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In this study, Washingtonia fibres (AW) and Kenaf fibres (KF) were utilized as environmentally friendly fillers to improve the quality of the resin matrix. The mechanical, morphological, and physical properties of the WA/KF biocomposites were assessed throughout this research. The mechanical tests (tensile strength and moduli, elongation at break, flexural strength along with moduli, and the impact properties) were carried out. The hybrid biocomposites (3AW/7KF) exhibited the highest tensile strength (16.05 MPa) and modulus (4.6 GPa) among pure and other hybrid biocomposites. The impact strength and resistance of hybrid biocomposites (1AW/1KF and 7AW/3KF) showed the highest impact strength (1694 J/m 2 ) while the 3AW/7KF hybrid biocomposite, the impact strength value was 1630 J/m 2 (17.2 J/m). SEM images indicated good distribution and bonding of hybrid biocomposites. The investigation using morphological tests (Scanning Electron Microscopy (SEM)) displays the longitudinal roughness on the surface, which acts as a very significant function in the adhesion between the AW/KF fibres and the resin. Furthermore, the results of SEM confirm better bonding in the biocomposites, fibre fracture, pull-out, fibre shearing, and tearing in the pure and hybrid composites. From the water absorption test, it was observed that, when increasing the immersion time of biocomposites, the WA percentage of KF biocomposite significantly increased (37%) compared to other biocomposites. However, the hybrid and pure biocomposites exhibited more resistance to increase the WA percentage after increasing the immersion times, compared to other biocomposites. Furthermore, the thickness swelling (TS) of hybrid biocomposites increased compared to pure biocomposites. The biocomposite sample (3AW/7KF) was thicker on the 7th day exhibiting the greatest increases in thickness swelling (4.98%) while the hybrid biocomposite exhibited greater WA value compared to other correspondence samples. Finally, the KF and AW hybrid blends can be appropriate for several applications, for example, textiles, machinery part production industries, medicine, and automobiles, and construction, specifically buildings, bridges, and structures such as boat hulls, swimming pool panels, racing car bodies, shower stalls, bathtubs, storage tanks. Overall, the findings exhibit that the hybridisation of natural fibres (KF/AW) is a sustainable approach for obtaining biocomposites with advanced mechanical and thermal performance. Hence, they could be used in numerous specific applications, including automobile panels, structural products, sporting goods and furniture tools., (© 2024. The Author(s).)

Context: Pink colored acrylic does not always satisfactorily replicate the natural gingival color, especially in individuals with pigmented mucosa. In such situation clear acrylic denture base material can be used. Hence, there is a need of a comparative study of the mechanical properties of the clear and pink colored denture base resins., Aims: The aim of this study is to compare the mechanical properties, i.e., tensile, flexural, compressive, and impact strength (IS) of clear and pink colored denture base resins., Settings and Design: This was comparative in vitro study., Materials and Methods: A total of 80 specimens were divided into two groups of 40 specimens each of clear and pink colored acrylic resin. Specimens for testing flexural, tensile, compressive, and ISs of acrylic resin (10 in each group) were divided. A universal testing machine was used for measuring flexural, tensile, and compressive strength (CS) while the Izod/Charpy impact tester was used for IS., Results: The mean tensile strength for clear resin (n = 10) was 30.90 ± 1.663 MPa and that for pink resin (n = 10) was 31.30 ± 8.166 MPa. The mean residual flexural strength for clear resin (n = 10) was 75.60 ± 17.212 MPa, whereas for pink resin (n = 10) was 76.10 ± 14.130 MPa. The mean CS for clear resin (n = 10) was 84.60 ± 2.503 MPa and for pink resin (n = 10) was 85.40 ± 16.222 MPa. The mean IS for clear resin (n = 10) was 11.50 ± 5.104 MPa. While for pink resin (n = 10) was 11.90 ± 1.370 MPa., Conclusions: The results show that clear acrylic resin denture base material has mechanical properties similar to that of pink acrylic resin denture base material., Competing Interests: None

Expanded polystyrene (EPS) waste also known as Styrofoam is a common material found in packaging and insulation applications and presents significant environmental challenges due to its nonbiodegradable nature. To address this issue, researchers have explored EPS waste as a potential polymer matrix for developing composite materials. Many researchers have studied the physical, mechanical, and thermal behavior of EPS‐based materials. Therefore, this review provides the current state of knowledge regarding the physical, thermal, and mechanical properties of EPS‐based composites. The effect of reinforcement content, filler size, EPS content, processing method, and other factors that affect the properties of EPS‐based composites is covered in this review. The physical properties examined include density, porosity, and water absorption properties, while the mechanical behavior encompasses tensile strength, impact strength, and flexural resistance of EPS waste–based materials. This review also identifies key findings from various studies and discusses the influence of EPS waste on the overall performance of the composites. Moreover, it highlights the challenges and opportunities associated with utilizing EPS waste in composite materials, along with potential avenues for future research. Overall, this review serves as a valuable resource for researchers, engineers, and stakeholders interested in understanding the physical, thermal, and mechanical properties of EPS waste–based composites and their potential applications in sustainable material development, thereby enhancing the commercial value of recycled materials. [ABSTRACT FROM AUTHOR]

Duplex stainless steels provide a desirable combination of corrosion resistance, strength and toughness. Additive manufacturing of duplex stainless steels can be challenging due to high cooling rates and repeated reheating, which can produce detrimental microstructural constituents. In this study, a coaxial directed energy deposition system with laser and wire was used to deposit 2205, 2209 and 2509 duplex stainless steels. Corrosion resistance, strength and impact toughness in both as-built and solution annealed condition was tested and the microstructure was characterized. Solution annealing improved impact toughness considerably, produced a slight increase in corrosion resistance and a slight decrease in tensile strength. The 2205 material surpassed all common requirements and exhibited better corrosion resistance than 2209 due to less segregation between austenite and ferrite. Segregation of alloying elements was lower in intragranular austenite than grain boundary allotriomorph and Widmanstätten austenite. The 2209 and 2509 materials provided relatively low strength, especially in the solution annealed condition. For the 2509 material, sigma phase caused low as-built corrosion resistance and impact toughness. Overmatching welding consumables were found to be less suitable as feedstock for additive manufacturing due to high austenite content in the deposited material and lower corrosion resistance than conventional duplex compositions. [ABSTRACT FROM AUTHOR]

Highlights The present work investigates effect of the incorporation of GNPs into epoxy matrix composites reinforced with CFs on their electrical, mechanical and viscoelastic properties. The GNP content in the composite were added as 0.1%, 0.2%, 0.3%, and 0.4% by weight. The study presents detailed analysis of conductivity mechanism revealing an 8‐fold increase in surface electrical conductivity at 0.4 wt% GNP content, reaching 2.32 S/m. The mechanical properties showed significant enhancement with the incorporation of GNPs up to 0.3 wt%, reaching a maximum tensile strength of 1008 MPa and peak flexural strength of 952 MPa, and the highest impact strength of 13 J/cm2. However, a decline in mechanical performance was observed at 0.4 wt% GNP content, primarily due to fiber‐matrix debonding. The DMA analysis further revealed an increase in the storage modulus and loss modulus at 0.1 wt% GNP content, reaching 10,099 and 1570 MPa, respectively. However, at higher GNP content, adverse effects on the composite's behavior were observed, attributed to uneven distribution and interactions of the GNPs. Impact of GNPs on the electrical and viscoelastic properties of CFRP analyzed. GNPs enhance surface electrical conductivity of CFRP composites at 0.4 wt%. GNPs improve viscoelastic properties of CFRP composites at 0.1 wt%. Suitable mechanisms illustrated, correlated with results and discussed. [ABSTRACT FROM AUTHOR]

Highlights Basalt fiber (BF)‐reinforced thermoplastic composites are not only made with little environmental pollution and recyclable, with obvious environmental value, but also have excellent mechanical properties, excellent resistance to high temperature and corrosion. In the present study, modifications to the interface of BF were performed using monoaminosilane and diaminosilane agents, specifically 3‐aminopropyltrimethoxysilane (SATMS) and N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane (DATMS), along with a urea‐modified silane, 3‐urethylpropyltrimethoxysilane (SUTMS). These modifications were evaluated against one another. Utilizing a film lamination technique, composites of BF and thermoplastic polypropylene resin (BF‐PP) were fabricated. Analytical assessments included examining the modified fibers' surface morphology, chemical structure, and roughness. Mechanical assessments of the modified BF‐PP composites were conducted, revealing that composites treated with the urea‐inclusive silane agent (BF/SUTMS‐PP) exhibited superior performance, enhancing flexural strength by 26%, tensile strength by 22.4%, and notched Izod impact strength by 21%. However, because of the lower thermal stability of SUTMS, when the processing temperature exceeds 240°C, there is a decomposition of the heated Y‐base end, thus affecting the mechanical properties of BF/SUTMS‐PP. The basalt fibers were modified by SATMS, DATMS, and SUTMS. The urea‐containing silane coupling agent has the strongest enhancement effect. Composite reinforced with SUTMS‐BF displayed the best mechanical properties. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the mechanical properties and degree of conversion of a novel 3D-printing model resin and compare it to eight commercially available model resins. An experimental resin formulated by our proprietary resin technology along with DentaModel, NextDent 2, KeyModel Ultra, Rodin Model, Die and Model 2, DMR III, LCD Grey, and Grey Resin were used in this study. Parallelepiped specimens (2 × 2 × 25 mm, n = 5) were printed and measured for their flexural strength (FS), flexural modulus (FM), and modulus of resilience (MR) in accordance with ISO-4049. Dumbbell-shaped specimens (Type V, n = 5) were printed to test tensile strength (TS) and elongation according to ASTM-D638. Barcol hardness (BH) was measured based on ASTM D2583 using broken tensile strength specimens. Izod-type test specimens (3.2 × 12.7 × 63.5 mm, n = 10) were printed, notched, and determined for impact strength according to ASTM D256-10. The degree of conversion was measured using FTIR (n = 5). Data were analyzed using one-way ANOVA and post hoc Tukey tests (p ≤ 0.05). The experimental resin exhibited a similar or significantly greater flexural strength (88.8 MPa), modulus of resilience (2.13 MPa), tensile strength (54.4 MPa), and hardness (82.9) than most model resins (FS 62.6–90.1 MPa, MR 1.37–2.0 MPa, TS 36.3–54.6 MPa, BH 66.1–83.7). The elongation (6.2%) and impact strength (14.2 J/m) of the experimental resin are statistically the same as those of most resins (3.0–7.5%, 13.8–16.4 J/m). However, the experimental resin has a significantly lower flexural modulus (1.97 GPa) than most resins (2.18–3.03 GPa). The experimental resin exhibited a significantly higher degree of conversion (66.58%) than most resins (1.11–62.34%) for 40 s of light curing; however, a similar or higher value (84.87%) than most resins (72.27–82.51%) was obtained for 3D-printed objects. The newly formulated 3D-printing model resin exhibited adequate mechanical properties and degree of conversion, which is comparable to the commercially available 3D-printing model resin materials. The new 3D-printing model resin can be used for modeling applications in restoration, orthodontics, implants, and other cases. [ABSTRACT FROM AUTHOR]

The influence of the addition of ground buckwheat hulls on the properties of biocomposite on the basis of 3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) is presented here. The changes in the material after repeated reprocessing—up to five recycling cycles—are written in the paper. Analysis of the shrinkage, water adsorption, selected mechanical properties, tensile impact strength, hardness and the microstructure of the surface layer was performed. The results show that the application of the buckwheat hulls into the biopolymer decreases the material shrinkage. It improves the material dimensional stability, as well as increases the water adsorption in the wake of the hydrophobic properties of the filler. The addition of the natural filler also leads to an increase in composite stiffness. The decrease in the tensile impact strength and the elongation at break is also noted. The reprocessing of the biocomposite initially led to a decrease in its mechanical properties, but the results stabilized after further processing cycles. This indicates the improvement of the microstructure homogeneity. The microscopic analysis shows that buckwheat hull particles were better embedded in the matrix after recycling. The increase in hardness was also noted. The PHBV–ground buckwheat hull biocomposite is characterized by stable mechanical properties and by recycling resistance, which makes it a promising material in terms of the sustainable development. [ABSTRACT FROM AUTHOR]

Highlights In this study, a series of sustainable eco‐friendly epoxy resin (EP)‐based biomass composites (DSA‐CS/EP) were prepared using bisphenol A EP as matrix, 2‐methylimidazole as curing agent, and corn stalk (CS) esterified with dodecene succinic anhydride (DSA) as filler. The static contact angle test results showed that the hydrophobicity of CS after esterification with DSA (DSA‐CS) was enhanced, which results in the compatibility of DSA‐CS with EP matrix was improved. And then, the DSA‐CSs were dispersed homogeneously in the matrix without agglomerating. The morphology and properties of the biomass composites were studied and analyzed in order to elucidate the toughening mechanism of CS and DSA‐CS. When the content of DSA‐CS is 15 wt%, the tensile strength and impact strength of DSA‐CS/EP reached a maximum value of 30.39 MPa and 3.34 KJ/m2, which were increased by 128.49% and 81.52% compared with pure EP. Finally, it is deduced that the possible toughening mechanism is that DSA‐CS can not only share part of the external stress but also a mutual solute region is formed between DSA‐CS and EP matrix. Corn stalks esterified by DSA were used as reinforcement filler for epoxy resin. The cellulose in CS was mainly esterified. The tensile and impact strength of DSA‐CS 15/EP reached a maximum value. A mutual solute region is formed between filler and matrix. [ABSTRACT FROM AUTHOR]

Highlights Fiberglass‐reinforced composites are extensively utilized in a diverse range of fields. Nonetheless, relying on the high shear forces generated during twin screw extruder processing to enhance the dispersion and distribution of glass fibers (GFs) can result in GF breakage and the degradation of the molecular chains of polyamide (PA). Consequently, this leads to a diminished performance of the composite material. In this study, high‐performance PA6/GF composites were effectively fabricated through the utilization of a dual‐speed non‐twin screw extruder operating within a chaotic field. Furthermore, optimization was achieved by substituting the kneading block (KB) with a perturbation ring element (PRE). In this paper, a comparative analysis was conducted between the flow fields and experimental results obtained from varying thread arrangements. The result indicates that, in comparison to KB with discontinuous structures and sudden geometric shapes, PRE elements possessing open structure in both the transverse and longitudinal directions effectively mitigated the shear effect and residence time during processing. This led to the significant enhancement of the residual length of the GF, molecular weight of PA6, heat distortion resistance and thermal stability of the composites. Additionally, enhanced performance was observed in PA6/GF composites prepared using the PRE configuration. Specifically, PA6/GF composites prepared by PRE S3 configuration showed outstanding impact strength of 13.3 kJ/m2 and a tensile strength of 151.6 MPa, representing respective increases of 15.7% and 6.9% compared with those prepared using the twin screw extruder (TSE). This work introduced an innovative device and molding technique for the production of high‐performance fiber‐reinforced polymer composites. High‐performance PA/GF was successfully manufactured by non‐twin screw extruder. The modified non‐twin screw leaded to better dispersion and distribution of GF. The damage of fiberglass and the degradation of PA were significantly reduced. The mechanical properties were significantly improved without using additives. The heat distortion resistance and thermal stability of PA/GF were improved. [ABSTRACT FROM AUTHOR]

Wood flour (WF) at 10 wt.% and 20 wt.% loadings was used as a reinforcing filler to enhance the applicability of polypropylene (PP) for 3D printing. After performing printability tests of PP wood plastic composites (WPCs), the mechanical properties of both injection‐molded and 3D‐printed PP WPC specimens were explored. Test specimens were prepared from 3D printed hexagons for analyzing the mechanical properties. Adding WF to neat PP increased the storage modulus and the glass transition temperature while decreasing the degree of crystallinity and the coefficient of thermal expansion, while enhancing the printability of neat PP. The tensile strength, tensile modulus of elasticity, flexural strength, and flexural modulus of elasticity of injection‐molded neat PP improved by up to 21%, 59%, 30%, and 56%, respectively, with 20 wt.% WF. However, the impact strength of injection‐molded neat PP decreased by 85%, with 20 wt.% WF. After 3D printing, the tensile strength and tensile modulus of elasticity of printed neat PP increased by up to 84% and 60%, respectively, with 20 wt.% WF. The flexural strength and flexural modulus of elasticity of neat printed PP remained unchanged compared to those of PP filled with 20 wt.% WF, while the impact strength decreased by 87%. Highlights: WF was used as a reinforcement in polypropylene designed for 3D printingA pilot‐scale, pellet‐fed 3D printer was used to print hollow hexagons, and then test specimens were fabricated from these hexagons for mechanical propertiesThe tensile and flexural properties of 3D printed neat polypropylene improved, while the impact strength decreased after adding 20 wt.% WF to the neat PP. [ABSTRACT FROM AUTHOR]

This study investigates the effects of process parameters including scanning strategy, build orientation, and hatching distance on the mechanical properties of AlSi10Mg parts produced by Laser Powder Bed Fusion (L-PBF). The experiment varied these parameters within defined ranges and used statistical analysis to evaluate their impact on tensile strength and ductility. Results showed that scanning strategy had the greatest influence, followed by hatching distance, while build orientation affected anisotropic properties. Microstructural analysis showed clear correlation between process conditions and mechanical strength, thereby showing the underlying mechanisms that govern material behavior. Moreover, Machine learning models, including Random Forest Regression (RFR), Support Vector Regression (SVR), and Artificial Neural Networks (ANNs), were applied to predict tensile strength and ductility characteristics. RFR and SVR outperformed ANNs, showing high predictive accuracy with limited datasets. These findings emphasize the importance of optimizing L-PBF process parameters to minimize anisotropy and achieve consistent mechanical properties in produced parts. [ABSTRACT FROM AUTHOR]

Al7075 is employed as the matrix material and sugarcane bagasse ash (SBA) is a reinforcing material in this work, which is targeted at creating lightweight metal matrix composites (MMCs) at a reasonable cost. Hybridized improved composite castings have been produced and industrial as per ASTM standards with changing wt.% of 0%, 4%, 8%, 12%, and 16% wt.%, correspondingly, after mechanical testing for the evaluation of their strength. It is tested for hardness, tensile, impact, and flexural strength. Composites with hybrid enhanced metal matrix have greater tensile, hardness, and flexural strengths than single-reinforced MMCs. The composite's tensile and flexural strengths were boosted by a 12 wt.% increase in bagasse ash, which resulted in maximum values of 96.42% tensile and 23.58% flexural strength, respectively. As the bagasse weight percentage grew over 12%, these values fell, although Bagasse ash AA7075's impact and ductility improved slightly. [ABSTRACT FROM AUTHOR]

Experiments using carbon fiber reinforcing nylon composite produced by fused deposition modeling were conducted to determine mechanical parameters such as impact strength, tensile strength, and flexural strength. Four parameters—layer thickness, printing speed, raster angle, infill density, and twenty-seven runs—were used in the Box–Behnken technique of experimental design. Carbon fiber–nylon composite materials have flexural strengths that range from 20.12 to 25.89 N/mm2, tensile strengths that range from 22.75 to 34.35 N/mm2, and impact strengths that range from 0.37 to 0.72 kJ/m2. Tensile strength was significantly affected by printing speed, while impact and flexural strength was mainly influenced by layer thickness and raster angle. A scanning electron microscope was used on the broken sample to investigate the failure mechanism. Cavities, hillocks, smearing, fracture, ridges, pores, clusters, particle pullout, delamination, deep hole, protrusion, void, crack, infill gap, and interface all have an impact on composite fracture mechanisms. [ABSTRACT FROM AUTHOR]

Lightweight and highly strong polymer composites are popular and used in a variety of industries, such as consumer products, electronics, packaging, healthcare, textiles, and aviation. This study examines the production of hybrid polymer nano composites (HPNCs) and their mechanical and physical characterization. HPNCs were developed by embedding eight layers of bidirectional Banana and Kevlar fiber along with nano‐graphene oxide (GO) and epoxy as the matrix material. The novelty in this research was done by employing an ultrasonication machine for uniform dispersion of nano‐sized GO particles and varying the stacking sequence of fiber (KKBKKBKK) followed by variation in GO (0, 0.25, 0.50, 0.75, and 1) wt.% in HPNCs. The optimum values of various mechanical properties such as flexural strength, tensile strength, hardness, and inter‐laminar shear strength were found for the 0.50 wt.% of GO which are 532.13, 552.42, 88.12, and 53.08 MPa, respectively. The optimum impact strength of 878.87 J/m was obtained at 0.25 wt.% of GO. Densities, void content, and water absorption tests were done under physical characterization. The surface morphology and homogeneity of HPNC were done using the FE‐SEM test. [ABSTRACT FROM AUTHOR]

This study focuses on achieving enhanced mechanical properties of the welded joints, which is critical for the applications of mild steel (MS) plates in various industries. In this regard, a systematic approach is used to adjust welding parameters such as welding current and workpiece thickness in shielded metal arc welding (SMAW), with the objective of identifying the optimal combination that maximizes weld quality. The experiments were planned with the help of Taguchi's L9 orthogonal array method in order to reduce experimental cost and time. The weld quality is optimized by determining the signal-to-noise ratios of weld penetration, tensile strength, impact strength, and microhardness for each experimental sample. As a result, 110 A welding current is obtained as the optimal SMAW parameter for a 5 mm thick MS IS 2062 Grade B plate. This optimized result has also achieved 394.78 N/mm2 tensile strength and 53 J of impact resistance for the respective specimen. Besides, research not only enhances understanding of the SMAW process but also offers practical implications for industries requiring high-performance welded joints in MS structures. Additionally, this study can assist upcoming researchers in optimizing any existing welding procedures. [ABSTRACT FROM AUTHOR]

Al-7075 alloy with nano-SiC composite has superior mechanical properties that can be used in automobile, aerospace and defence sector to manufacture various components and body structures. In the present study, Al-7075 alloy with nano-SiC composite with different wt% of nano-SiC particles has been fabricated by the ultrasonic-assisted stir casting method. Uniform mixing of the nanosized SiC particles in the Al-7075 alloy has been achieved from ultrasonification and as-cast and T6 heat-treated samples were prepared. The diverse mechanical properties such as tensile strength, impact strength and hardness have been examined for the as-cast samples with different wt% of nano-SiC and T6 heat-treated samples. [ABSTRACT FROM AUTHOR]

Highlights This study investigates the effect of atmospheric plasma activation (APA) treatment on the thermomechanical performance of adhesively bonded skins of composite sandwich panels. The investigations show that APA treatment enhances surface wettability through the water contact angle measurements, and adhesion between the skin and honeycomb core of the panels under mechanical tests. Specifically, APA treatment results in an 11% increase in flatwise tensile strength and a 12% enhancement in the impact strength of the sandwich laminates. Flatwise tensile tests reveal superior tensile strength and toughness in APA‐treated specimens, with fracture patterns suggesting more robust adhesion. Charpy impact test results confirm increased energy absorption, reflecting better mechanical resilience. Scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) techniques are utilized to validate these findings. Overall, APA treatment proves to be an effective technique for enhancing the performance of composite sandwich panels, offering improved adhesion, strength, and impact resistance. This approach holds significant promise for advancing high‐performance composite materials in various engineering applications. APA treatment enhances wettability and adhesion in sandwich panels. Improved adhesive distribution between skin‐core after sandwich manufacturing. 11% increase in tensile strength and 12% in impact strength with APA. Better toughness and energy absorption via SEM and DMA support in APA. [ABSTRACT FROM AUTHOR]

Achieving high-performance 3D printing composite filaments requires addressing challenges related to fibre wetting and uniform fibre/polymer distribution. This study evaluates the effectiveness of solution (solvent-based) and emulsion (water-based) impregnation techniques to enhance fibre wetting in bleached flax yarns by polylactide (PLA). For the first time, continuous viscose yarn composites were also produced using both impregnation techniques. All the composites were carefully characterised throughout each stage of production. Initially, single yarns were impregnated and consolidated to optimise formulations and processing parameters. Solution impregnation resulted in the highest tensile strength (356 MPa) for PLA/bleached flax filaments, while emulsion impregnation yielded the highest tensile strength for PLA/viscose filaments (255 MPa) due to better fibre wetting and fibre distribution. Impregnated single yarns were then combined, with additional polymer added to produce filaments compatible with standard material extrusion 3D printers. Despite a reduction in the mechanical performance of the 3D-printed composites due to additional polymer impregnation, relatively high tensile and bending strengths were achieved, and the Charpy impact strength (>127 kJ/m2) for the viscose-based composite exceeded the reported values for bio-derived fibre reinforced composites. The robust mechanical performance of these filaments offers new opportunities for the large-scale additive manufacturing of structural components from bio-derived and renewable resources. [ABSTRACT FROM AUTHOR]

Highlights This study is an attempt to develop high‐quality hybrid composites via functionalization (for homogeneous distribution) of the graphene nanoplatelets (FGNP) and then doping to carbon fiber reinforced especial aviation epoxy matrix (Araldite LY5052) via vacuum bagging molding (VBM). The utilized materials were characterized by UV–Vis spectroscopy, tensile, impact, hardness tests, and fracture mode analysis using a scanning electron microscope (SEM). The results revealed a 92% (502.5 MPa) and 85% (490 MPa) improvement in tensile strength values by doping the 1 and 1.5 wt% FGNPs, respectively. There was an improvement in impact strength with the addition of FGNP; a 28% (3.23 J/mm2) increase was achieved in the nanocomposite with 1 wt% FGNP added, and there was a decrease again in the nanocomposite with 1.5 wt% FGNP added. However, it was still 12% (2.83 J/mm2) better than the neat composite. In addition, the results of examining the fractured surface structures of the impact and tensile test specimens were compatible with these results. It reveals a significant separation of fiber‐matrix bonds with 1.5 wt% FGNP contribution. While tensile and impact strengths peak at 1 wt% FGNP value and decrease afterward, hardness values increase in parallel with the increase in FGNPs. Composites were developed by functionalized graphene nanoplatelets (FGNP). The fiber‐matrix interface was strengthened with FGNP interphase. A 92% tensile strength increase was achieved with 1 wt% FGNP additives. 28% in impact strength and 55% in hardness increase by 1 wt% FGNP. The morphology confirmed that the FGNP interphase filled the interface. [ABSTRACT FROM AUTHOR]

The high‐strength and lightweight carbon fiber‐reinforced composites are widely used in various industries. Fused Filament Fabrication (FFF), the most cost‐effective Additive Manufacturing (AM) technology, has gained significant application advantages in the industry. The objective of this study is to improve the toughness of the carbon fiber‐reinforced polyamide composites used for FFF. In this work, HDPE was selected to reduce the hygroscopicity of PA6 while lowering the cost, carbon fiber was introduced to reinforce the PA6/HDPE blend. The elastomer POE‐g‐MAH was applied to increase the toughness of the composites as well as to improve the compatibility of the incompatible system of PA6/HDPE. Mechanical tests and micromorphology observation were carried on the FFF printed samples. The test results show that when 20 phr POE‐g‐MAH was added, optimum mechanical properties were obtained for the composites with about 18.9 wt% carbon fiber content. The tensile strength reached 94.1 MPa, and the notched impact strength reached 21.0 kJ/m2, which were 180.8% and 610.7% higher than that of the neat PA6, respectively. It is applicable for various applications that require high‐impact strength, including automotive parts and some machine components. Highlights: The PA‐2CF‐C20 composite exhibits high strength and high toughness, the tensile strength reaches 94.1 MPa and the notched impact strength reaches 21.0 kJ/m2.Successfully prepared cost‐effective and high‐performance filament for FFF 3D printers. [ABSTRACT FROM AUTHOR]

Natural fiber-reinforced biocomposites offer sustainable alternatives to conventional plastics. This study investigates the development of biocomposites using coconut spathe fiber, a renewable byproduct, reinforced with corn starch and poly(vinyl alcohol). The composites demonstrated significant mechanical properties, including a tensile strength of 46.8 MPa, flexural strength of 42.1 MPa, and an impact strength of 11.2 kJ m−2. Water absorption was limited to 33.6% after 24 hours, indicating hydrolytic stability. Biodegradation tests confirmed the complete breakdown of the material in composting conditions. These findings highlight the potential of coconut spathe-based biocomposites for applications in the automotive and packaging industries, addressing the need for sustainable and biodegradable materials in place of non-degradable thermoplastics. [ABSTRACT FROM AUTHOR]

This work aims to assess the possibility of using packaging industry waste to modify polypropylene products (PPs). The products were made in the form of extruded foil and injected samples. The products were produced using regranulate made of polypropylene cast foil. Maleic anhydride-modified polypropylene (MAPP) and polyolefin elastomer (POE) with a glycidyl ester functional group were used to modify the polypropylene. The samples were produced based on 50% foil waste reground and 50% pure PP. The rheological properties of the blends were assessed using the melt mass flow rate (MFR) technique; thermal properties using the differential scanning calorimetry method (DSC). The products manufactured using the injection molding method were subjected to an analysis of mechanical properties, such as tensile strength and impact strength. Also, in the case of film samples, tensile strength was assessed. Color-change assessments with CIE L*a*b* were carried out for all materials. Injection-molded products based on recycled metallized cast foil showed favorable mechanical properties such as tensile strength (1 MAPP = 26.7 MPa; 2 MAPP = 27.1 MPa), which was higher than the original material (cPP = 20.7 MPa). Also, for the films produced from regrind, the tensile strength was at a level similar (1 MAPP = 24.6 MPa; 2 MAPP/POE = 25.1 MPa) to the films extruded from virgin materials (cPP = 24.9 MPa). The introduction of a POE additive to the blends resulted in increased impact strength (1 MAPP/POE = 31 kJ/mol; 2MAPP/POE = 18 kJ/mol; 3 MAPP/POE = 11 kJ/mol) in relation to unmodified samples (cPP = 7 kJ/mol). The introduction of a POE additive to the tested mixtures improved the impact strength of the injected products by almost 4 times for sample 1 MAPP/POE and 2.5 times for sample 2 MAPP/POE in comparison to virgin cPP. These studies confirmed that foil waste can be successfully used to modify polypropylene products shaped both in the injection and extrusion processes. [ABSTRACT FROM AUTHOR]

The composites are prepared by reinforcing with 7-mm-short treated coconut tree primary flower leaf stalk fiber (CPFLSF) and palmyra palm leaf stalk fiber (PPLSF) in the polyester matrix. Compression molding was used to fabricate the hybrid composite plates. The 7C10P20C (treated 7-mm coconut tree primary flower leaf stalk fiber/palmyra palm leaf stalk–reinforced polymer hybrid composite) showed the maximum tensile strength (47.14MPa), flexural strength (73.56MPa), and impact strength (10.56kJ/m2), respectively. Reinforcement of alkali-treated palmyra palm fibers enhanced the loss modulus, storage modulus, and damping factor (tanδ) for the 7C10P20C. The final thermal decomposition stage of the 7C10P20 hybrid composite takes place at 550°C with a maximum residual mass of 26%. The morphological study confirms the less pullout, fracture surface, and better bonding between the matrix and reinforcement of the 7C10P20C. A minimum amount of water was absorbed by the 7C10P20C during the water absorption test, due to the maximum hydrophobic nature. In the dynamic mechanical analysis (DMA), maximum storage modulus (E′) and loss modulus (E″) were observed in the values of 1392MPa and 259.2 MPa obtained for the 7C10P20 hybrid composite. The measured property results are compared with each other and with various natural fiber polymer composites and reported in this work. The results demonstrate that the produced composites are stable, with high tensile strength and bending rigidity, allowing material engineers to use the material in light-load applications. [ABSTRACT FROM AUTHOR]

The polypropylene (PP) was modified by β-nucleating agent to prepare PP masterbatch with the β-nucleating mass fraction of 5%. The PP masterbatches are then injection molded with PP in various ratios to form PP standard test specimens, which are subsequently subjected to mechanical property testing. The results showed that the β-nucleating agent had a significant toughening effect on the homopolymer PP 1100N. When the mass fraction of β-nucleating agent is 0.02%, the notched impact strength at room temperature increases from 5.0 kJ/m² to 9.1 kJ/m², with an increase of 82%. At a mass fraction of 0.15%, the notched impact strength at room temperature reaches its maximum, increasing from the original 5.0 kJ/m² to 11.5 kJ/m², with an increase of 130%. The low-temperature impact strength also increases with the addition of β -nucleating agents, from 2.0 kJ/m² to 2.6 kJ/m², with an increase of 30%. The incorporation of β -nucleating agents affects the tensile properties of the material. At a mass fraction of 0.05% of β-nucleating agent, the tensile strength reaches a maximum of 30.98 MPa, which is a 13.27% increase in tensile strength compared to the blank sample without addition, and the elongation at break also increases from 708.95% to over 1 060.00%. The addition of β-nucleating agents affects the bending properties of the material and reduces its rigidity, but the impact is not significant. [ABSTRACT FROM AUTHOR]

The article uses carbon fiber (CF) to prepare CF reinforced polycarbonate/acrylonitrile-butadiene-styrene copolymer (PC/ABS) composites, and studies the influence of CF on the mechanical and thermal properties of PC/ABS composites, in order to obtain the optimal content of CF. Mechanical property analysis shows that as CF increases, the tensile strength and flexural strength of CF reinforced PC/ABS composites continuously increases, while the impact strength first increases and then decreases. Thermal property analysis shows that with the continuous addition of CF, the heat deflection temperature of CF reinforced PC/ABS composites continues to increase, and the melt flow rate (MFR) first increases and then decreases. When the CF mass frction is 15%, the comprehensive mechanical and thermal properties of CF reinforced PC/ABS composites are optimal. Compared with the material without CF, the tensile strength, flexural strength, and impact strength are increased by 134.7%, 133.3%, and 69.6%, respectively, the heat deflection temperature is increased by 39 °C, and the MFR is increased by 27.8%. [ABSTRACT FROM AUTHOR]

The high-dose ultraviolet (UV) aging test of high density polyethylene (HDPE) composites modified by different contents of compound light stabilizer was tested by UV aging test chamber with UV irradiation intensity of 500 W/m². Fourier transform infrared spectroscopy (FTIR) test showed that the carbonyl index was positively correlated with the aging degree of HDPE. The aging rate of HDPE was significantly reduced by the addition of ultraviolet additives. The molecular weight of modified HDPE was analyzed by rotating rheology, which could found that the crosslinking reaction rate of HDPE was inhibited more with the increase of ultraviolet additives in the early aging period. Combined with the above analysis and mechanical test results, it was found that when the modified HDPE material needed to withstand the total ultraviolet irradiation of 200 kWh/m², the modified HDPE material could maintain good properties by only adding 1.2 phr compound light stabilizer in 100 phr matrix. The retention rates of elongation at break, tensile strength and notch impact strength were 57.7%, 63.8% and 105.0%, respectively. [ABSTRACT FROM AUTHOR]

With the advances in additive manufacturing, polyetheretherketone (PEEK), a biocompatible polymer, can be used in biomedical applications such as spinal implants. This paper aims to investigate the evolution of the microstructure of PEEK parts manufactured by material extrusion (MEX)‐based additive manufacturing with different printing parameters. The effect of layer thickness (LT) and nozzle diameter on mechanical properties was investigated using tensile, Charpy impact, and short beam strength (SBS) tests. Two different LTs, 0.1 and 0.2 mm, and two different nozzle diameters, 0.6 and 0.8 mm, were used as printing parameters. By increasing the LT, tensile strength dropped by around 24%, and impact strength by almost 55%. Moreover, altering the LT resulted in a 15% decrease in interlaminar shear strength (ILSS) from the SBS test. In addition, increasing the nozzle diameter also led to a significant reduction in all of the results as tensile strength, Charpy impact strength, and ILSS. The results were also consolidated by scanning electron microscopy. The main findings were that increasing LT leads to an increase in microstructural defects that act as stress concentrators. Following the tests, response surface methodology (RSM) was used to determine optimal printing parameters. In the end, using the optimum printing parameters from the RSM study, a structural analysis of a MEX‐printed spinal implant was conducted through finite element method, considering the loading cases mimicking daily human body motions. Highlights: As layer thickness increased, tensile and impact strength dropped.Tensile and impact strength dropped truly with increasing nozzle diameter.SEM revealed that increasing layer thickness causes more microstructural flaws.FEM analysis showed that PEEK‐based implant provides structural integrity. [ABSTRACT FROM AUTHOR]

The laser powder bed fusion process for metals (LPBF‐M) results in the development of stochastic surface features that significantly influence the interactions between parts and their surrounding environment, as well as their mechanical properties. The process parameters influence the surface quality, which is quantified by the surface roughness. Therefore, customizing the surface roughness during the build process can significantly contribute to obtaining ready‐to‐use parts, reducing the need for extensive surface posttreatments. This paper utilizes theoretical estimations of melt pool depth under iso‐linear energy density, iso‐power, and iso‐temperature manufacturing process parameter conditions. These estimations are then compared with experimental evaluations of surface roughness and tensile strength in upright‐built specimens to extract the trends in terms of the input energy versus roughness, and the input energy versus tensile behavior. The results show that iso‐energy values yield similar roughnesses due to the consistent expected melt pool depth. Moreover, an increase in melt pool depth generates higher surface roughness, while smaller melt pool dimensions result in improved roughness. Additionally, a comparison between the melt pool size and tensile test performance reveals a detrimental impact on the tensile strength for specimens estimated to have smaller melt pool depths. [ABSTRACT FROM AUTHOR]

Abstract In this study, Washingtonia fibres (AW) and Kenaf fibres (KF) were utilized as environmentally friendly fillers to improve the quality of the resin matrix. The mechanical, morphological, and physical properties of the WA/KF biocomposites were assessed throughout this research. The mechanical tests (tensile strength and moduli, elongation at break, flexural strength along with moduli, and the impact properties) were carried out. The hybrid biocomposites (3AW/7KF) exhibited the highest tensile strength (16.05 MPa) and modulus (4.6 GPa) among pure and other hybrid biocomposites. The impact strength and resistance of hybrid biocomposites (1AW/1KF and 7AW/3KF) showed the highest impact strength (1694 J/m2) while the 3AW/7KF hybrid biocomposite, the impact strength value was 1630 J/m2 (17.2 J/m). SEM images indicated good distribution and bonding of hybrid biocomposites. The investigation using morphological tests (Scanning Electron Microscopy (SEM)) displays the longitudinal roughness on the surface, which acts as a very significant function in the adhesion between the AW/KF fibres and the resin. Furthermore, the results of SEM confirm better bonding in the biocomposites, fibre fracture, pull-out, fibre shearing, and tearing in the pure and hybrid composites. From the water absorption test, it was observed that, when increasing the immersion time of biocomposites, the WA percentage of KF biocomposite significantly increased (37%) compared to other biocomposites. However, the hybrid and pure biocomposites exhibited more resistance to increase the WA percentage after increasing the immersion times, compared to other biocomposites. Furthermore, the thickness swelling (TS) of hybrid biocomposites increased compared to pure biocomposites. The biocomposite sample (3AW/7KF) was thicker on the 7th day exhibiting the greatest increases in thickness swelling (4.98%) while the hybrid biocomposite exhibited greater WA value compared to other correspondence samples. Finally, the KF and AW hybrid blends can be appropriate for several applications, for example, textiles, machinery part production industries, medicine, and automobiles, and construction, specifically buildings, bridges, and structures such as boat hulls, swimming pool panels, racing car bodies, shower stalls, bathtubs, storage tanks. Overall, the findings exhibit that the hybridisation of natural fibres (KF/AW) is a sustainable approach for obtaining biocomposites with advanced mechanical and thermal performance. Hence, they could be used in numerous specific applications, including automobile panels, structural products, sporting goods and furniture tools.

This study delves into the influence of inherent minerals within coal gangue (CG) on the preparation and performance of coal gangue /polyethylene (CG/PE) composites, focusing on the role of SiO2 in interfacial compatibility. A systematic examination unveils the consequences of varying SiO2 content on physical, mechanical, thermal, and microstructural attributes of the composites. SiO2 incorporation significantly improves physical properties, boosting density and hardness but impacting tensile strength negatively. It enhances bending strength and modulus while diminishing tensile strength. Judicious SiO2 addition enhances thermal stability, but excess SiO2 may compromise thermal decomposition. Microstructural analysis, including SEM and FTIR, elucidates SiO2‐PE interactions, primarily through physical entanglement. SiO2 introduction promotes more ordered PE molecular chain arrangements, elevating composite crystallinity. In summary, this study provides in‐depth insights into SiO2's mechanistic impact on CG/PE composite properties, laying a robust foundation for designing environmentally friendly composites. These findings hold promise for advancing sustainable materials science and engineering. Future research may explore SiO2 optimization for specific applications and synergistic effects with other fillers in composites. Highlights: SiO2 greatly improves the properties of CG/PE composites with detailed exploration.Reveals the specific SiO2‐PE interaction mechanism for a better comprehension.Performs structural analysis via XRD with valuable findings presented.Promotes pioneering advancements in eco‐friendly materials with broad significance. [ABSTRACT FROM AUTHOR]

This research proposes a novel sustainable composite using basalt (B), hemp (H) and polyurethane rubber (Pu) reinforced in nano clay functionalised epoxy matrix for sacrificial structural applications prone to low‐velocity impact (LVI). To this end, symmetric and asymmetric laminates such as HHHH, BBBB, BHHB, BHPuHB, BBPuHH and BPuBPuHPuH are fabricated using compression molding techniques and subjected to LVI at three different impact energies of 19.66, 39.39, and 59.05 J. The hemp fibers were treated with NaOH solution before fabrication. Material characterization such as X‐ray diffraction, Raman spectroscopy and morphological studies has been carried out. The impact and post‐impact properties of the proposed composites are experimentally evaluated and validated with the finite element (FE) results. The effect on the residual tensile strength degradation of laminates at different interlayers and energy levels is also investigated using the Caprino analytical model. The barely visible impact damages (BVID) are investigated through non‐destructive dye‐penetration tests, which facilitate easy identification of the prominent LVI damages like "Plateau" and "Cliff‐drop" impressions. Based on the impact energy absorption and residual tensile strength, proposed laminates followed BHPuHB > BBBB > BHHB > HHHH. The experimentation suggests that Polyurethane core laminates support maximum impact energy absorption by favoring a structural change in interlayers. Also, the residual tensile strength decreases as impact velocity increases. Highlights: Low‐velocity impact behavior of sustainable composites is experimented.Basalt, hemp and polyurethane rubber are reinforced in nano clay epoxy matrix.A FE framework to validate the experimentation is proposed.Dye penetrant NDT is adopted to investigate the damages.Morphological studies are conducted to understand LVI responses. [ABSTRACT FROM AUTHOR]

The effect of resin modification through the incorporation of the biomass waste in the form of seashell powder on the mechanical properties of basalt fiber–reinforced epoxy/seashell composites is examined through experimental investigations. The resin modification is done through the addition of seashell powder in 5, 10, 15, and 20 wt.%. The modified resin is then reinforced with basalt fiber mat and the required laminate is obtained through compression molding technique. The specimens required for various mechanical tests, such as flexural, tensile, inter laminar shear (ILSS), and the impact strengths, are cut from the laminate as per the standard ASTM dimensions. The mechanical test results indicate that through the addition of the seashell filler additional toughening mechanisms are introduced which improves the strength of the composite laminate. The improvement in the flexural modulus value for all the laminates made from modified resin indicates the ability of the laminate to deflect the applied load effectively and efficiently. The optimum wt.% addition of seashell filler into the resin is found to be 5% for flexural, ILSS, and impact strength while for tensile strength it was observed to be 10%. The addition of higher wt.% loading of seashell filler into the resin has rendered the resin too thick and viscous with minimum flowability. Thus, there is a reduced wettability of the modified resin with the basalt fibers due to which the strength of the laminates reduces. The SEM analysis indicates widespread delamination for higher wt.% addition of the seashell filler into the resin. [ABSTRACT FROM AUTHOR]

In this work, a series of functionalized MWNTs/EP composites were fabricated by epoxy resins (EP) and functionalized multi-walled carbon nanotubes (MWNTs). The dispersion of MWNTs in the EP matrix, through different methods, i.e., stirring, solvent, and emulsion dispersion, was investigated. Results show that the homogeneous dispersion of the MWNTs/EP composites was achieved, and the glass transition temperature (Tg) increased to 119℃. The tensile strength and modulus of elasticity were 1.690 GPa and 62.5 MPa, respectively, and the impact strength reached 4.97 KJ/m2 for the MWNTs/EP, with a 6 wt% MWNT loading. In addition, the resistivity of the MWNTs/EP composites decreased from 1013 to 106 Ω·cm in the initial EP matrix. The incorporation of MWNTs and a novel dispersion method effectively modified the mechanical and electrical properties of the initial EP matrix, and improved the inherent structural defects of the initial EP matrix, reducing the brittleness and impact resistance. With further research, this composite material has the potential to further broaden the application field of novel materials based on the EP matrix. [ABSTRACT FROM AUTHOR]

Textile waste is a significant environmental problem that contributes to landfills and pollution that causes greenhouse gas emissions. Recycling and reusing textiles and developing a product from waste is feasible. Moreover, it can bring new opportunities in the recycling industry and contribute to the circular economy. However, choosing a material to produce a composite and finding out all its properties is a big challenge that needs to be explored more. This research is based on the characterization of a natural fiber composite from textile waste for domestic as well as industrial applications. It involves the production of composite material from textile waste, which has suitable mechanical strength and impact properties for use in the construction, automotive and ballistic industries. Three recycled non-woven wastes -- cotton, polyester and cotton/polyester blend -- are used. A roller speed of 200 rpm is chosen to produce carded mesh. The shredded textiles are then mixed with epoxy resin. The pressing technique with the help of compression moulding is used to produce composite samples. Mechanical tests were carried out to evaluate the young's modulus, tensile strength, flexural strength, impact strength and breaking elongation of the composites. It was found that with an increase in the volume percentage of fibers, the storage modulus of the prepared composites shows a higher value. Young's modulus, elongation at break, flexural strength and impact toughness increase with volume fraction up to 40 percent, but then the properties start to decrease again when mixing is done above 40 percent to 50 percent. The novelty lies in utilizing pre and post-consumer textile waste, including discarded personal protective equipment (PPE) and other textile wastes from the COVID-19 pandemic, as reinforcing fibers which contributes to textile waste recycling and also providing a better alternative to existing materials like pine wood, maple, oak and wood plastic composite for possible use in domestic items as well as construction and automotive industry at a lower cost. [ABSTRACT FROM AUTHOR]

The increasing application of additively manufactured (AM) materials in engineering and biomedical fields highlights the necessity of understanding their mechanical behavior, particularly with complex lattice structures. Polylactic acid (PLA), a popular biopolymer in additive manufacturing, exhibits mechanical characteristics highly dependent on its structural design. This research investigates the quasi‐static puncture failure analysis and mechanical characteristics of additively manufactured (AM) polylactic acid (PLA) materials with various lattice structures. The mechanical behavior, including tensile strength, flexural properties, interlaminar shear strength (ILSS), Izod impact resistance, and quasi‐static punch shear strength (QS‐PSS), was investigated following the respective ASTM protocols. Results indicate a 6% increase in tensile strength, to ca. 28 MPa, for the triangular PLA lattice structure compared with plain lattice structures. In the flexural test, the hexagonal structure showed a 13% increase in bending strength, to ca. 45 MPa, compared with the plain structure. Additionally, the hexagonal PLA lattice structure exhibited a 24% increase in shear strength, to approximately 8 MPa, over the plain lattice structure in the interlaminar shear strength analysis. In the Izod impact analysis, the plain lattice structure demonstrated a 17% increase in impact strength, to ca. 278 J/m, compared with the circular structure. A stainless‐steel hemispherical indenter was employed to investigate the quasi‐static punch shear behavior (QS‐PSS) of different lattice structures. The triangular structure displayed increased total energy absorption capacity and specific energy absorption of ca. 19 J and 0.529 J/g, respectively, compared with other lattice structures. These results are important for the creation of additively manufactured PLA lattice structures, improving the puncture resistance of advanced composites. Highlights: Polylactic acid (PLA) lattice structures were fabricated.Plain, circular, triangular, and hexagonal lattice structures were investigated.Lattice structures were used as reinforcements.The triangular structure demonstrated improved strength.The triangular structure reduced crack formation and propagation. [ABSTRACT FROM AUTHOR]

The shear‐thickening gel (STG) is introduced as a toughening agent into the epoxy resin (EP) to improve the toughness and impact resistance of the EP without significantly increasing its viscosity. By utilizing the unique BO dynamic bonds present in STG, the EP/STG composite exhibits remarkable toughness at low strain rates due to the gradual disentanglement of molecular chains. Conversely, at high strain rates, the disentanglement of molecular chains is hindered, resulting in a pronounced impact hardening effect and overall superior impact resistance. Our findings reveal that when STG is added at a concentration of 15%, the EP/STG composite material attains its peak mechanical performance. Specifically, it demonstrates a tensile strength of 31.8 MPa and a modulus of elasticity of 550.6 MPa. Furthermore, compared to pure EP, the EP/STG composite experiences an increase in elongation at break and impact strength by 40% and 8.1%, respectively. Additionally, the introduction of hydroxyl and B atoms in STG promotes the ring‐opening reaction of epoxy groups during the curing process of the EP, thus accelerating the curing reaction rate. These insights provide a solid theoretical foundation for optimizing the performance of EPs in engineering applications. Highlights: The STG was actively utilized to enhance the toughness of EP.The modified EP system exhibits significant improvements in toughness and impact resistance without a notable increase in viscosity.The promotional effect of STG on the curing of EP systems was revealed through curing kinetics analysis and rheological analysis. [ABSTRACT FROM AUTHOR]

In this study, resveratrol was substituted for phenol in different molar ratios (4%, 8%, 12%, 16% and 20%) with lignin, phenol and formaldehyde as raw materials, and a new resveratrol modified lignin-based phenolic resin (R-LPF) with high glass transition temperature (Tg) and improved mechanical properties was synthesized. The curing behaviors of phenolic resin (PF), lignin phenolic resin (LPF) and R-LPF were investigated. The thermal mechanical properties, thermal stability, comprehensive mechanical properties, frictional properties and morphology were systematically tested and analyzed. The results show that the highest Tg of the modified R-LPF reaches 346.2 °C. The Ts reaches 231.5 °C, and the residual carbon rate reaches 66.2% at 800 °C. For 12% substitution ratio, the maximum tensile strength, bending strength and impact strength are respective 28.72 ± 1.10 MPa, 57.58 ± 1.95 MPa and 3.14 ± 0.19 KJ/m2. Compared with PF and LPF, the tensile strength of R-LPF is increased by 21.5% and 40.4%, and the bending strength is increased by 6.5% and 30.4%, while the impact strength is increased by 38.9% and 58.6%, respectively. The wear resistance is also significantly improved. The modified R-LPF structure has good rigidity, high crosslinking density, excellent mechanical and thermal properties, and it makes up for the defects of system performance decline caused by the introduction of lignin and provides a direction for the development of green high-performance phenolic resin. [ABSTRACT FROM AUTHOR]

Poly(butylene succinate) (PBS) was melt-blended with paramylon based mixed ester, paramylon propionate hexanoate (PaPrHe) and characterized for its morphology, thermal and mechanical properties. The PBS/PaPrHe blends were found to be immiscible throughout the loading range of PaPrHe (10–90 wt%), with individual glass transition peaks. Due to the immiscibility, there was phase separation observed in the bulk, evident by sea-island morphology. However, further observation of the micro-structure revealed that, in low PaPrHe loading (10–30 wt%), there was a micron to sub-micron order distribution of PBS particles and partially miscible PBS/PaPrHe phase. On increasing the PaPrHe to 50 wt% and beyond, the sub-micron scale domains fused to form a co-continuous morphology. As a result, the impact strength of PBS increased from 6.6 to 16.4 kJ/m2 in the 50/50 blend. Under tensile loading, the strength at break and elongation decreased after the introduction of less-flexible PaPrHe particles in the blend. This could be countered by uniaxially stretching the blended films with 10–30 wt% PaPrHe, after which the tensile strength increased by up to 380% (from 33–52 MPa to 165–200 MPa) compared to the unstretched films, attributable to the increased degree of orientation of the molecular chains. In terms of thermal processability, all the blend ratios had high thermal degradation temperature (>350 °C), higher than the melt-flow temperature (124–133 °C) providing a wide processing window. Overall, PBS/PaPrHe blend is a novel bio-based blend with properties suitable for packaging, mulching, and related applications. [ABSTRACT FROM AUTHOR]

Introduction: This study was carried out to assess the effect of natural wool fiber addition on the impact, tensile, and flexural strengths of the heat-cured acrylic denture base material. Methods: Short wool fibers with and without chemical surface treatment were added to polymethyl methacrylate (PMMA) at a percentage of 0.25% by weight. A total of 90 acrylic specimens were prepared and divided into three groups according to the tests performed. Impact strength, tensile strength, and flexural strength tests were evaluated. The statistical analysis of the results data was performed using the one-way analysis of variance (ANOVA) test and Tukey's post hoc test. Results: Impact strength improved significantly after adding silane-treated natural wool fibers to PMMA. However, the tested groups did not have significant differences in tensile and flexural strengths. Conclusion: Natural wool fibers in a percentage of 0.25% by weight could improve the impact strength of the acrylic denture base material after treatment with the silane coupling agent. At the same time, they did not significantly affect the tensile and flexural strengths with or without surface treatment. [ABSTRACT FROM AUTHOR]

This experiment was conducted to demonstrate that the use of the injection molding method of samples with different PBT/PA6 and PP blend ratios clearly shows the effect of the PP ratio on the mechanical properties of the blend to study and use the results for application in the manufacture of recycled plastic materials. PP/PBT/PA6 blends were mixed in the ratios of 100/0/0, 90/5/5, 80/10/10, 70/15/15 and 0/50/50. The tensile strength increased gradually, reaching the highest value in the 90PP/5PBT/5PA6 sample of 31.97 MPa, an increase of 18% compared to the 50PBT/50PA6 sample (27.1 MPa). The impact strength increased gradually from 2.83 kJ/m2 in the 70PP/15PBT/15PA6 sample to 3.55 kJ/m2 in the 90PP/5PBT/5PA6 sample, which was 5% higher than that of the sample without PP − 50PBT/50PA6. However, the flexural strength gradually decreases when adding PP to the blend, from 43.79 MPa in the sample without PP − 50PBT/50PA6 to 41.40 MPa at 80PP/10PBT/10PA6. The 50PBT/50PA6 sample had the highest stress value of 43.79 MPa. The hardness decreased gradually with increasing PP content; the value achieved at the 50PBT/50PA6 mixture was 80.2 MPa; however, at the 90PP/5PBT/5PA6 sample, the Shore D hardness achieved was 72.2 MPa. Therefore, increasing the PP content in the mixture will improve the tensile strength and impact strength but reduce the flexural strength and hardness of the sample. Our research results show that the 90PP/5PBT/5PA6 mixture has mechanical properties equivalent to PP plastic. Thus, instead of using 100% traditional PP plastic, the 90PP/5PBT/5PA6 mixture can be used, and PBT/PA6 material can be obtained from waste from producing toothbrush bristles, partly solving the plastic waste problem. [ABSTRACT FROM AUTHOR]

This manuscript presents a comprehensive investigation into the tensile strength and flexural behavior of steel fiber‐reinforced concrete (SFRC), utilizing a robust dataset comprising 457 meticulously selected data points, including 54 instances of self‐tested experimental data. The study establishes an empirical relationship governing the tensile strength of steel fiber concrete (SFC) based on the fiber reinforcement index (FRI) and the grade of concrete. The experimental study has extended its scope by testing an additional 27 full‐scale SFRC beams (rectangular cross‐sectioned) under monotonic loading to quantify the impact of tensile strength on the overall structural performance. The beam specimens feature continuous longitudinal and transverse reinforcement throughout their span, with steel fibers strategically positioned below the neutral axis. The steel fiber content was systematically varied from 0% to 2% in intervals of 0.25%. This work introduces modifications to the design of SFRC flexural members, emphasizing the consideration of tensile contribution below the neutral axis. The study integrates both experimental and analytical methodologies, providing diverse insights into the flexural behavior of SFRC beams. The proposed design methodology considers the tensile strength contribution from SFC, effectively predicting flexural capacity, particularly in scenarios involving higher volume fractions. Its applicability extends to structural design, offering insights into evaluating structural capacity for both newly designed and existing structures. [ABSTRACT FROM AUTHOR]

AbstractA non-traditional friction stir welding (FSW) is used to joint the materials that are challenging to join together by utilizing the fusion welding processes. This study investigated the influence of the welding speed ratio (υ) to rotating speed (ꞷ) on the weld quality and found the relationship between mechanical qualities and welding peak temperature. With increase in (ꞷ/υ), there was a corresponding rise in peak temperature, leading to the expansion of both the nugget zone (NZ) and the softened region within the joint. As (ꞷ/υ) increased because of the increased heat, as a result in the joint hardness decreased. The joint ultimate tensile strength (UTS) increased with increasing (ꞷ/υ), then decreased, with the maximum value reaching 84.75% of the base material at a (ꞷ/υ) of 9.6. As a result of the low (ꞷ/υ), a flexural crack formed. In comparison to the base material, the thermos mechanically affected zone (TMAZ) and the nugget zone (NZ) showed greater impact strength. The impact strengths first increased and subsequently dropped with an increase in (ꞷ/υ). The tensile specimens’ fracture surfaces showed dimples, signifying a ductile mode of fracture. [ABSTRACT FROM AUTHOR]

Hydroxy-functionalized polyacrylate rubber particles (ACR-OH) were synthesized with micrcrcrosslinked poly-butyl acrylate (PBA) as a rubber core and methyl methacrylate-hydroxyethyl acrylate copolymer (HEA) as a shell through seed emulsion polymerization. ACR-OH was mixed with triglycidyl isocyanurate (TGIC) and then added into polybutylene terylene phthalate (PBT). Owing to the reactions occurring between the hydroxyl groups on the surface of ACR particles and epoxy groups in TGIC and between the epoxy groups in TGIC and hydroxyl end-group of PBT in the melt blending process, the modified PBT (PBT/TGIC/ACR-OH) gained the good compatibility between ACR and PBT. The effect of the addition of ACR-OH and TGIC on the impact strength and tensile strength of the modified PBT were investigated. The results indicated that the addition of ACR-OH effectively improved the toughness of PBT due to good compatibility. When the addition amounts of ACR-OH and TGIC were 20 and 2 phr, respectively, the impact strength of the modified PBT reached 20. 45 kJ/m², which was 8. 4 times as high as that of pure PBT (2. 43 kJ/m²). Moreover, with the help of multi-functional TGIC, the modified PBT exhibited both good toughness and good strength at addition amounts of ACR-OH and TGIC of 8 and 2 phr, respectively. Its impact strength and tensile strength reached 10. 87 kJ/m² and 42. 1 MPa, respectively. [ABSTRACT FROM AUTHOR]

This study focuses on the experimental investigation of the mechanical properties of PBT/PC blends with varying compositions. The studied mechanical properties include tensile strength, elongation, tensile modulus, impact strength, and Shore hardness of PBT/PC blends with different PC contents. PBT, characterized by its semi‐crystalline and tough nature, contrasts with PC, known for its impact resistance and hardness. Achieving an optimal blend composition proves to be crucial for attaining the best combination of these properties. The tensile strength of the PBT/PC 30/70 blend increased by approximately 24%, with Shore hardness also experienced a 12% enhancement compared to pure PBT. This improvement is attributed to the presence of PC segments in the blend structure. Conversely, an increase in PC content led to the elongation and impact strength of the blends peaking in the PBT/PC 70/30 blend. Notably, the impact strength of the PBT/PC blend with 30% PC increased by about three times compared to PBT and 18% more than pure PC. Scanning Electron Microscopy (SEM) analysis revealed that PBT and PC segments disperse at lower PC content, while at higher content, phase separation becomes prominent. Fourier Transform Infrared Spectroscopy (FTIR) analysis indicates direct transesterification between PBT and PC, resulting in the formation of a long‐chain blend structure with random copolymer blocks. The transesterification mechanism is also supported by Differential Scanning Calorimetry (DSC) results, wherein a reduction in the crystallization temperature (Tc) and an increase in the glass transition temperature (Tg) is observed. The study concludes that the volume of these segments and their bonding play a decisive role in determining the mechanical properties. The bonding mechanism elucidated through FTIR and SEM provides valuable insights into the fabrication and property engineering of PBT/PC blends. [ABSTRACT FROM AUTHOR]

The high‐performance PPS/PEEK blends/composites were prepared with different mass ratios using polyphenylene sulphide (Solvey, Ryton®‐R‐4‐230 NA) and polyetherether ketone (Victrex, PEEK450 GL 30). All the blend samples had a single Tg, which revealed good compatibility between PPS and PEEK. The Tm was increased from 279.6 to 339.9°C due to addition of PEEK into PPS. Also, addition of PEEK into the blend increased the impact and tensile strength of the PPS material. The impact strength of the blend, PPS/PEEK (20/80) exhibited the maximum value of 113.64 J/m which was higher than that of PPS (70.66 J/m). The tensile strength of the blend was increased continuously with increasing the content of PEEK from 20 to 80 wt. % and reached the maximum value of 160.64 MPa. Additionally, milled carbon fiber (MCF) was also incorporated in order to obtain high strength PPS/PEEK blends/composites with good dielectric property. The dielectric performance of the composites was observed to increase with MCF content (in the frequency range 5.8 to 18 GHz). Highlights: This investigation relates to high‐performance PPS/PEEK blends and composites.Incorporation of milled carbon fiber resulted promising dielectric properties.Such composites may have Advanced structural EMI shielding electronics and/or aerospace applications. [ABSTRACT FROM AUTHOR]

Lightweight metal matrix composites made of aluminium are now essential in several fields, including aerospace and automotive. An important factor determining the quality and properties of the composite material is the ease or difficulty of evenly dispersing the reinforcement throughout the matrix. The goal of this research is to find out the impact of 40 and 90 µm varyingsized boron carbide (B4C) particles in A356 alloy composites. Using the liquid stir casting technique and K2TiF6 as the wetting flux, A356 alloy with 9 wt.% of B4C composites were prepared. SEM and EDS images were used to study the material's microstructure. ASTM-approved methods were used to measure the material's mechanical properties. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) confirmed that B4C particles were evenly distributed throughout the A356 alloy. The addition of B4C reinforcement to the A356 alloy matrix increased the hardness, ultimate, yield, compression, and impact strength of composites with a reinforcement size of 40 μm. The hardness of A356 alloy was enhanced by 40.7% and 34.6%, respectively, when 9 wt. % of 40 and 90 μm B4C were added. Similarly, there was a 34% increase in ultimate strength and a 31% improvement in yield strength. Both cases showed a little decrease in the ductility of the composites. Scanning electron micrographs were used to examine the morphologies of tensile fractured surfaces. [ABSTRACT FROM AUTHOR]

Polypropylene is a useful and widely consumed thermoplastic with very good properties that can be mixed with a combination of rubber and nanoparticles in order to eliminate its shortcomings. In this paper, the simultaneous combination of both the toughening effect of styrene–butadiene rubber (SBR) and the reinforcing effect of silicon carbide (SiC) nanoparticles were investigated in polypropylene matrix. Mechanical properties (tensile and impact strength [TS and IS]) of compounds were analyzed using the central composite design approach in Design‐Expert software. With two factors for input variables of SBR and SiC weight percentages, and their five levels (5, 10, 15, 20, and 25) and (0, 1.5, 3, 4.5, and 6), respectively, the central composite design approach employs 11 experiments for creation of models and the analysis of variance investigations with two output responses of TS and IS. Statistical results revealed that SBR and SiC contents had a significant effect on TS, IS, and the microstructure of compounds, as confirmed by scanning electron microscopy and energy‐dispersive spectroscopy images. To maximize all mechanical properties simultaneously with desirability functions, TS and IS of the optimum sample were computed to be 21.98 MPa and 8.66 kJ/m2 in amounts of 13.45 and 2.80 weight percentage (wt%) of SBR and SiC, respectively. Highlights: By increasing silicon carbide (SiC) in polypropylene/styrene–butadiene rubber (SBR), tensile strength decreases after a peak due to agglomeration effect.By increasing SiC in polypropylene/SBR, impact strength decreases after a peak due to agglomeration effect.By increasing SiC, the rubber particles' dimensions decrease according to scanning electron microscopy analysis.Simultaneous maximum of tensile strength and impact strength are 21.98 MPa and 8.66 KJ/m2, respectively.Optimum value of SBR and SiC in above maximums are 13.45 and 2.8 wt%, respectively. [ABSTRACT FROM AUTHOR]