Thermo-mechanical performance, surface characteristics and life cycle assessment of tartaric acid treated kenaf fibers

The use of naturally derived eco-friendly biocomposites became more popular due to growing environmental concerns and hunt for sustainable materials. Biocomposites can reduce the residual waste and carbon emission to the environment during their lifecycle. The present study aims to develop biocomposites by reinforcing flax fiber (F) and kenaf fiber (K) laminates with bio-epoxy matrix at four different arrangements (FFF, FKF, KFK, and KKK). The biocomposite samples were fabricated with three laminated thicknesses (3 mm, 4 mm and 5 mm) and the thermo-mechanical performance was investigated. The results showed that FFF biocomposites recorded higher tensile, flexural, and interfacial properties with lower density and absorption of water compared to KKK biocomposites due to higher cylindrical lumen diameter of flax laminates. The hybridization of flax with kenaf fiber at different stacking sequences provided greater strength, modulus, toughness, stiffness, thermal stability and degradation behaviour due to greater interfacial interaction between laminated fiber and bio-epoxy. The FKF biocomposites showed maximum impact strength (52.96 kJ/m2), tensile strength (110.21 MPa), and compressive strength (139.64 MPa) at 5 mm laminated thickness while, flexural (158.67 MPa) and shear strength (39.45 MPa) were maximum at 4 mm thickness with the highest degradation temperature (336 °C). The optimal biocomposite configuration has been identified through employability of a novel decision-making framework encompassing interval-valued intuitionistic fuzzy sets, TOmada de DecisaoInterativaMulticriterio (TODIM) and Schweizer–Sklar operations. The inclusive evaluation with regard to the applied framework has revealed that FKF and KFK biocomposites with 4 mm thickness (Lam5 and Lam8) configuration to have the optimal configuration. On the other hand, Lam 10, i.e., KKK_3 mm turned out to be inferior to all the considered biocomposite configurations.

The use of kenaf fiber as a reinforcement material for polymer composites is gaining popularity, especially in the production of automotive components. The main objective of this current work is to relate the effect of alkali treatment on the single fiber itself and the composite material simultaneously. The effect of temperature condition during mechanical testing is also investigated. Composite materials with discontinuous natural kenaf fibers and epoxy resin were fabricated using a compression moulding process. The epoxy composites were reinforced with 50 wt% untreated and treated kenaf fibers. The kenaf fiber was treated with NaOH solution (6% by weight) for 24 h at room temperature. Kenaf fiber treated with NaOH treatment had a clean surface and no impurities. For the first time we can see that alkali treatment had a damaging effect on the mechanical properties of kenaf fibers itself and the treated kenaf/epoxy composites. The composite reinforced with untreated kenaf fiber and treated kenaf fiber showed increased tensile strength (72.85% and 12.97%, respectively) compared to the neat epoxy. Reinforcement of the composite with treated kenaf fiber decreased the tensile strength due to the fiber pull out and the formation of voids which weakens the adhesion between the fibers and matrix. The temperature conditions also play an important role in composites with a significant impact on the deterioration of composite materials. Treated kenaf fiber has thermal stability and is not sensitive to temperature and as a result reinforcement with treated kenaf gives a lower loss value of 76%.

Spectra investigation on surface characteristics of graphene oxide nanosheets treated with tartaric, malic and oxalic acids

Today natural fiber polymer composites are being extensively used as alternatives in producing furniture to fulfill society demand instead of saving cost and environmentally friendly. The objective of this search is to investigate the untreated fine and rough kenaf fiber (KF) as well as treated KF reinforced with polypropylene (PP) on the flexural strength. Flexural strengths of pure PP, 10%, and 20% of untreated fine and rough KF by weight to PP have been recorded. In addition, flexural strengths of treated KF soaked with 5% and 10% of Sodium Hydroxide (NaOH) have also been recorded. KF reinforced PP (PP/KF) untreated and treated composites were melt blended and then injection molded to observe their flexural strengths by measuring their threshold. Three point bending test was apply to determine the flexural stress of the composites. The result show treated fine KF produce better flexural performance at 20% PP/KF. Scanning Electron Microscopy (SEM) is used to observe the morphological surface PP/KF. Overall 5% NaOH with 20% PP/KF (Fine KF) show good interfacial bonding PP/KF and best result with flexural stress value 30.25MPa.Today natural fiber polymer composites are being extensively used as alternatives in producing furniture to fulfill society demand instead of saving cost and environmentally friendly. The objective of this search is to investigate the untreated fine and rough kenaf fiber (KF) as well as treated KF reinforced with polypropylene (PP) on the flexural strength. Flexural strengths of pure PP, 10%, and 20% of untreated fine and rough KF by weight to PP have been recorded. In addition, flexural strengths of treated KF soaked with 5% and 10% of Sodium Hydroxide (NaOH) have also been recorded. KF reinforced PP (PP/KF) untreated and treated composites were melt blended and then injection molded to observe their flexural strengths by measuring their threshold. Three point bending test was apply to determine the flexural stress of the composites. The result show treated fine KF produce better flexural performance at 20% PP/KF. Scanning Electron Microscopy (SEM) is used to observe the morphological surface PP/KF. Over...

Performance of two distinct fuel systems, U-7Mo fuel in Zircaloy (Zry-4) cladding and U-10Mo fuel in aluminum (Al6061-O) cladding was studied. First, a mini plate with Zry-4 cladding from a previous irradiation experiment was evaluated via finite element analysis (FEA). By using the same plate geometry and irradiation conditions, another plate consisting of U-10Mo fuel and Al6061-O cladding was simulated. The results were then comparatively evaluated to explore the feasibility of employing Zry-4 as an alternative cladding. Simulations indicated the Zircaloy cladding plate would operate roughly 50 °C hotter as compared with the Al alloy cladding plate. Larger deformations in the thickness direction for the plate with Zry cladding were noted. It was observed that the postfabrication stresses in the fuel would be relieved quickly in the reactor, regardless of cladding type. Although the fuel stresses would still develop at reactor shutdown, the fuel would be stress-free during the entire irradiation period for both cladding types. At shutdown, the plate with Zry cladding would have higher stresses due to higher operating temperatures. Similarly, the stresses after shutdown are higher in the foil core for the plates with Zry cladding. The Al cladding plate would have higher plastic strains as compared with the Zry cladding plate. The Zry cladding plate is significantly stiffer, causing higher stresses in the fuel zone and at the interface. Overall, employing Zry as an alternate cladding is not expected to produce a more favorable thermomechanical performance as compared to the performance of an Al alloy cladding plate.

Monolithic plate-type fuel is a fuel form that is being developed for the conversion of high performance research and test reactors to low-enrichment uranium fuels. These fuel-plates are comprised of a high density, low enrichment, U-Mo alloy based fuel foil encapsulated in an aluminum cladding. To benchmark this new design, number of plates has been irradiated with satisfactory performance. As a part of continuing evaluation efforts, a set of plates covering range of operational parameters is scheduled to be tested during MP-1 irradiation experiments. It is necessary to evaluate the thermo-mechanical performance of plates during irradiation. For this, selected plates with distinct operational histories; covering low power, high power and high fission density were simulated. Fully coupled three-dimensional models of plates with a capability to evolve mechanical and thermal properties of constituent materials with irradiation time and burn-up were developed. The models input used projected parameters, including plate geometry, irradiation history and coolant conditions as input. The model output included temperature, displacement and stresses in the fuel, cladding and diffusion barrier. The fuel behavioral model considered inelastic behavior including volumetric swelling due to solid and gaseous products, irradiation induced creep, thermal expansion, conductivity degradation and plasticity. A visco-plastic behavioral model was used for the cladding that included thermal creep, irradiation hardening, growth due to fast neutrons and Mises plasticity. The plates were then simulated by using projected irradiation parameters. The resulting temperature, displacement and stress-strains were comparatively evaluated on the selected paths. The results were then compared with those of plates from previous RERTR experiments.

Monolithic plate-type fuel is a fuel form that is being developed for the conversion of high performance research and test reactors to low-enrichment uranium fuels. These fuel-plates are comprised of a high density, low enrichment, U-Mo alloy based fuel foil encapsulated in an aluminum cladding. To benchmark this new design, number of plates has been irradiated with satisfactory performance. As a part of continuing evaluation efforts, a set of plates covering range of operational parameters is scheduled to be tested during MP-1 irradiation experiments. It is necessary to evaluate the thermo-mechanical performance of plates during irradiation. For this, selected plates with distinct operational histories; covering low power, high power and high fission density were simulated. Fully coupled three-dimensional models of plates with a capability to evolve mechanical and thermal properties of constituent materials with irradiation time and burn-up were developed. The models input used projected parameters, including plate geometry, irradiation history and coolant conditions as input. The model output included temperature, displacement and stresses in the fuel, cladding and diffusion barrier. The fuel behavioral model considered inelastic behavior including volumetric swelling due to solid and gaseous products, irradiation induced creep, thermal expansion, conductivity degradation and plasticity. A visco-plastic behavioral model was used for the cladding that included thermal creep, irradiation hardening, growth due to fast neutrons and Mises plasticity. The plates were then simulated by using projected irradiation parameters. The resulting temperature, displacement and stress-strains were comparatively evaluated on the selected paths. The results were then compared with those of plates from previous RERTR experiments.

The physico-mechanical properties of lignocellulosic kenaf fiber reinforced polyvinyl alcohol (PVA) biocomposite films were investigated. To improve the properties of the biocomposite, kenaf fibers were chemically treated separately in a single stage (with Cr2(SO4)312(H2O)) and double stages (with CrSO4 and NaHCO3) to improve the adhesion and compatibility between the kenaf fiber and PVA matrix. PVA was reinforced with various compositions of chemically treated kenaf fiber by using a solution casting technique. Microstructural analyses and mechanical tests were subsequently conducted. Scanning electron microscopic analysis indicated that chemical treatment improved the uniformity distribution of kenaf fiber within the PVA matrix. FTIR and XRD analyses confirmed the presence of chromium on the fiber surface. The tensile strength of PVA reinforced with chemical treated kenaf fiber was found to be higher than those reinforced with untreated kenaf. The Young’s modulus, flexural strength, and flexural modulus increased with fiber loading for both untreated and treated kenaf fiber reinforced PVA films. The double stage treated kenaf fiber showed better mechanical properties and lower moisture uptake than the single stage treated kenaf fiber.

This comprehensive study investigates the reinforcement of Lightweight Foamed Concrete (LFC) with 15 kg/m3 of untreated and treated Kenaf Fiber (KF) to improve its strength properties. Three different mix designs including control mix (LFC-CTR), LFC with untreated kenaf fiber (LFC-15UKF), and LFC with treated kenaf fiber (LFC-15TKF) were inspected to determine their strength properties including compressive strength, splitting tensile strength and flexural strength. The incorporation of KF with a length of 3 ± 1 cm did not significantly improve the compressive strength of LFC in both untreated and treated kenaf fiber condition. However, LFC-15TKF demonstrated the highest splitting tensile strength of 0.68 MPa. Identically, LFC-15TKF also exhibited the highest flexural strength at 2.52 MPa, attributed to the improved mechanical interlocking facilitated by the improved surface characteristics of treated KF. Scanning Electron Microscopy analysis revealed enhanced interfacial bonding in LFC-15TKF, emphasizing the role of the treatment purification process in promoting fiber surface adhesion with cement paste at Interfacial Transition Zone within the LFC matrix. Overall, despite a decrease in compressive strength compared to LFC-CTR, LFC-15UKF and LFC-15TKF demonstrated notable improvements in splitting tensile strength and flexural strength, indicating the effectiveness of KF in distributing and withstanding tension within LFC matrix.

Exhaust manifold of an IC engine typically experiences cyclic thermal and mechanical loading and are prone to TMF failure. Thermo-mechanical fatigue resistance needs to be ensured for exhaust manifold to meet the requirement of durability in order to meet the demanding needs of recent trends in IC engine design. Considering reduced product development cycle time, more accurate design procedure for exhaust manifold through simulation route is preferred. The present work is an attempt in this direction, where methodology to carry out TMF analysis of exhaust manifold through simulation is formulated and successfully implemented. The complete simulation process involved four important stages, namely simplified 1-D simulation of engine, thermal analysis of exhaust manifold, and structural analysis of exhaust manifold and TMF life evaluation of exhaust manifold. The developed methodology has been successfully implemented considering a typical exhaust manifold. Thermal inputs obtained through simplified engine simulation using 1-D gas dynamics and engine simulation software required for thermal analysis of exhaust manifold are found to be satisfactory and has eliminated the need for complex 3-D CFD simulations. TMF life valuated at critical locations indicate that except one location all other locations have life exceeding the LCF limit.

Thermomechanical fatigue (TMF) behavior of tin-based solder joints depends on several material-, process-, and service-related parameters. Although several focused studies have been conducted on such solder joints, incorporation of the roles of the above parameters and their relative importance for a comprehensive assessment of TMF behavior has not materialized so far due to the complexities involved. This paper suggests a simple parametric approach for the lifetime/reliability prediction of Sn-based solder joints incorporating findings from studies related to material and service issues.

Impact of modified kenaf fibers on shrinkage and cracking of cement pastes

Comparison of mechanical and interfacial properties of kenaf fiber before and after rice-washed water treatment

This study investigates the thermal behavior and thermo-mechanical properties of banana, jute, and kenaf fiber-reinforced epoxy composites, focusing on the impact of different layering sequences and hybrid configurations. The novelty of the work lies in the tailored stacking of natural fibers to optimize composite performance, a topic of growing significance in sustainable engineering. Thermal analysis revealed the highest endothermic peak at 72 °C in BJKKJBE hybrid composites, while jute fiber-reinforced composites exhibited a marginally higher peak at 73 °C. Dynamic mechanical analysis highlighted kenaf fiber-reinforced composites as having superior storage modulus values, reaching 152 MPa at 10 Hz, followed by the BJKKJBE hybrid, which achieved 137 MPa. Additionally, banana fiber-reinforced composites and neat epoxy recorded the highest loss modulus values (52 MPa and 51 MPa), indicating excellent energy dissipation. Neat epoxy and kenaf fiber reinforced composites displayed the highest tan delta values, with BJKKJBE hybrids also showing notable damping behavior, suggesting effective vibration attenuation. On the other hand, jute-based composites demonstrated the lowest tan delta, reflecting increased stiffness. A significant outcome is the thermal expansion behavior, where BJKKJBE composites exhibited the highest shrinkage (0.3%), while the KBJJBKE reinforcement, with kenaf as a skin layer, recorded the highest coefficient of thermal expansion (257 ppm °C−1). These findings present new opportunities for optimizing fiber-reinforced epoxy composites in applications requiring tailored thermal and thermo-mechanical performance, contributing to advancements in sustainable materials design for engineering applications.

Natural fibers and fillers are playing a predominant role in enlightening the damping and mechanical properties of polymer material. The hybrid kenaf polymer composite was prepared using compression molding technique with the micrometric sized Prunus amygdalus fillers of 0, 5, 10, and 15 vol%, evenly distributed in the vinyl ester polymer interlayers. This work deals with the effect of variation in P. amygdalus content and the effect of chemical treatments like silane and alkaline treatment on the dynamic characteristics of fabricated composites. The kenaf woven fabric and P. amygdalus fillers were chemically treated using tri vinyl ethoxy silane and sodium hydroxide (NaOH) solution to modify their surface characteristics. The effect of chemical treatment on the kenaf fiber and P. amygdalus filler was characterized using Fourier transform infrared spectroscopy. From experiments, it is observed that chemical treatment removes the strength reducing substances like lignin, hemicellulose and wax from the kenaf fiber and P. amygdalus filler surfaces. The addition of filler and chemical treatment increase the tensile strength to 56 MPa and flexural strength to 89 MPa. Silane‐treated P. amygdalus filler with 10% composite, reveals higher storage modulus of 4.71 GPa than the alkaline and untreated composites in all tested frequencies. This may be due to enhanced tensile modulus and better interfacial bonding between P. amygdalus filler and vinyl ester matrix. Fractography was studied using micrographs of the scanning electron microscope. The result shows the predominance of brittle mode of failure in all types of fabricated composites. This kind of industrial agro waste hybrid composite can be considered as an effective damping material.