Optimal Mechanical Properties Research Articles

Optimization of an Industrial Recycling Line: The Effect of Processing Parameters on Mechanical Properties of Recycled Polyethylene (PE) Blends

This study concerns the optimization of an industrial recycling line; in other terms, this paper aims to find the optimal processing parameters that allow for a decrease in the loss of stress crack resistance (SCR) using a notched crack ligament stress (NCLS) test and an increase in the gain of the elongation at break, flexural modulus, and Izod impact strength of a polyethylene (PE) blend before and after recycling. The recycling line is composed mainly of a mono- and twin-screw extruder and a filtration system. Hence, the research question is as follows: How can we optimize the recycling process, without compromising the mechanical properties of recycled polyethylene (PE) blends? To answer the research question, Taguchi’s design of experiment and grey relational analysis (GRA) for multiobjective optimization was applied. Experiments were performed according to L16 standard orthogonal array based on five process parameters: mono-screw design, screw speed of the mono- and twin-screw extruder, melt pump pressure, and filter mesh size. Based on grey relational analysis (GRA), the optimal setting of process parameters was identified, and a barrier screw and a higher screw speed for both extruders were allowed to have optimal mechanical properties. Furthermore, the analysis of variance (ANOVA) indicated that the mono-screw design and screw speed of the mono- and twin-screw extruder significantly impact the mechanical properties of recycled polyethylene (PE) blends.

Strengthening and Toughening of ZG25SiMn2CrB Steel without Tempering Brittleness via Electropulsing Treatment

High-strength low-alloy steels are widely used, but their traditional heat-treatment process is complex, energy-intensive, and makes it difficult to fully exploit the material’s potential. In this paper, the electropulsing processing technology was applied to the quenching and tempering process of ZG25SiMn2CrB steel. Through microstructural characterization and mechanical property testing, the influence of electropulsing on the solid-state phase transition process of annealing steel was systematically studied. The heating process of the specimen with the annealing state (initial state) is the diffusion-type transition. As the discharge time increased, the microstructure gradually transformed from ferrite/pearlitic to slate martensite. Optimal mechanical properties and fine microstructure were achieved after quenching at 500 ms. The steel subjected to rapid tempering with 160 ms electropulsing exhibited good, comprehensive mechanical properties (tensile strength 1609 MPa, yield strength 1401.27 MPa, elongation 11.63%, and hardness 48.68 HRC). These favorable mechanical properties are attributed to the coupled impact of thermal and non-thermal effects induced by high-density pulse current. Specifically, the thermal effect provides the thermodynamic conditions for phase transformation, while the non-thermal effect reduces the nucleation barrier of austenite, which increases the nucleation rate during instantaneous heating, and the following rapid cooling suppresses the growth of austenite grains. Additionally, the fine microstructure prevents the occurrence of temper brittleness.

Co electrospinning -poly (vinyl alcohol)-chitosan/gelatin-poly (ε-caprolacton) nanofibers for diabetic wound-healing application.

With the increasing prevalence of diabetes, the healing of diabetic wounds has become a significant challenge for both healthcare professionals and patients. Recognizing the urgent need for effective solutions, it is crucial to develop suitable scaffolds specifically tailored for diabetic wound healing. In line with this objective, we have developed novel hybrid nanofibrous scaffolds by combining polyvinyl alcohol/chitosan (PVA/CS) and gelatin/poly(Ɛ-caprolactone) (Gel/PCL) polymers through a double-nozzle electrospinning technique. In this study, we investigated the influence of the Gel/PCL blend ratio on the properties of the resulting nanofibers. Three different hybrid scaffold structures were examined: Gel/PCL (80:20)-PVA/CS (80:20), Gel/PCL (50:50)-PVA/CS (80:20), and Gel/PVA (20:80)-PVA/CS (80:20). Our findings demonstrate that the electrospun nanofibers of PVA/CS (80:20)-Gel/PCL (80:20) exhibited optimal mechanical performance, with a contact angle of approximately 54° and a diameter of 183 nm. Considering the crucial role of inhibiting bacterial adhesion in the success of implanted materials, we evaluated the cytocompatibility of the hybrid electrospun nanofibers using mouse fibroblast cells (L-929 cells). The in vitro cytotoxicity results obtained from L-929 fibroblast cell culture on the hybrid scaffolds revealed enhanced cell proliferation and appropriate cell morphology on the PVA/CS (80:20)-Gel/PCL (80:20) sample, indicating its capability to support tissue cell integration. Based on the information obtained from this study, the fabricated hybrid scaffold holds great promise for diabetic ulcer healing. Its optimal mechanical properties, suitable contact angle, and favorable cytocompatibility highlight its potential as a valuable tool in the field of diabetic wound healing. The development of such hybrid scaffolds represents a significant step forward in addressing the challenges associated with diabetic wound care.&#xD.

Impact of Sacrificial Hydrogen Bonds on the Structure and Properties of Rubber Materials: Insights from All-Atom Molecular Dynamics Simulations.

The inclusion of sacrificial hydrogen bonds is crucial for advancing high-performance rubber materials. However, the molecular mechanisms governing the impact of these bonds on material properties remain unclear, hindering progress in advanced rubber material research. This study employed all-atom molecular dynamics simulations to thoroughly investigate how hydrogen bonds affect the structure, dynamics, mechanics, and linear viscoelasticity of rubber materials. As the modified repeating unit ratio (β) increased, both interchain and intrachain hydrogen bond content rose, with interchain bonds playing a predominant role. This physical cross-linking network formed through interchain hydrogen bonds restricts molecular chain movement and relaxation and raises the glass transition temperature of rubber. Within a certain content of hydrogen bonds, the mechanical strength increases with increasing β. However, further increasing β leads to a subsequent decrease in the mechanical performance. Optimal mechanical properties were observed at β = 6%. On the other hand, a higher β value yields an elevated stress relaxation modulus and an extended stress relaxation plateau, signifying a more complex hydrogen-bond cross-linking network. Additionally, higher β increases the storage modulus, loss modulus, and complex viscosity while reducing the loss factor. In summary, this study successfully established the relationship between the structure and properties of natural rubber containing hydrogen bonds, providing a scientific foundation for the design of high-performance rubber materials.

Production and Characterization of Recycled Polypropylene Composite Reinforced with Cotton Fabric Waste

Composite materials have played an important role throughout human history, from housing early civilizations to enabling future innovations. This study explores the development of composite materials from recycled polypropylene and cotton fabric waste targeted for different applications. The composites were manufactured by the melt-mixing method. The effects of cotton fabric waste content on various composite characteristics were investigated using tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, compressive strength, and water absorption. The study showed that with an increase in cotton fabric waste content, properties such as tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and compressive strength increase up to the optimum level, while a decrease in these properties is observed after the optimal level. The maximum tensile strength of 57.84 MPa, tensile modulus of 1.31 GPa, flexural strength of 55.32 MPa, flexural modulus of 2.7 GPa, impact strength of 33.06 kJ/m2, and compressive strength of 53.68 MPa were obtained. The water absorption rate increased with an increase in the cotton fabric waste weight proportion. From the result of this study, it can be concluded that the optimal mechanical and water absorption properties were achieved at 30% cotton fabric waste content. Therefore, creating composites from recovered polypropylene and cotton fabric waste can have both environmental and financial benefits.

AZ91 Magnesium Alloy CMT Cladding Layer Processed Using Friction Stir Processing: Effect of Traverse Speed on Microstructure and Mechanical Properties.

Friction stir processing (FSP) is a solid-state treating method to enhance the mechanical properties of materials by altering their microstructure. In this study, FSP was applied to the AZ91 magnesium alloy cladding layer prepared using cold metal transition (CMT) technology, and the purpose was to investigate the effect of the traverse speed of the H13 steel stirring head under a constant rotation speed on the microstructure and mechanical properties of the cladding layer. The results demonstrated that FSP could effectively decrease the grain size of the cladding layer and lead to the dispersion and dissolution of the coarse β-Mg17Al12 second phase into the α-Mg matrix. The mechanical characteristics of the processed cladding layer were significantly enhanced compared to the unprocessed cladding layer due to the grain refinement and second-phase strengthening induced by FSP. When the stirring head rotation speed was set at 300 r/min, the average microhardness and tensile properties of the specimens showed a tendency of initially increasing and then dropping as the traverse speed increased. The cladding layer, obtained at a traverse speed of 60 mm/min, displayed optimal mechanical properties with an average microhardness, tensile strength, and elongation of 85.6 HV0.1, 278.5 MPa, and 13.4%, respectively.

Analysing the shape memory behaviour of MWCNT-enhanced nanocomposites: a comparative study between experimental and finite element analysis

Shape memory polymers (SMPs) are known for their unique ability to withstand large deformations and revert to their original shape under specific external stimuli. However, their broader application in biomedical and structural applications is restricted by limited mechanical and thermal properties. Introducing multi-walled carbon nanotubes (MWCNTs) into SMPs has proven to significantly enhance these characteristics without affecting their inherent shape memory features. This study investigates shape memory nanocomposites (SMNCs) through dynamic and thermogravimetric analyses, along with tensile, flexural, and shape memory testing, and explores fracture interfaces using scanning electron microscopy. Findings indicate optimal shape memory, thermal, and mechanical properties with 0.6 wt% MWCNT content, showcasing a shape recovery ratio of 93.11%, storage modulus of 4127.63 MPa, tensile strength of 55 MPa, and flexural strength of 107.94 MPa. Moreover, incorporating MWCNTs into epoxy demonstrated a reduction in recovery times by up to 50% at 0.6 wt% concentration. Despite a slight decrease in shape fixity ratio from 98.77% to 92.11%, shape recoverability remained nearly consistent across all samples. The study also introduces a novel finite element (FE) method in ABAQUS for modeling the thermomechanical behavior of SMNCs, incorporating viscoelasticity, validated by matching experimental results with FE simulations, highlighting its accuracy and practical applicability in engineering.

Synergistic effect of carbon nanotubes and polyvinyl alcohol on the mechanical performance and microstructure of cement mortar

Abstract Herein, carbon nanotubes (CNTs) and polyvinyl alcohol (PVA) were used as hybrid modifiers to enhance the mechanical properties of cement mortar and overcome the limitations of modification methods based on only polymers and nanomaterials. The use of PVA latex as a bridging agent with the aid of ultrasound energy effectively improved the dispersion uniformity and stability of CNTs. The results indicate that doping an appropriate amount of PVA in CNT-modified cement mortar, especially those modified with hydroxylated CNTs (h-CNTs), could synergistically improve performance. Amongst the samples, the h-CNT-modified cement mortar incorporated with 1 wt% PVA showed the optimal mechanical properties. The compressive and flexural strengths of this cement mortar increased by 33 and 42%, respectively, compared with those of cement mortars modified with h-CNTs alone. The microscopic characterisation results showed that the formation of a uniformly distributed h-CNT/PVA film network in the matrix effective filling of pores and bridging of cracks were responsible for performance enhancement.

Machine learning assisted design and optimization of plate-lattice structures with superior specific recovery force

In load carrying structures and devices, there is a growing need for shape memory polymer (SMP) metamaterials that are lightweight and have superior strength, remarkable flexibility, and substantial specific recovery force (SFR). One of the challenges is to find optimum lightweight structures with high SFR. To address this challenge, we propose a novel inverse design framework to design plate-lattice structures (PLSs) with user-defined optimum specific maximum compression strength. Consisting of three sub-frameworks, the performance of the inverse design framework was validated before it was utilized to optimize PLSs. The optimum PLSs developed are fabricated with 3D printing using a novel SMP. In addition, we have printed a solid cylinder and Cubic+Octet (control) PLSs to compare their structural capacity with the predicted structures. The optimized PLSs display 30 ∼ 170 % greater SFR compared to the control PLS and solid cylinder. These findings suggest a promising strategy for enhancing the effectiveness of actuators based on SMP mechanical metamaterials. The inverse design framework has the potential to be utilized for generating structures with user-defined optimum mechanical properties.

Experimental Investigation of Optimal Welding Parameters and Mechanical Properties of Shielded Metal Arc Welded Mild Steel Plates

Experimental Investigation of Optimal Welding Parameters and Mechanical Properties of Shielded Metal Arc Welded Mild Steel Plates

Microstructure and mechanical properties of IN738LC superalloy repaired by wide gap activated diffusion brazing method

In the current study, the effect of the weight percentage of filler and additive powder on the microstructural and mechanical properties of the wide gap activated diffusion brazing process was studied. IN738LC base metal powder and AMDRY BRB filler were used as filler metal for IN738LC superalloy brazing. Subsequently, diffusional heat treatment and aging cycle were used to modify the microstructure and mechanical properties in the restoration structure. Optical microscope and scanning electron microscope were used to identify the phases in the braze area and four-point bending tests were performed to evaluate the mechanical properties of the wide gap. For the sample brazed at 1180 °C for 30 min, heat treated at 1120 °C for 4 h, and aged at 850 °C for 24 h, the porosity and eutectic phases in the brazed area and the diffusion-affected zone maintained as low as possible. Thus, it can be referred to as the optimized sample. The samples containing 40 wt% filler had the optimum mechanical properties at ambient temperature and high temperature. Fractography showed that the place of crack initiation was mainly in the filler metal.

Mitigation of strength-ductility trade-off of CoCrNi medium entropy alloys with heterogenous structure by controlled Gd addition and annealing

In this work, we synthesized a series of (CoCrNi)100–xGdx (x = 0/0.3/0.5/1.0) medium entropy alloys (MEAs) using arc melting followed by homogenization, hot-rolling, and annealing at 700, 800, and 900 °C for 1 h. The effects of Gd content and annealing temperature on the microstructures and mechanical properties of Gd-doped CoCrNi MEAs were investigated. The heterogenous microstructure, consisting of the deformed grains, recrystallized grains and precipitates of GdNi5 phase, was obtained in the present study and it exhibited an excellent combination of strength and ductility. The optimum mechanical properties were obtained for CoCrNi MEA with 0.3–0.5 at.% Gd addition and annealed at 700 °C for 1 h to yield the heterogenous microstructure in the present study, and it had the tensile strength of ∼1.3 GPa and fracture strain of 30–40%. The synergetic hardening mechanisms included solid solution, precipitation, grain refinement, nanotwinning and pre-existing dislocation hardening. The relations among compositions, microstructures and mechanical properties of (CoCrNi)100–xGdx MEAs were addressed.

Synthesis, characterization, antibacterial efficacy, and Cytotoxicity of monoclinic KMg3(Al0.5B0.5)Si3O10F2: A novel material for anticariogenic applications

Fluorophlogopite is a well-known fluorosilicate glass-ceramic derivative known for its bioactivity, machinability and optimal mechanical properties. There is limited information regarding its antibacterial and biocompatible properties. This research paper presents the synthesis and characterization of a novel Boron-doped Fluorphlogopite [KMg3(Al0.5B0.5)Si3O10F2] aiming to improve its antibacterial properties intended for anticariogenic applications. The combustion synthesis method was employed, with oxalyl dihydrazide (ODH) (C2H6N4O2) serving as the fuel. X-ray Diffraction (XRD) analyses unveiled a monoclinic crystal system, showcasing a P21 space group, and an average crystallite size of approximately 28 nm. Morphological scrutiny divulged clustered, irregularly shaped, cluster-like structures. The energy gap was determined to be around 4.97 ± 0.0062 eV. Fourier-Transform Infrared (FTIR) spectroscopy depicted the presence of characteristic bonds. BET analysis indicated the presence of a large surface area and porous structure (mesopores), which may contribute to lower MIC and MBC values, enhancing antibacterial effectiveness. The antibacterial activity, evaluated via agar well diffusion, yielded an 8 mm zone of inhibition. Furthermore, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against S mutans were determined to be 2 mg/ml and 16 mg/ml, respectively. The biocompatibility of the synthesized KMg3(Al0.5B0.5)Si3O10F2 was assessed through the MTT assay, indicating non-toxic behavior at a concentration of 12 μg/ml with 98 % cell viability, while showing moderate toxicity with 61 % viable cells at its highest concentration of 200 μg/ml.

Effects of Zr and Y additions on microstructure and mechanical properties of cast A356 alloy

In the present work, the effects of Zr and/or Y addition on microstructure and mechanical properties of cast A356 alloy were investigated using X-ray diffractometer (XRD), differential scanning calorimetry (DSC), optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The heterogeneous nucleation effect on Zr-rich phases generated by the peritectic reaction, the increased constitutional undercooling caused by Y addition and serve as surfactant led to the grain refinement. Besides, The average size of eutectic Si reduced from 8.5 μm in the base alloy to 6.2, 1.3, and 1.7 μm with the addition of Zr/Y/Zr + Y, respectively. Zr can slightly refine eutectic Si due to the limited growth space caused by grain refinement, while Y can modify the morphology of eutectic Si from plate-like into fibrous-like through high density twins formed by the IIT mechanism. The optimal mechanical properties are obtained when Zr and Y are added simultaneously with the ultimate tensile strength, yield strength, and elongation values of 104 MPa, 201 MPa, and 7.6%, respectively. The YS and UTS increase was due to grain-refining, Si modification and precipitation strengthening. The enhancement of El was mainly caused by Si modification, which reduced the possibility of crack initiation and propagation at Si/α-Al interfaces.

Interpenetrating polymer networks of polyurethane and polytriazole: Effect of the composition and number average molecular weight of glycidyl azide polymer on the mechanical properties and morphology

AbstractOn account of some special advantages of interpenetrating polymer networks (IPNs), the preparation of IPNs with excellent properties may be a promising way to strengthen the polyurethanes (PUs) and toughen the glycidyl azide polymer (GAP) based polytriazoles (PTAs). This work provides the effect of composition and number average molecular weight (Mn) of GAP on the mechanical properties and morphology of full‐IPNs. A series of IPNs based on the crosslinked Ace‐terminated GAP (Ace‐GAP) as polytriazole phase and crosslinked hydroxy‐terminated liquid fluorinated polymer (HTLF‐1500) as polyurethane phase (namely, GAP‐HTLF‐X full‐IPNs) were successfully fabricated via in situ polymerization without any catalysts at 80°C by azide–alkynyl click chemistry and hydroxyl‐isocyanate urethane reaction. These IPNs were characterized using attenuated total reflectance/Fourier‐transform infrared spectroscopy (ATR/FTIR), uniaxial tensile testing, swelling measurement, and scanning electron microscopy (SEM). The tensile strength of GAP‐HTLF full‐IPNs gradually increased by increasing the weight ratio of Ace‐GAP, but the breaking elongation dramatically decreased compared with elongation at break of HTLF polyurethane. In addition, a small Mn of GAP is beneficial in enhancing the tensile strength, elongation at break and toughness of the IPNs. However, a small Mn of GAP corresponds to increased difficulty of preparing GAP‐HTLF full‐IPNs. GAP1k‐HTLF full‐IPN was not successfully prepared. When the Mn of GAP was 2000 g/mol, the GAP2k‐HTLF‐80 full‐IPN exhibited prominent mechanical performance with a tensile strength of 83.1 MPa, elongation at break of 28.5% and fracture energy of 99.1 kJ/m3. Swelling measurement showed that when the weight ratio of GAP with larger Mn (5, 3, and 2 k) increased to more than 70%, the molecular interpenetration existed in the IPNs, demonstrating the presence of additional physical crosslinks and entanglement for full‐IPNs. SEM studies revealed that highly formed interpenetration and few microphase separations can be observed on the fracture surface of the IPNs with optimal mechanical properties. Combined with the results of mechanical properties, swelling measurement, and SEM studies, the degree of molecular interpenetration and microphase separation were beneficial to improve the mechanical properties of elastomers. This work can provide a certain guiding significance for the preparation of IPN with excellent properties.

Facile purification of glass fiber powder by sedimentation for enhanced epoxy resin composites

Glass fiber powder contains two distinct forms: crumb-shaped and rod-shaped glass fiber powder particles. The shape and size of the particles in glass fiber powder have a great influence on its application. In order to separate rod-shaped glass fiber, the effects of different dispersants, such as SHMP, NaOL, and Na2SiO3 on them were investigated by settling experiments. Zeta potential, X-ray photoelectron spectroscopy (XPS), optical microscope, and other methods were used to analyze the adsorption behavior and settling mechanism. Three-point bending experiment and dynamic mechanical analysis (DMA) were used to evaluate the performance of epoxy resin composites reinforced with the raw glass fiber powder and the rod-shaped glass fiber powder. The results show that SHMP can effectively separate crumb-shaped glass fiber powder and rod-shaped glass fiber powder, leading to a notable increase in sedimentation recovery difference, up to Δ=51.08%. A preferential sedimentation separation mechanism is proposed to elucidate the settling mechanism. When the content of glass fiber powder and rod-shaped glass fiber is 5%, the glass transition temperature shifts significantly towards higher values, leading to the optimum comprehensive mechanical properties of the composites. Compared with the original epoxy resin, the flexural strength increased by 10.38% to 95.18MPa and by 20.11% to 103.57MPa. Similarly, the storage modulus increased by 14.14% to 2083MPa and by 21.64% to 2220MPa.

Double-skeleton interpenetrating network-structured alkaline solid-state electrolyte enables flexible zinc-air batteries with enhanced power density and long-term cycle life

The alkaline solid-state electrolytes have received widespread attention for their good safety and electrochemical stability. However, they still suffer from low conductivity and poor mechanical properties. Herein, we report the synthesis of double-network featured hydroxide-conductive membranes fabricated by polyvinyl alcohol (PVA) and chitosan (CS) as the double-skeletons. Then, we implanted quaternary ammonium salt guar hydroxypropyltrimonium chloride (GG) as the OH− conductor for high-performance electrochemical devices. By virtue of the unique stripe-like structure shared from the double skeleton with a high degree of compatibility and stronger hydrogen bond interactions, the polyvinyl alcohol/chitosan-guar hydroxypropyltrimonium chloride (PCG) solid-state electrolytes achieved optimal thermal stability (>300 °C), mechanical property (∼34.15 MPa), dimensional stability (at any bending angle), and high ionic conductivity (13 mS cm−1) and ion mobility number (tion ∼ 0.90) compared with chitosan-guar hydroxypropyltrimonium chloride (CG) and polyvinyl alcohol-guar hydroxypropyltrimonium chloride (PG) electrolyte membrane. As a proof-of-concept application, the “sandwich”-type zinc-air battery (ZAB) assembled using PCG membrane as the electrolyte realized a high open-circuit voltage (1.39 V) and an excellent power density (128 mW cm−2). Notably, in addition to its long-term cycle life (30 h, 2 mA cm−2) and stable discharge plateau (12 h, 5 mA cm−2), it could even enable a flexible ZAB (F-ZAB) to readily power light-emitting diodes (LED) at any bending angle. These merits afford the PCG membrane a promising electrolyte for improving the performance of solid-state batteries.

Designing the heat treatment process for Mg-10Gd-4Y-xZn-0.6Zr (wt.%) alloy: A study on the transformation of microstructure and properties

Heat treatment of Mg10Gd-4Y-xZn-0.6Zr (x = 0, 1, 2 wt%) alloys has been optimized based on thermodynamic calculations and experiments. The phase transformations during the heat treatment and their effect on the mechanical properties of the alloys were discussed. Using thermodynamic calculations, three solution treatment temperatures of 475 °C, 500 °C, and 525 °C were determined, and the phase transformation under these temperatures were calculated and characterized, the results aligned well with experimental results. The optimal solution treatment technology was determined to be 500 °C for 18 h. After solution treatment, experimental alloys were subject to isothermal aging at 225 °C, the peak aging time for the experimental alloys was established. The microstructure under peak-aged state of the alloy was characterized, revealing a co-existed β’ and β1 phases. The GWZ1041K alloy, after peak aging treatment, exhibited optimal mechanical properties, with a tensile strength, yield strength, and elongation of 392.3 MPa, 249.3 MPa, and 5.7%, respectively. The study further analyzed the reasons for the microstructure transformation during the heat treatment and their influence on mechanical properties.

Injection Molding Condition Effects on the Mechanical Properties of Coconut-Wood-Powder-Based Polymer Composite.

This study investigates the mechanical properties of coconut sawdust powder combined with polypropylene (PP). The effect of compatibility content, wood powder (WP) content, and injection molding parameters on the properties of coconut wood powder composite (WPC) is evaluated. The results could be used to figure out the optimal mechanical properties such as tensile strength, elongation, elastic modulus, and flexural strength by selecting suitable parameters and composition. The bonding between the WP particles and the PP matrix is good, and the WP is uniformly distributed across the composite matrix, as indicated in the scanning electron microscopy (SEM) results. Interestingly, with the presence of the compatibilizer oleamide, increasing the WP content from 20 wt.% to 40 wt.% did not result in WP accumulation in the composite matrix. Notably, at 20 wt.% WP, the elongation is the highest (at 7.40 wt.%), while at 30 wt.% WP, the elastic modulus reaches the highest value. The maximum ultimate tensile strength (UTS) value is obtained at 35 wt.% WP. Higher WP mostly results in greater flexural strength and shore D hardness. At 40 wt.% WP, the WPC achieves its peak shore D hardness of 77.6. The Taguchi results suggest that WP content is the most critical factor in the UTS value of coconut WPCs. The filling pressure ranks second, followed by the packing pressure. Finally, unlike the other characteristics, the melt temperature has a minimal impact on the UTS value.

Recovery and reuse of magnetic silica-coated iron oxide particles for eco-friendly chemical mechanical planarization

Chemical mechanical planarization (CMP), a crucial process in semiconductor manufacturing, raises environmental concerns due to increased waste generation, prompting questions about its long-term sustainability. To address this issue, we explore an innovative approach to the waste management and recycling process by introducing magnetite (Fe3O4) particles coated with SiO2 layers, aimed at enhancing the CMP recycling efficiency. These core-shell particles exhibit controlled shell thickness, and modified surface charges, as confirmed by various analytical techniques. Our results reveal that slurries containing Fe3O4@SiO2 particles significantly improve W removal rates and surface smoothness compared to conventional slurries, attributed to the optimal mechanical properties. Moreover, the magnetite core facilitates the magnetic separation and recovery of used particles from spent slurries, offering a cost-effective and environmentally friendly solution. The recycling efficacy of these particles is demonstrated through multiple CMP cycles, showing consistent removal rates and surface quality, highlighting the potential of magnetic separation in sustainable CMP.