradable packaging material. The inclusion of RS led to a decrease in the melt flow rate, thermal stability, and tensile strength, while concurrently enhancing the hydrophilic properties of the composite polymers. Additionally, the incorporation of maleic anhydride (MA) contributed to a reduction in the water absorption rate. The optimized formulation underwent migration testing and met the standards for food packaging products. Furthermore, no MA migration was detected from the composite. This approach not only provides a practical solution for the disposal of RS, but also serves as an environmentally-friendly alternative to conventional synthetic plastic waste. [ABSTRACT FROM AUTHOR]

Polylactic-acid–starch-based polymer composite (PLA/TPS) has good thermal stability for biocomposites. However, the physical and mechanical properties of PLA/TPS do not meet the standards. It needed additives to enhance its physical and mechanical properties. The aim was to improve the physical and mechanical properties of PLA/thermoplastic starch using sucrose. In addition, this study evaluated the enhancement of thermal properties of PLA/thermoplastic starch using sucrose. This study used sucrose as an additive to enhance the PLA/TPS composite. The addition of sucrose inhibits the degradation of biocomposites. This means that thermal stability increases. The thermal stability increased because the degree of crystallinity increased with the addition of sucrose, which was also proven in the XRD result. The addition of sucrose caused the morphology of the biocomposite to have pores. The FESEM results showed that biocomposites with the addition of sucrose had pores and gaps. These gaps result from low adhesion between polymers, causing a decrease in the mechanical and physical properties of the sample. Based on the FTIR spectra, biocomposite PLA/TPS blends with the addition of sucrose still have many hydroxyl groups that will lead to attracting other molecules or ions, such as oxygen or water. This phenomenon affects the physical and mechanical properties of materials. The physical and mechanical properties increased with sucrose addition. The best composite was prepared using 3% sucrose. This is because sucrose has a crystalline structure that affects the properties of biocomposites. However, the addition of 3% sucrose was not as effective as that of neat PLA. [ABSTRACT FROM AUTHOR]

Cellulosic fibers obtained from Barley straw were utilized to reinforce PHB. Four different processed fibers were employed as reinforcing material: sawdust (SW), defibered (DFBF), delignified (DBF), and bleached (BBF) fibers. The composite was processed from two different perspectives: a discontinuous (bach) and an intensification process (extrusion). Once processed and transformed into final shape specimens, the materials were characterized by mechanical testing (tensile mode), scanning electron microscopy, and theoretical simulations by finite elements analysis (FEA). In terms of mechanical properties, only the elastic moduli (Et) exhibited results ranging from 37% to 170%, depending on the reinforcement composition. Conversely, strengths at break, under both tensile and bending tests, tended to decrease, indicating poor affinity between the components. Due to the mechanical treatment applied on the fiber, DFBF emerged as the most promising filler, with mechanical properties closest to those of neat PHB. DFBF-based composites were subsequently produced through process intensification using a twin-screw extruder, and molded into flowerpots. Mechanical results showed almost identical properties between the discontinuous and intensification processes. The suitability of the material for agriculture flowerpots was demonstrated through finite analysis simulation (FEA), which revealed that the maximum von Mises stresses (5.38 × 105 N/m2) and deformations (0.048 mm) were well below the limits of the composite materials. [ABSTRACT FROM AUTHOR]

Polyethylene (PE), a highly prevalent non‐biodegradable polymer in the field of plastics, presents a waste management issue. To alleviate this issue, bio‐based PE (bio‐PE), derived from renewable resources like corn and sugarcane, offers an environmentally friendly alternative. This review discusses various production methods of bio‐PE, including fermentation, gasification, and catalytic conversion of biomass. Interestingly, the bio‐PE production volumes and market are expanding due to the growing environmental concerns and regulatory pressures. Additionally, the production of PE and bio‐PE biocomposites using agricultural waste as filler materials, highlights the growing demand for sustainable alternatives to conventional plastics. According to previous studies, addition of ≈50% defibrillated corn and abaca fibers into bio‐PE matrix and a compatibilizer, results in the highest Young's modulus of 4.61 and 5.81 GPa, respectively. These biocomposites have potential applications in automotive, building construction, and furniture industries. Moreover, the advancement made in abiotic and biotic degradation of PE and PE biocomposites is elucidated to address their environmental impacts. Finally, the paper concludes with insights into the opportunities, challenges, and future perspectives in the sustainable production and utilization of PE and bio‐PE biocomposites. In summary, production of PE and bio‐PE biocomposites can contribute to a cleaner and sustainable future. [ABSTRACT FROM AUTHOR]

Great environmental and economic benefits can be achieved by utilizing the agricultural residue corn stover (CS) to prepare the biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) composites. However, CS contains polarized hydroxyl groups from its main component cellulose, thus leading to its poor wetting by hydrophobic PBAT. It is of great significance to promote the compatibility between CS and PBAT for the improvement of interfacial interactions and composite performance, but the compatibilizer modified CS/PBAT biocomposites have been rarely mentioned until now. In this study, polyethylene glycol (PEG), glycidyl methacylate (GMA), and ethylene vinyl alcohol copolymer (EVOH) were chosen to investigate the compatibilizer effect on the morphology, microstructure, thermal properties, mechanical strength, and water absorption capacity of the biodegradable CS/PBAT composites. The results reveal that the incorporated compatibilizers obviously improve the interface adhesion between CS and PBAT by reducing the hydrophilicity of CS surface. The enhanced interfacial bonding interactions effectively promote the crystallinity and mechanical strength of the CS/PBAT composites, but the initial degradation temperature and hydrophilicity of compatibilizers themselves also remarkably influence the composites' thermostability and water absorption. Highlights: The agricultural residue corn stover (CS) was used to reinforce PBAT.Effects of three different compatibilizers on the composites were studied.Compatibilizer improves the interface adhesion between CS and PBAT.Compatibilizer promotes crystallinity and mechanical strength of composites.The stability and hydrophilicity of compatibilizer affect those of composite. [ABSTRACT FROM AUTHOR]

Highlights This study explores the utilization of Spent Coffee Grounds (SCG), a residual product of the coffee industry, as a microfiller reinforcement in Poly‐3‐hydroxybutyrate‐co‐3‐hydroxyvalerate (PHBV) biopolymer composites at varying concentrations (1%, 3%, 5%, and 7%). Melt compounding via a twin‐screw extruder and subsequent compression molding were employed in the fabrication process. The SCG microfiller, with particle diameters ranging from 1.11 to 1.28 μm, exhibited a significant negative charge (zeta potential: −20 mV). Hydrophobicity increased up to 5% filler concentration, as indicated by higher water contact angles, but diminished at highest concentration likelihood of agglomeration of the spent coffee grounds within the biopolymer matrix. The addition of SCG enhanced overall mechanical properties, particularly at a 5% filler concentration. Field Emission Scanning Electron Microscopy (FE‐SEM) and Atomic Force Microscopy (AFM) confirmed the successful incorporation of SCG microfiller, improving structural characteristics. Schematic drawings illustrated the interphase bonding of microfiller and matrix. However, properties diminished at the highest filler content (7%) due to coffee grounds' agglomeration. Despite this, SCG incorporation enhanced functional properties, making the biopolymer composite a promising material for sustainable packaging and various applications. Enhancement of properties of spent coffee grounds in PHBV biocomposites. Characterization of Biocomposites for multifunctional properties. Fracture and 2D analysis of the tensile fractured surface of biocomposites. A promising material for sustainable and biodegradable packaging. [ABSTRACT FROM AUTHOR]

Three mutual weight ratios of corn starch powder and polyvinyl acetate PVA wood glue were created for biocomposite materials: 40% starch/60% PVA, 50% starch/50% PVA, and 60% starch/40% PVA. Studying their physical, mechanical, thermal, electrical, and structural characteristics allowed for the evaluation of these composite materials. At room temperature, the samples were manually mixed. The results showed a decrease in the values of the AC conductivity and the thermal conductivity with an increase in the percentage of starch up to 60%, whereas the mechanical properties of the samples that contained starch at a concentration of 60% increased. [ABSTRACT FROM AUTHOR]

The use of wheat middlings (WM) and rice husks (RH) as biofillers for mixing with poly(lactic acid) (PLA) matrix to produce new 3D-printable biocomposites was assessed. Filaments containing 10 and 20 wt.% agro-waste-derived biofillers were manufactured and, for the sake of comparison, filaments of neat PLA were also produced. The obtained filaments were characterized via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), showing potential for further application in additive manufacturing processing. Three-dimensionally printed specimens were thus produced and characterized via: DSC, also evaluating the specific heat capacity (CP) of specific 3D-printed specimens; dynamic mechanical analysis (DMA), also applied for determining the coefficient of linear thermal expansion (CLTE) measured on 3D-printed specimens in two different directions (X and Y); and tensile tests. The latter testing campaign was carried out along three printing directions (X, Y, and Z axes) to test the intrinsic biocomposite features (X-printed samples) as well as interbead and interlayer adhesion (Y- and Z-printed specimens, respectively). All samples demonstrated acceptable properties. The inclusion of a cost-free natural material leads to a strong reduction of the whole material cost. Implementing this new class of composite material to an additive manufacturing technique can significantly reduce the environmental impact of 3D-printed products. [ABSTRACT FROM AUTHOR]

In the context of sustainable materials, this study explores the effects of accelerated weathering testing and bacterial biodegradation on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/rapeseed microfiber biocomposites. Accelerated weathering, simulating outdoor environmental conditions, and bacterial biodegradation, representing natural degradation processes in soil, were employed to investigate the changes in the mechanical, thermal and morphological properties of these materials during its post-production life cycle. Attention was paid to the assessment of the change of structural, mechanical and calorimetric properties of alkali and N-methylmorpholine N-oxide (NMMO)-treated rapeseed microfiber (RS)-reinforced plasticized PHBV composites before and after accelerated weathering. Results revealed that accelerated weathering led to an increase in stiffness, but a reduction in tensile strength and elongation at break, of the investigated PHBV biocomposites. Additionally, during accelerated weathering, the crystallinity of PHBV biocomposites increased, especially in the presence of RS, due to both the hydrolytic degradation of the polymer matrix and the nucleating effect of the filler. It has been observed that an increase in PHBV crystallinity, determined by DSC measurements, correlates with the intensity ratio I1225/1180 obtained from FTIR-ATR data. The treatment of RS microfibers increased the biodegradation capability of the developed PHBV composites, especially in the case of chemically untreated RS. All the developed PHBV composites demonstrated faster biodegradation in comparison to neat PHBV matrix. [ABSTRACT FROM AUTHOR]

In recent decades, interest in oxide nanomaterials with multifunctional properties has grown significantly. Titanium dioxide undoubtedly belongs to them, characterized by exceptional photocatalytic activity, non-toxicity, high availability, biocompatibility, antibacterial properties, and low cost. The treatment of textile materials with TiO2 nanoparticles is relatively simple, but the insufficient bonding efficiency between certain fibers and TiO2 nanoparticles creates a problem regarding the stability and durability of the nanocomposites. In this study, an attempt was made to improve the properties of cotton modified with gelatin hydrogel, which was cross-linked by glutaraldehyde, and incorporated titanium nanoparticles. Three modification methods were applied, varying the mixing regimes of the components and the conditions. The composite materials were investigated via SEM, FTIR, UV-Vis and elemental analysis. For the first time, titanium nanoparticles obtained by the reduction of TiO2 with oxalic acid were used to modify cotton. Cotton samples were modified with gelatin hydrogel cross-linked with glutaraldehyde to increase the active groups of cellulose fibers that bind to Ti ions. Using the hydrogel, the nanoparticles are deposited on the surface of the textile substrate. The elemental analysis shows the presence of TiO2 nanoparticles. Lines for Ti atoms appear, which is evidence that the particles retain their composition after immobilization. Microscopic analyzes showed that TiO2 nanoparticles were distributed unevenly in the cotton matrix. In the UV analysis, the appearance of a new absorption at 890 cm-1 was observed due to the attachment of Ti-NPs. The appearance of the IR peak at 878 cm-1 confirms the formation of chelate complexes of the nanoparticles in the composite material. [ABSTRACT FROM AUTHOR]

Despite the promising potential of bio-composites derived from plant fibers due to their ecological and economic benefits, challenges persist in their preparation, restricting their commercial applications. These challenges are primarily associated with developing suitable methods, acquiring appropriate equipment for treating plant fibers, and addressing the time constraints in preparation. This study aims to contribute to the development and characterization of a new biocomposite and biodegradable material based on natural fibers produced through hot compression. The newly developed biocomposite comprises commercial biodegradable poly-lactic acid (PLA) as a matrix and untreated fiber fabric extracted from date palms as reinforcement. The use of untreated fiber fabric has successfully overcome the preparation difficulties. Experimental results on the new biocomposite reveal the strong adhesion between its fibers and the matrix, emphasizing the significant impact of choosing the right manufacturing conditions on the developed mechanical properties. [ABSTRACT FROM AUTHOR]

This study explores the synthesis and characterization of chitosan/gelatine films incorporating nickel ferrite (NiFe2O4) and cobalt ferrite (CoFe2O4) nanoparticles. The magnetic nanoparticles exhibit superparamagnetic behaviour, making them attractive for various applications, including biomedical uses. The X-ray diffraction analysis confirmed the successful synthesis of NiFe2O4 and CoFe2O4 nanoparticles, and the scanning electron micrographs illustrated well-dispersed ferrite nanoparticles within the biopolymer network, despite the formation of some aggregates attributed to magnetic interactions. Magnetization loops revealed lower saturation magnetization values for the composites, attributed to the chitosan/gelatine coating and the dielectric studies, indicating increased dielectric losses in the presence of ferrites, particularly pronounced in the case of NiFe2O4, suggesting interactions at the interface region between the polymer and ferrite particles. The AC conductivity shows almost linear frequency dependence, associated with proton polarization and conduction processes, more significant at higher temperatures for samples with ferrite particles. [ABSTRACT FROM AUTHOR]

The present work aimed to examine the tensile and flexural behaviors of biocomposites reinforced with continuous plant fibers, utilizing a range of polylactic acid (PLA) matrix materials and varying fiber content. These biocomposites were fabricated using an in situ-impregnated fused filament fabrication (FFF) technique. The study incorporated three different PLA matrix materials, namely PLA, PLA-Matte (PLA-Ma), and PLA-ST, each with distinct mechanical properties. The effect of different linear densities of continuous ramie yarns on the biocomposites was also investigated. The results show that adding continuous ramie yarn significantly enhances both the tensile and flexural strengths, as well as the modulus, of the matrixes. Furthermore, there was a positive correlation between the content of ramie yarn and the increases in strength and modulus. Moreover, the introduction of ramie yarns altered the fracture behavior of the biocomposites, shifting towards brittle fracture. This change significantly impacted the fracture toughness of the matrixes and resulted in a convergence of elongation at the point of breakage. [ABSTRACT FROM AUTHOR]

A novel, promising biocomposite was synthesized through the free radical polymerization method using methyl methacrylate (MMA), acrylic acid (AA), and hydroxyapatite derived from oyster shells (Os‐HA). Fourier transform infrared spectroscopy (FTIR) peaks indicate the conjugation of Os‐HA in the biocomposite. From the TGA analysis, it was observed that a weight loss of nearly 2% is achieved at 210°C, up to 15% at 210 to 420°C, and up to 95% at 420 to 580°C. The SEM image shows the uniform dispersion of the Os‐HA particles and strong interaction with the copolymer matrix. The broad spectrum at 2θ = 14.6° in XRD analysis indicates the amorphous nature of poly(MMA‐co‐AA)/Os‐HA. The higher inhibition zone of the biocomposite is observed at 125 μL against E. coli bacteria. The maximum water absorption is observed at 15 wt% of Os‐HA. The young's modulus gradually increases, while the impact strength decreases up to 20 wt% of Os‐HA. The artificial neural network (ANN) model has been used to assess the optimum values of impact strength, tensile strength, and Young's modulus of the biocomposite material. The correlation factor (R = 0.998) of the ANN model data indicates greater accuracy of the experimental result. [ABSTRACT FROM AUTHOR]

The solid waste generated by the disposal of plastic materials has become one of society's major problems in recent years. In this sense, several researchers have sought alternatives to minimize environmental pollution. A promising option would be using natural materials, biopolymers, or a mixture of these, also known as composites. In this study, composite films were prepared based on babassu mesocarp (BM) and palygorskite clay mineral (Pal), using the casting technique, as well as the plasticizers sodium alginate (SA) and glycerol (Gl). The films obtained were called BM/SA/Gl/Pal, and for comparison were, prepared films containing BM and BM/SA/Gl. The films presented uniform color, smooth and shiny surfaces, and no fissures. FTIR analysis indicated possible interactions between clay and matrix. The SEM analysis showed that the BM film presented more significant surface irregularity. In contrast, the BM/SA/Gl/Pal film gave a more regular topography and excellent thermal stability. Finally, the BM/SA/Gl/Pal film showed more promising results when compared to the others and is considered an attractive material for use in biodegradable packaging. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing concern to counter environmental pollution, and as a result the development of biodegradable materials in various applications has become a major focus. This study aimed to fabricate a biodegradable composite by utilizing discarded hair keratin from beamhouse processing in leather production along with incorporating graphene oxide (GO) to reduce pollution. The composite was prepared using a simple solution mixing method, where the amino functional group of keratin and the carboxyl group of GO were covalently bonded under a redox system. Various analyses, including UV–visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, SEM, biodegradability and oxygen gas transmittance rate, were carried out to evaluate the composite's structure and performance. The results demonstrated that GO was successfully integrated into the keratin matrix, with uniform dispersion of GO observed instead of agglomeration. The composite with the optimum ratio exhibited a 173.98% increase in tensile strength and a 33.52% decrease in elongation as well as improved thermal and biodegradation properties compared to pure keratin. Furthermore, the composite displayed significantly better gas barrier properties (39%) than pure keratin, which can be attributed to the reduction of intermolecular gaps through the composite's strong bonding. Hence, the keratin‐GO composite is a cost‐effective and biodegradable solution to waste materials, with potential use as a packaging material. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In order to solve the problems of dust, low mixing efficiency, and poor quality stability in dry mixing and continuous mixing, this study combined the flocculation extrusion technology with continuous mixing technology of carbon black/additives/natural rubber composites. The flocculation of latex was achieved by carbon black itself and the shearing of the twin screw. The continuous mixing was carried out in a double‐rotor continuous mixer, which was composed of functional elements such as the exhaust section and extrusion section. The results showed that the technology promoted the formation of the filler‐rubber network, the sensitivity of viscosity to temperature was weakened, and the rubber was closer to a Newtonian fluid, with less extrusion swell phenomenon and no obvious spiral distortion. Compared with the dry mixing, the tensile strength, rebound rate, and abrasion resistance of the rubber composites prepared by this technology were increased by 11%, 31%, and 9%, respectively, providing theoretical and technical guidance for the green production and continuous production of high‐performance natural rubber composites. Highlights: The process is achieved by a twin‐screw extruder and a twin‐rotor continuous mixer.The process promotes the formation of the filler‐rubber network.The sensitivity of viscosity to temperature is weakened, with no spiral distortion.The tensile strength, rebound rate, and abrasion resistance are increased by 11%, 31%, and 9%. [ABSTRACT FROM AUTHOR]

Pandanus amaryllifolius fibre (PAF) is an agricultural waste plant derived from the natural cellulosic source of fibre that can be used in various bio-material applications. In the present study, a novel biodegradable thermoplastic cassava starch/beeswax blends reinforced with Pandanus amaryllifolius fibre (TCPS/BW/PAF) bio-composites were successfully developed at varied Pandanus amaryllifolius fibre concentrations of 0, 10, 20, 30, 40, 50 and 60 wt% while beeswax loading was remained constant at 2.5 wt% concentration using hot moulding compression method. A comprehensive characterisation of TCPS/BW/PAF bio-composites was examined in terms of their physical, mechanical, thermal and biodegradation properties. The addition of Pandanus amaryllifolius fibre has significantly improved tensile strength and tensile modulus at maximum value obtained 10.9 and 606.5 MPa, respectively as well as flexural strength and flexural modulus of bio-composite at maximum value obtained 21.37 and 523.76 MPa, respectively until 50 wt% Pandanus amaryllifolius fibre loading. Surface morphology of the fractured tensile samples PAF10 to PAF50 shows compacted structure and fibre breakage, indicating effective stress transfer from starch matrix to PAF during tensile force application. Furthermore, the addition of Pandanus amaryllifolius fibre improved thermal stability from TG, DTG and DSC results; improved crystallinity from XRD analysis; reduced water and moisture affinity from physical properties testing, and lowered the biodegradation rate. Overall, this study shows the potential of TCPS/BW/PAF bio-composites in biopolymer application and bio-packaging industries. [ABSTRACT FROM AUTHOR]

In a blend of poly(lactic acid) (PLA) and thermoplastic starch (TPS), a 15% load of hemp seed lignocellulosic filler (HF) was incorporated. Additionally, separate petrochemical-based compatibilizers, such as dicumyl peroxide (DCM) and benzoyl peroxide (LRL), as well as a bio-based compatibilizer, maleinized hemp seed oil (MHO), were introduced. Adding HF to the PLA/TPS blend reduced tensile mechanical properties due to the stress concentration phenomenon arising from the lack of interaction between components, yielding a more brittle material. This issue was mitigated by adding compatibilizers, notably the incorporation of MHO into the PLA/TPS/HF blend this increased elongation at break by enhancing compatibility among the blend components and providing a plasticizing effect. Moreover, regarding thermal properties, it was observed that the inclusion of HF led to a decrease in the glass transition temperature (Tg), cold crystallization temperature (Tcc), and melting temperature (Tm). Conversely, adding MHO to this blend increased all these values compared to the PLA/TPS/HF mixture, attributed to the plasticizing effect imparted by the modified oil. Additionally, following fracture in Charpy impact testing, the samples were subjected to field emission scanning electron microscopy (FESEM) analysis to examine the fractured surface of the various samples.

Abstract Natural fibers are one of the most attractive materials in biocomposites due to their potential for sustainability. This study aims to prepare sustainable composite materials using fibers from Sansevieria trifasciata (snake plant) and to investigate their mechanical, morphological, and water absorption properties. The composite was prepared with epoxy resin through a manual hand lay‐up process, maintaining standard parameters with changeable reinforcement (10%, 20%, and 30%). The mechanical properties (tensile, impact, and flexural strength), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and water absorbency of the composites were evaluated. The result showed that the tensile strength, flexural strength, and impact resistance of the composites are 6.99 MPa, 10.77 MPa, and 14 J, respectively, for 30% fiber components, which are significantly higher than other composite materials. The SEM analysis showed a strong interfacial bond between the snake plant fiber and the epoxy resin. The FTIR analysis revealed a reduction in hemicellulose and lignin and an improvement in the interfacial adhesion between snake plant fiber and epoxy resin. The composites also demonstrated time‐dependent increases in water absorption, with the sample containing 30% fiber components showing the best absorbency performance at 0.88%. Highlights A study is being conducted on the effective and sustainable use of biowaste. The composite materials loaded with 30% fibers had significantly high tensile strength, flexural strength, and impact resistance. The SEM analysis of snake plant fiber‐reinforced polymer composite showed a strong interfacial bond between fiber and epoxy resin. The FTIR analysis of the composite revealed the reduction of hemicellulose and lignin. The use of non‐renewable materials is reduced, and eco‐friendliness is promoted.

Graphene nanoplatelets (GNP) were incorporated into thermoplastic starch (TPS) films, and effects on water absorption and mechanical properties were investigated. GNP inclusion formed a barrier that significantly reduced water absorption, resulting in denser TPS/GNP films. Fourier-transform infrared spectroscopy (FTIR) revealed changes in chemical interactions, and FESEM analysis showed improved GNP dispersion at this concentration. Water contact angle results indicated increased hydrophobicity with higher GNP content. Positive influences on mechanical properties, such as tensile strength and Young's modulus, were observed at 12 wt% GNP, but excessive GNP content caused agglomeration and reduced ductility. The study results highlight the potential of GNP-reinforced TPS films for improved water resistance and mechanical properties, emphasizing the need for careful optimization in future research.

An environmental pollution problem is caused in part by packaging materials made from non-biodegradable synthetic polymers derived from petroleum. In this study, eco-friendly biofoams derived from natural rubber (NR) latex and rice starch (RS) were manufactured on a laboratory scale using the Dunlop process. Rice starch content was varied from 0 to 50 phr. The morphological, thermal, physical, mechanical, and biodegradability properties of the NR/RS biocomposite foams were characterized. Scanning electron microscopy (SEM) was used to assess the morphology of the foam cells. Dynamic mechanical thermal analysis (DMTA) and Thermogravimetric analysis (TGA) were used to investigate the thermal characteristics. When RS was present, it was discovered that the biocomposite foams had decreased thermal stability and enhanced biodegradability. Introducing RS into the NR/RS biocomposite foams also decreased tensile strength, elongation at break, and rebound resilience but increased the 100% modulus, hardness, compression force deflection (CFD), and compression set. The NR/RS biocomposite foams better preserved the banana fruit than the absence of foam, with lower ethylene accumulation, lower total soluble solids (TSS), higher pulp firmness, and good color preservation. This demonstrated that these NR/RS biocomposite foams helped to preserve banana fruit quality during storage and could be used in sustainable packaging applications.

Abstract The application of continuous natural fibers as reinforcement in composite thin-walled structures offers a feasible approach to achieve light weight and high strength while remaining environmentally friendly. In addition, additive manufacturing technology provides a favorable process foundation for its realization. In this study, the printability and energy absorption properties of 3D printed continuous fiber reinforced thin-walled structures with different configurations were investigated. The results suggested that a low printing speed and a proper layer thickness would mitigate the printing defects within the structures. The printing geometry accuracy of the structures could be further improved by rounding the sharp corners with appropriate radii. This study successfully fabricated structures with various configurations characterized by high geometric accuracy through printing parameters optimization and path smoothing. Moreover, the compressive property and energy absorption characteristics of the structures under quasi-static axial compression were evaluated and compared. It was found that all studied thin-walled structures exhibited progressive folding deformation patterns during compression. In particular, energy absorption process was achieved through the combined damage modes of plastic deformation, fiber pullout and delamination. Furthermore, the comparison results showed that the hexagonal structure exhibited the best energy absorption performance. The study revealed the structure-mechanical property relationship of 3D printed continuous fiber reinforced composite thin-walled structures through the analysis of multiscale failure characteristics and load response, which is valuable for broadening their applications.

Bio-based materials are becoming increasingly important as demand for conventional wood-based products raises environmental issues, potentially leading to deforestation. As a result, environmentally acceptable, cost-effective, and easily available alternative natural biomass materials for these intended utilizes are highly required. In this work, a waste wheat straw cellulose polymer matrix composite reinforced with sisal fiber through physical and chemical treatment methods for fiberboard application was synthesized and characterized. The composite materials were developed using the polymer solution casting method. Waste wheat straw composites with 0, 5, 10, 15, 20, 25, and 30 wt% of sisal fiber with respect to the matrix were prepared. Qualitative and quantitative approaches, as well as exploratory and experimental research methods, were employed. Fourier transform infrared (FTIR) spectroscopy was used to investigate the functional group of wheat straw cellulose, while scanning electron microscopy (SEM) was used to examine the sisal fiber morphology. Flexural strength was tested by using a universal testing machine, and impact strengths were measured by a V-notch Charpy tester based on medium-density fiberboard (MDF) and low-density fiberboard (LDF) as control samples. The water absorption of the samples was also studied. The work complied with ANSI A208.2–2002's general test standards for general usage. The results showed that the maximum flexural strength attained at 20 wt% of reinforcement was (56.83 MPa) and the impact strength at 20 wt% sisal fiber was (30.33 J), while the MDF and LDF control samples' flexural strengths were 35.5 MPa and 41.5 MPa, respectively, and the impact strengths were (20.16 J and 25 J), respectively. The lowest water absorption value was achieved at 5 wt% of sisal fiber, and the value was (2.09%). However, water absorption of (74.04%) for MDF and (106.98%) for LDF was measured. Thus, it was discovered that using waste biomass such as wheat straw instead of raw wood may provide a composite material with superior flexural strength, impact strength, and reduced water absorption for fiberboard applications. [ABSTRACT FROM AUTHOR]

This study describes a novel spray-on mulch material as an alternative to currently used weed control methods. The mulch material is based on renewable raw materials, mainly rapeseed oil, starch and sodium alginate. Laboratory tests were conducted to obtain a mulch material with the best possible properties. Formulations with different ingredients were prepared and tested for their material properties. The formulations were investigated for potential shrinkage tendency and heat resistance as well as water resistance. Further tests such as resistance to mould infestation and aerobic degradability according to DIN EN ISO 17556 were carried out with the formulation that performed best in the previous tests. Mould resistance was enhanced by adding sodium benzoate. In the laboratory experiment, the CO2 decomposition rate was about 30% after seven weeks. With the favouritised variant, which was found step by step through the experiments, an outdoor field test was carried out to investigate the durability under natural conditions over the vegetation period. In the field, the mulch material maintained its function for six months. In the greenhouse, the effect of the mulch material on weeds was studied. It was found that the mulch material showed a high efficiency in controlling above-ground biomass of Elymus repens, Amaranthus retroflexus, and Setaria viridis. In addition, the biomass of the roots of Amaranthus retroflexus and Elymus repens was reduced. Further studies are on the way to elucidate field suitability and the weed suppressive effect under different environmental conditions. [ABSTRACT FROM AUTHOR]

This research explores the innovative fabrication and characterization of recycled polypropylene composites that reinforced by natural fibers, specifically date palm micro fibers (DPF). Employed a twin-screw extruder for the mixing, and injection molding technique for the samples fabrication. DPF was incorporated at varying weight percentages (0, 2, 5, and 10 wt%). A comprehensive analysis, including thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), was conducted to assess thermal stability, chemical interactions and crystalline structure. Mechanical properties were evaluated through shore-D hardness and uniaxial tensile tests. Notably, the study revealed that an increased DPF filler content resulted in superior mechanical properties, such as enhanced shore-D hardness and tensile strength. This improvement was attributed to the alignment of DPF fillers and the recycled polypropylene matrix. The significance of this research lies in showcasing the promising potential of DPF as an eco-friendly reinforcement material in recycled polypropylene biocomposites, providing a sustainable and environmentally friendly alternative for various engineering applications. The work contributes to advancing greener solutions in material science and highlights the unique advantages of DPF in enhancing composite materials.

Despite the promising potential of bio-composites derived from plant fibers due to their ecological and economic benefits, challenges persist in their preparation, restricting their commercial applications. These challenges are primarily associated with developing suitable methods, acquiring appropriate equipment for treating plant fibers, and addressing the time constraints in preparation. This study aims to contribute to the development and characterization of a new biocomposite and biodegradable material based on natural fibers produced through hot compression. The newly developed biocomposite comprises commercial biodegradable poly-lactic acid (PLA) as a matrix and untreated fiber fabric extracted from date palms as reinforcement. The use of untreated fiber fabric has successfully overcome the preparation difficulties. Experimental results on the new biocomposite reveal the strong adhesion between its fibers and the matrix, emphasizing the significant impact of choosing the right manufacturing conditions on the developed mechanical properties.

Since the last two decades, the use of natural fiber reinforced polymer composites has garnered significant application considerations over the synthetic fiber reinforced composites due to their numerous advantages and unique properties. Likewise, epoxy resin has attracted the interest of many researchers for composite synthesis, basically because of its chemical stability, thermal and mechanical characteristics. Hence, the primary aim of this study was to investigate the influence of dombeya fiber and paper particulate on the physical and mechanical properties of dombeya fiber and paper particulate-reinforced polymer composites for structural applications. Dombeya fiber and paper particles are renewable and biodegradable materials, thereby making them environmentally friendly materials to replace synthetic materials. Hand lay-up technique was utilized to fabricate the hybrid-reinforced biocomposites after which they were subjected to mechanical, wear, density, and moisture absorption properties. The surface morphology of the fractured surface was also analyzed to investigate its microstructural features. It was discovered from the results that hybrid biocomposites demonstrated improved properties over the unreinforced composite, with composites from 9-wt% dombeya fiber-paper particles reinforced biocomposite exhibiting the most suitable properties with commensurate density with the unreinforced epoxy matrix. These obtained characteristics support the material as a suitable material for biomedical apparatus application such as orthopedic implants, surgical instruments, and bone fixation devices.

The low carbon footprint, biodegradability, interesting mechanical properties, and relatively low price are considered some of the reasons for the increased interest in polylactic acid-based (PLA-based) filaments supplied with natural fillers. However, it is essential to recognize that incorporating natural fillers into virgin PLA significantly impacts the printability of the resulting blends. The complex inter-relationship between process, structure, and properties in the context of fused deposition modeling (FDM)-manufactured biocomposites is still not fully understood, which thus often results in decreased reliability of this technology in the context of biocomposites, decreased accuracy, and the increased presence of defects in the manufactured biocomposite samples. In light of these considerations, this study aims to identify the optimal processing parameters for the FDM manufacturing process involving wood-filled PLA biocomposites. This study presents an optimization approach consisting of Grey Relational Analysis in conjunction with the Taguchi orthogonal array. The optimization process has identified the combination of a scanning speed of 70 mm/s, a layer height of 0.1 mm, and a printing temperature of 220 °C as the most optimal, resulting in the highly satisfactory combination of good dimensional accuracy (Dx = 20.115 mm, Dy = 20.556 mm, and Dz = 20.220 mm) and low presence of voids (1.673%). The experimentally determined Grey Relational Grade of the specimen manufactured with the optimized set of process parameters (0.782) was in good agreement with the predicted value (0. 754), substantiating the validity of the optimization process. Additionally, the research compared the efficacy of optimization between the integrated multiparametric method and the conventional monoparametric strategy. The multiparametric method, which combines Grey Relational Analysis with the Taguchi orthogonal array, exhibited superior performance. Although the monoparametric optimization strategy yielded specimens with favorable values for the targeted properties, the analysis of the remaining characteristics uncovered unsatisfactory results. This highlights the potential drawbacks of relying on a singular optimization approach. [ABSTRACT FROM AUTHOR]

The main advantage of green composites is their biodegradability, but this biodegradability can also be considered a drawback if the degradation appears during the service life of the component. Therefore, the study of the mechanical behavior of green composites after hygrothermal aging tests is necessary to analyze their degradation process. This study aims to comprehensively analyze the hygrothermal aging behavior and aging mechanism of flax-fiber-reinforced polylactic acid (PLA) biocomposites. The fully biodegradable composites are manufactured by compression molding. In addition, the influence of atmospheric-pressure plasma treatment on the mechanical properties of the biocomposite is studied. Specimens are exposed to water vapor and 40 °C environmental conditions in a stove for up to 42 days. Several specimens of each type are taken out at regular intervals and tested to examine the water absorption, mechanical properties, and thermal characterization. The results show that the stiffness was significantly reduced after 24 h due to matrix degradation, while the strength was reduced only after three weeks. [ABSTRACT FROM AUTHOR]

In this investigation, the examination revolves around the characterization of diatomite-enhanced modified safflower oil (MSO)-derived polyester biocomposites. The primary objective is to explore the feasibility of these biocomposites as a substitute for petrochemical-based unsaturated polyester (UP) materials, with the overarching goal of enhancing their economic sustainability. Experimental data analysis employed Response Surface Methodology (RSM) and Artificial Neural Network (ANN), uncovering the optimal composition for the polyester biocomposite to be 6.7 wt.% MSO and 4.5 wt.% diatomite. During the RSM analysis, it was noted that the response parameters exhibited quadratic p -values, specifically, for density (p <.0001), thermal conductivity (p <.0001), and Shore D hardness (p <.0003). However, higher ratios of MSO lead to decreased hardness and increased curing time. SEM images reveal a detrimental impact on the surface morphology of the polyester biocomposite when the diatomite content reaches 8 wt.%. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) offer valuable insights into the chemical bond structure and thermal behavior of the biocomposite, respectively. The Cure Index (CI) value for the diatomite-enhanced composite was determined to be 0.925, indicating a favorable contribution to the polyester curing process. The study finds that diatomite contributes to a linear change in the thermal conductivity coefficient, making the biocomposite suitable for use in the insulation industry. Overall, the study suggests that diatomite reinforced MSO-based polyester biocomposites have the potential as an alternative to petrochemical unsaturated polyester. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biobased and biodegradable polymer. This polymer is considered promising, but it is also rather expensive. The objective of this study was to compound PHBV with three different organic fillers considered waste: human hair waste (HHW), sawdust (SD) and chitin from shrimp shells. Thus, the cost of the biopolymer is reduced, and, at the same time, waste materials are valorised into something useful. The composites prepared were characterised by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile strength and scanning electron micrograph (SEM). Tests showed that chitin and HHW did not have a reinforcing effect on tensile strength while the SD increased the tensile strength at break to a certain degree. The biodegradation of the different composites was evaluated by a soil burial test for five months. The gravimetric test showed that neat PHBV was moderately degraded (about 5% weight loss) while reinforcing the polymer with organic waste clearly improved the biodegradation. The strongest biodegradation was achieved when the biopolymer was compounded with HHW (35% weight loss). The strong biodegradation of HHW was further demonstrated by characterisation by Fourier-transform infrared spectroscopy (FTIR) and solid-state nuclear magnetic resonance (NMR). Characterisation by SEM showed that the surfaces of the biodegraded samples were eroded. [ABSTRACT FROM AUTHOR]

In this work, a thermal behaviour comparison of a new bamboo-based and banana-based Green Bio-Composites (GBC) is conducted using thermogravimetric analysis (TGA) and cone-calorimeter experiments. An Intumescent Fire-Retardant (IFR) coating (a mixture of Exolit IFR36 and boric acid) has been applied on the investigated GBC materials in order to explore the flammability resistance of such GBCs. Vacuum Bag Resin Transfer Moulding (VBRTM) technique has been used to manufacture the samples. TGA test have been conducted under oxidative atmosphere with three different heating rates while cone calorimeter tests have been performed with a horizontally exposure on the top surface of the sample. The outcomes of TGA revealed that Bamboo-based (BM-GBC) and Banana-based (Bn-GBC) materials exhibited similar thermal degradation patterns. However, BM-GBC outperformed Bn-based in the cone calorimetry analysis, this is proven by the fire reaction parameters as well as the higher char residue. In addition, IFR coating improved the flame retardancy of both GBCs, reduced the Peak Heat Release Rate (PHRR) by approximately 40–50% and smoke production (SEA) by 26%. SEM and EDS analysis of char residue were performed to deeply investigate the effectiveness of the IFR as a protecting layer. [ABSTRACT FROM AUTHOR]

Currently, there is a notable attraction within the industry towards biocomposites, driven by the increasing fascination with natural fiber-reinforced composites (NFRCs). These NFRCs offer remarkable benefits, including cost-effectiveness, biodegradability, eco-friendliness, and favorable mechanical properties. As a result, the manufacturing processes of natural fiber reinforced polymer (NFRP) composites have garnered attention from both industrial professionals and scientists. The emergence of these eco-friendly materials in the automotive and aerospace industries has sparked interest in understanding their production techniques. However, the machining processes of NFRP composites pose significant challenges due to the complex structure of natural fibers, necessitating thorough studies to address these issues effectively. This research paper presents a comprehensive investigation on surface roughness during the milling process of Alfa/epoxy biocomposites. A set of 100 experimental trials was conducted to test the surface roughness, and analysis of variance (ANOVA) was used to assess the impact of cutting parameters and chemical treatment on surface quality. To develop a predictive model for surface roughness, a hybrid approach called ANN-GA (artificial neural networks-genetic algorithms) is proposed in this research. This approach combines ANN and GA to determine an optimal neural network architecture. The performance of the ANN-GA model is compared to the Levenberg–Marquardt backpropagation (LM) algorithm. ANOVA results show that the feed per revolution have a significant influence on surface roughness, followed by the chemical treatment of fibers, while machining direction has a smaller effect. The ANN-GA model demonstrates good accuracy in surface roughness prediction compared to the LM algorithm. [ABSTRACT FROM AUTHOR]

Graphene nanoplatelets (GNP) were incorporated into thermoplastic starch (TPS) films, and effects on water absorption and mechanical properties were investigated. GNP inclusion formed a barrier that significantly reduced water absorption, resulting in denser TPS/GNP films. Fourier-transform infrared spectroscopy (FTIR) revealed changes in chemical interactions, and FESEM analysis showed improved GNP dispersion at this concentration. Water contact angle results indicated increased hydrophobicity with higher GNP content. Positive influences on mechanical properties, such as tensile strength and Young's modulus, were observed at 12 wt% GNP, but excessive GNP content caused agglomeration and reduced ductility. The study results highlight the potential of GNP-reinforced TPS films for improved water resistance and mechanical properties, emphasizing the need for careful optimization in future research. [ABSTRACT FROM AUTHOR]

The fiber-filled polymer composite is one of the best materials which provides a symmetrical superior strength and stiffness to structures. With the strengthening of people's environmental protection and resource reuse consciousness, the development of renewable materials, especially natural fiber-filled polymer composites, is receiving great attention. This study investigated the mechanical properties of polymer composites incorporating waste materials from the food processing industry and agricultural sources. Waste vegetal fiber-filled polymer biocomposites (WVFFPBs) with varying fiber types and 3D printing orientations were systematically fabricated. Subsequently, the tensile tests were executed to comprehensively assess the anisotropic mechanical behaviors of the WVFFPBs. The results demonstrated that WVFFPBs performed excellent anisotropic mechanical properties compared to pristine matrix samples as print orientation changed. As the printing angle increased from 0° to 90°, the tensile mechanical properties of the WVFFPBs displayed a decreasing trend. Moreover, the print orientation–anisotropic mechanical behavior relationship of 3D-printed WVFFPBs was revealed through the analysis of the material manufacturing characteristics and damage features. [ABSTRACT FROM AUTHOR]