Properties Of Composites Research Articles

Investigation of Chemical Composition, Antioxidant Properties, and Molecular Docking in Different Roasting Stages of Coffee Beans

AbstractThis study investigates the chemical composition and antioxidant properties of coffee beans at different roasting stages, namely green coffee, filter-roasted coffee, and espresso-roasted coffee. Using a Golden Roaster machine, specific roasting profiles were developed to achieve distinct flavor characteristics: an intense flavor and balanced acidity for espresso, and a balanced, complex taste for filter coffee. Results indicate that filter-roasted coffee exhibits the highest radical scavenging activity, as evidenced by its lowest IC50 value for 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition. Green coffee demonstrates superior iron chelation activity, while filter-roasted coffee contains the highest flavonol content and espresso-roasted coffee has the highest flavonoid content. Bacterial sensitivity tests show that both filter-roasted and espresso-roasted coffee are effective against certain strains, including Klebsiella pneumoniae ATCC 13883. Gas chromatography-mass spectrometry (GC–MS) analysis identifies key compounds such as caffeine and 4,4-dimethyl-3-(3-methylbut-3-enylidene)-2-methylenebicyclo [4.1.0] heptane in filter-roasted coffee, and 2-(2-hydroxyphenyl) buta-1,3-diene in espresso-roasted coffee. Molecular docking and in silico molecule’s absorption, distribution, metabolism, excretion, and toxicity (ADME) studies suggest potential pharmaceutical applications for coffee compounds. These findings provide valuable insights into coffee’s complex chemistry and its health-related properties. Additionally, the importance of coffee profiling in bioprocesses is highlighted by the need to carefully analyze the profiling process to optimize the biological effects and health benefits of these compounds. Coffee profiling not only enhances consumer taste experiences but also contributes to a better understanding of coffee’s potential health benefits by effectively identifying biomolecules and nutrients for use in bioprocesses. Graphical Abstract

Interface modification strategy to construct SiC nanowires@pyrolytic carbon reinforcement for carbon fiber composites

AbstractDesigning and optimizing the interface of carbon fiber composites is the key to improve mechanical and biotribological properties. Carbon fiber‐reinforced hydroxyapatite‐epoxy matrix (CM) composites, which have excellent mechanical and biotribological properties, are often used to avoid artificial bone damage and improve the longevity of artificial bone. In this work, a SiC nanowires@pyrolytic carbon (SiCnws@PyC) is designed and incorporated into the CM to improve the mechanical and biotribological properties. SiCnws@PyC can promote bonding of the fiber/matrix interface and cohesion of the epoxy matrix. The mechanical and biotribological properties of CM are greatly improved because of the interface modification and reinforcement of SiCnws@PyC. The tensile strength and elastic modulus of SiCnws@PyC‐reinforced CM are 18.73% and 38.71% higher than those of CM, respectively. SiCnws@PyC‐reinforced CM has a 9.09% reduction in the friction coefficient and a 74.61% reduction in the wear rate. This study provides a promising methodology for the preparation of SiCnws@PyC‐reinforced CM with better stability and longevity for bone grafting applications.Highlights The mechanism of SiC nanowires@pyrolytic carbon (SiCnws@PyC) is explained. The SiCnws@PyC structure is designed into composites. PyC core‐shell transforms the structure of hydroxyapatite. The SiCnws@PyC enhances mechanical and biotribological properties of composites.

StackedEnC-AOP: prediction of antioxidant proteins using transform evolutionary and sequential features based multi-scale vector with stacked ensemble learning

BackgroundAntioxidant proteins are involved in several biological processes and can protect DNA and cells from the damage of free radicals. These proteins regulate the body's oxidative stress and perform a significant role in many antioxidant-based drugs. The current invitro-based medications are costly, time-consuming, and unable to efficiently screen and identify the targeted motif of antioxidant proteins.MethodsIn this model, we proposed an accurate prediction method to discriminate antioxidant proteins namely StackedEnC-AOP. The training sequences are formulation encoded via incorporating a discrete wavelet transform (DWT) into the evolutionary matrix to decompose the PSSM-based images via two levels of DWT to form a Pseudo position-specific scoring matrix (PsePSSM-DWT) based embedded vector. Additionally, the Evolutionary difference formula and composite physiochemical properties methods are also employed to collect the structural and sequential descriptors. Then the combined vector of sequential features, evolutionary descriptors, and physiochemical properties is produced to cover the flaws of individual encoding schemes. To reduce the computational cost of the combined features vector, the optimal features are chosen using Minimum redundancy and maximum relevance (mRMR). The optimal feature vector is trained using a stacking-based ensemble meta-model.ResultsOur developed StackedEnC-AOP method reported a prediction accuracy of 98.40% and an AUC of 0.99 via training sequences. To evaluate model validation, the StackedEnC-AOP training model using an independent set achieved an accuracy of 96.92% and an AUC of 0.98.ConclusionOur proposed StackedEnC-AOP strategy performed significantly better than current computational models with a ~ 5% and ~ 3% improved accuracy via training and independent sets, respectively. The efficacy and consistency of our proposed StackedEnC-AOP make it a valuable tool for data scientists and can execute a key role in research academia and drug design.

Comparison of degree of conversion performance of bulk-fill resin composites: A systematic review and network meta-analysis of in vitro studies

ObjectivesTo systematically compile data on the degree of conversion (DC) for bulk-fill composites using a network meta-analysis. MethodsA systematic search for in vitro studies of DC of bulk-fill composites was performed in PubMed, Web of Science, Scopus, and Open Grey. Risk of bias within studies and due to missing evidence was assessed using the Joanna Briggs Institute scoring system and ROB-MEN tool, respectively. The primary outcome was the DC of bulk-fill composites. Surface Under the Cumulative Ranking curve (SUCRA) was used to rank relative performance. Inconsistencies in the model were investigated to ensure its validity and the level of confidence in the network meta-analysis (CINeMA) was assessed. ResultsA total of 28 studies were included in the quantitative analysis. The average DC values (%) for 0-h/top, 0-h/bottom, 24-h/top, and 24-h/bottom were 59.09, 57.14, 66.73, and 63.87, respectively. According to their SUCRA ranking, the best-performing composites were: SonicFill, Venus Bulk Fill, and SDR (0-h/top), Reveal HD, i-Flow Bulk Fill, and Venus Bulk- Fill (0-h/bottom), Venus Bulk Fill, SDR, and QuiXfil (24-h/top), and Venus Bulk Fill, Aura Bulk Fill, and i-Flow Bulk Fill (24-h/bottom). Incoherence between direct and indirect evidence was identified as the most significant factor affecting confidence. ConclusionsDC values of bulk-fill composites were within the range commonly reported for previous generations of “conventional” composites, with flowable composites tending to perform better than sculptable composites. High variability in DC data was observed, which may be attributed to incompletely understood methodological differences. Clinical significanceDC is a fundamental parameter that influences multiple mechanical and biological properties of resin composites and is particularly relevant for the group of bulk-fill composites that are designed for use in thick layers.

Effect of alternating magnetic field on microstructure and mechanical properties of Ni60/La2O3 laser cladding layer

A Ni60 cladding layer containing 1.6 wt% La2O3 was prepared on 35CrMoV steel using an alternating magnetic field-assisted laser cladding technique. The microstructure, phase composition, microhardness, and tribological properties of the composite coatings were characterized. Based on experimental results, the main components of the 1.6 % Ni60 + La2O3 cladding layer are γ-(Fe,Ni), Cr23C6, FeNiSi, Ni3B, Ni4B3 and Cr2B. The EBSD analysis reveals that the increase in intensity of the alternating magnetic field leads to a significant refinement in the average grain size of the cladding layer, thereby greatly enhancing microstructural uniformity. The average grain sizes of the layers with 0–15 mT magnetic field intensity are 28.515 μm, 26.076 μm, 23.878 μm and 18.337 μm, respectively. The TEM bright field images reveal that the enhancement of magnetic field intensity facilitates the precipitation of γ′ within the cladding layer. Friction and wear experiments demonstrated that a Ni60 composite coating containing 1.6 % La2O3 exhibited superior friction and wear performance at a magnetic field intensity of 15 mT due to its highest average hardness (608.97 HV1), lowest friction coefficient (0.394), and excellent wear morphology.

Effect of Filler Content and Treatment on Mechanical Properties of Polyamide Composites Reinforced with Short Carbon Fibres Grafted with Nano-SiO₂

Effect of Filler Content and Treatment on Mechanical Properties of Polyamide Composites Reinforced with Short Carbon Fibres Grafted with Nano-SiO₂

Thermal-Insulation Fillers’ Influences on the Heating Resistance of PDMS-Based Aerogel Layer

PDMS-based aerogel layers were synthesized as insulation layers by adopting mullite fiber (MF), hollow glass microspheres (HGM) and silica aerogel (SA) as the main fillers, and their loading amounts and content ratios were checked to investigate their effects on the thermal insulation properties in PDMS composites by thermal conductivity, thermal stability, and thermal insulation. The loading amount of nanofillers can significantly influence the insulation-layer performance, and the best performance with the lowest thermal conductivity of 0.0568 W/(m·K) was obtained by 10 wt% loading in PDMS with MF:SA:HGM = 2:2:1, which can achieve a temperature difference (∆T) of 67 °C on a 200 °C hotplate. Moreover, the variation of the filler content ratios can also affect the thermal insulation behavior when the loading amount is fixed at 10 wt%, and the best thermal barrier performance can be found for the sample with more SA as the filler (MF:SA:HGM = 1:3:1). The formed sample had the best thermal stability and thermal insulation property, which can stand a 9 min flame test without burning by butane spray gun, and the backside of the sample showed ∆T > 500 °C for the whole test.

Systematic investigation on the rational design and optimization of bi-based metal oxide semiconductors in photocatalytic applications

To address the global energy shortage and mitigate greenhouse gas emissions on a massive scale, it is critical to explore novel and efficient photocatalysts for the utilization of renewable resources. Bi-based metal oxide (Bi x MO y ) semiconductors composed of bismuth, transition metal, and oxygen atoms have demonstrated improved photocatalytic activity and product selectivity. The vast number of element combinations available for Bi x MO y materials provides a huge compositional space for the rational design and isolation of promising photocatalysts for specific applications. In this study, we have systematically investigated the electronic and optical properties over Bi2O3 and a series of selected Bi x MO y group materials (BiVO4, BiFeO3, BiCoO3, and BiCrO3) by calculating band structure, basic optical property features, mobility and separation of charge carriers. It is clearly noted that the band gap and band edge position of the Bi x MO y group materials can be tuned in a wide range in comparison to Bi2O3. Similarly, the light response of Bi x MO y also can be broadened from the ultraviolet to the visible light region by adjusting the selection of transition metals. Additionally, the analysis of the effective mass of charge carriers of these materials further confirms their possibility in photocatalytic reaction applications because of the appropriate separation efficiency and mobility of carriers. A selection of experimental investigations on the crystal structure, composition, and optical properties of Bi2O3, BiVO4, and BiFeO3 as well as their catalytic performance in the degradation of methylene blue over was also conducted, which agree well with the theoretical predictions.

Influence of Graphite and Zirconia Addition on the Tribological Properties of Plasma-Sprayed Alumina Coatings

Al2O3, Al2O3-graphite and Al2O3-ZrO2 coatings were formed on the C45 steel rolls using atmospheric plasma spraying. The influence of graphite and zirconia addition on the surface morphology, phase composition and tribological properties under dry sliding conditions using 30 N load were analyzed. It was found that the addition of graphite or ZrO2 slightly affected the fraction of the α-Al2O3 and γ-Al2O3 phases in the alumina coatings. The highest mass loss rate (~8.84 × 10−4 g/s) was obtained for the friction pair of C45 steel roll and steel plate. The friction coefficient of the Al2O3-graphite coating was slightly lower (up to 7%) compared to the coating of Al2O3-ZrO2. However, the friction pair of Al2O3-ZrO2 coating and steel plate demonstrated the highest wear resistance under dry sliding conditions. The increase in the wear resistance of the Al2O3-graphite and Al2O3-ZrO2 coatings is due to the formation of tribofilm in the sliding contact zone.

Corrosion and corrosion-friction effects induced by cutting fluid on binderless WC matrix composite and cemented carbide

The corrosion behavior of WC-4.3wt.%MgO-2wt.%ZrO2 composite in alkaline solution with 5% oil-based cutting fluid as medium was studied by electrochemical and microstructure analysis methods. The results showed that WM2Z composite has better corrosion resistance than YG3 and YG6 in alkaline environment. A stable passivation film was formed inside the WC phase after dissolution on the surface, which was the key reason for its high corrosion resistance. However, large areas of WC phase fell off in cemented carbide. In the process of corrosion-friction coupling experiment, due to the more excellent corrosion resistance and mechanical properties of WM2Z composites, the corrosion resistance and friction properties of WM2Z composites are better than that of YG3 cemented carbide. The corrosion-friction coupling effect on WM2Z was low, and the degree of damage to the topography after the experiment was relatively light.

Investigation on the mechanical properties of wood-plastic composites for the application of ceiling panels

Wood-plastic composites are relatively novel composite materials that consist of a blend of wood flour waste with high-density polyethylene and polypropylene plastic waste, designed for use in ceiling applications. Various samples were produced using different ratios from the total weight, including 20:80, 30:70, and 40:60, with sieve sizes of 0.425 mm, 1.18 mm, and 2 mm. The composites were created by melting plastics and sawdust at a temperature of 1800c utilizing the hot-press moldings technique employing diverse formulations. The properties of sample composites were analyzed experimentally based on ASTM standards to investigate water absorption levels as well as flexural strength, impact resistance hardness along with surface morphology via the design of experiments. This research study indicates that nine composite formulations consisting of HDPE and PP plastics combined with wood flour can produce favorable physio-mechanical properties. Among these various combination specimens tested in this study FS3/FC30N exhibited excellent physio-mechanical properties; including desirable values such as water absorption level at 5.5103%, flexural strength at 61.12 Mpa, impact resistance measuring 33.45 J cm−2, and hardness rating up to 80 RHB. Thus it is highly recommended for use in chipboard ceiling panel applications due to its potential benefits.

Mechanical and thermal properties of glass fiber reinforced polymer-clay nanocomposites

Abstract The effect of Montmorillonite (MMT) nanoclay on static mechanical and thermal characteristcs of glass fiber-reinforced polymer (GFRP) composites is studied. The static tensile properties of epoxy/MMT nanoclay, which are important properties of GFRP composites, are investigated. The predicted stress-strain curves of epoxy with 0 and 1 wt.% of nanoclay follow experiments. The predicted elastic modulus and tensile strength of epoxy with 3 wt.% of nanoclay are 74 and 230% higher than neat epoxy. For GFRP composites with 0, 1, 3, and 5 wt.% of MMT nanoclays, the measured tensile strengths are 587, 600, 628, and 724 MPa, and flexural strengths are 626, 726, 906, and 542 MPa. For composites with former nanoclays, interlaminar shear strengths are 23, 25, 31, and 28 MPa, and Izod impact strengths are 83, 94, 207, and 145 kJ/m2. Thus, mechanical strengths of composites with 0–5 wt.% of nanoclays improve considerably than pristine sample. The predicted static tensile stress-strain curves of GFRP composites with above nanoclays follow experimental behavior. For GFRP composites with 0 and 1 wt.% of MMT nanoclays, glass transition temperatures are 91 and 101°C, and storage moduli at ambient temperature are 35 and 41 GPa. The thermal conductivities of GFRP composites with 0, 1, and 3 wt.% of MMT nanoclays at ambient temperature are 0.32, 0.36, and 0.42 W/(m·K). Thus, thermal properties of composites are affected significantly on addition of nanoclays.

Peanut (Arachis hypogaea L.) flour and oilcake flour: Exploring the influence of roasting and varietal differences on proximal composition, elemental profiling, antimicrobial and antioxidant properties

Peanuts are highly valued for their abundance of essential nutrients and health-promoting phenolic compounds. Peanut press cake, an inexpensive and underutilized agro-industrial by-product of oil production, is typically discarded or used as animal feed. This study investigated the influence of thermal processing and varietal disparities on the nutritional composition, phenolic content, and biological properties of peanut flour and oilcake flour, aiming to enhance their value as food ingredients. The findings showed that roasting significantly increased the oil (9.98 ± 0.11–44.13 ± 0.10 %), ash (1.28 ± 0.01–5.45 ± 0.05 %), carbohydrate contents (0.90 ± 0.01–28.09 ± 0.28 %), and energy value (406.69 ± 0.09–609.13 ± 1.08 kcal/100 g), along with the total polyphenol content (28.64 ± 0.19–62.79 ± 1.18 mg GAE/g), total flavonoid content (4.20 ± 0.07–18.35 ± 0.06 mg QE/g) and antioxidant activity in both peanut flour and its oilcake. Conversely, it led to a reduction in the moisture (1.48 ± 0.09–6.25 ± 0.15 %) and protein content (49.50 ± 0.05–54.24 ± 0.01 %). Notable variations were found between the two peanut varieties in terms of these nutritional parameters. Elemental analysis unveiled significant discrepancies among peanut varieties and with roasting, with potassium (12,237.56 ± 101.36–14,513.34 ± 168.62 mg/kg) emerging as the predominant macro-element followed by phosphorus (6156.86 ± 36.19–8815.22 ± 130.70 mg/kg) and magnesium (3037.92 ± 13.87–4096.44 ± 8.54 mg/kg), while zinc (53.98 ± 0.61–81.77 ± 0.44 mg/kg) predominated among the microelements. Moreover, peanut and oilcake flours demonstrated antibacterial activity against several bacteria. It can be inferred that roasted peanut and oilcake flours offer substantial nutritional value, making them promising candidates for addressing protein-energy malnutrition and serving as valuable ingredients in developing new food products.

Versatile fabrication of carbon nanotube yarn composites by in-situ interfacial polymerization of polyetherimide

Manufacturing of high-performance carbon nanotube (CNT)-based polymer composites has long been complicated by the difficulty of infiltrating the nanoporous network presented by continuous CNT materials; this can yield composites with heterogeneities that drastically worsen their mechanical properties. We show the synthesis of CNT-polyetherimide (PEI) composite yarns via in-situ interfacial polymerization (ISIP), which side-steps slow, viscous polymer transport by infiltrating and reacting monomer species in-situ via a rapid and scalable process. We demonstrate the ISIP technique on two distinct, industrially-produced CNT yarns, and identify processing parameters that achieve conformal polymer coatings, yielding statistically-significant increases to linear density-specific tensile properties. Using ISIP on pre-densified yarns results in composites with specific stiffness and tenacity of 142 N/tex and 2.2 N/tex, respectively. When ISIP is applied to lightly-processed, porous CNT yarn, the specific stiffness and tenacity reach up to 66 N/tex and 0.7 N/tex. The role of interfacial effects, particularly from amorphous carbon, on the composite properties is also explored. Finally, we demonstrate a prototype roll-to-roll ISIP apparatus which can process arbitrary lengths of yarn for continuous composite production.

Is mantle transition zone uniform beneath the Precambrian shields?

In the present study, we examine the mantle transition zone (MTZ) structure below the prominent Precambrian shields on the Earth to understand its thermal and compositional properties and depth distribution of MTZ discontinuities. For this study, we used data from Canadian, Brazilian, Baltic, African and Australian Shields. We migrate the receiver functions to the depth domain using 3D tomographic models to examine the topography of MTZ discontinuities that define the upper and lower MTZ layers. The depth migration results were obtained using two different 3D tomographic velocity models, LLNL_G3D_JPS and GyPSuM. The analysis shows that both models yield similar results. The findings indicate a thinner than usual MTZ beneath all the Precambrian shields with an average thickness of ∼ 238 ± 8 km. Notably, the present study reveals the upper boundary of the MTZ (410 km discontinuity) displays distinctive topography; in contrast, the lower boundary of the MTZ (660 km discontinuity) is situated at shallower depths. Therefore, the main factor causing the variation in MTZ thickness is the shallowing of the 660 km discontinuity, indicating that the post-spinel transition occurred at higher temperatures with a negative Clapeyron slope, supporting the theory of whole-mantle convection. This suggests that mantle plumes have some appreciable impact on the MTZ beneath Precambrian shields, which are limited to the base of the upper mantle. Alternatively, the global mantle warming explanation could be invoked, as it best explains the similar characteristics of the 660 km discontinuity beneath the Precambrian shield. However, this phenomenon needs to be tested through numerical modelling.

Mechanical properties of cement-based composites incorporating eco-friendly aggregate of waste rubber

The purpose of this study is to evaluate the waste tires that harm the environment as aggregate in concrete and to examine the effect on the mechanical properties of concrete. Three different classes (powder, crumb and chips) of waste rubber with seven different ratios (0%, 4%, 8%, 12%, 16%, 20% and 24%) and two different water to cement ratio (0.4 and 0.5) were used in concrete production. In this regard, this study conducted various experiments consisting of 28 and 90 days of the curing process to determine the properties of unit weight, compressive, flexural, and splitting tensile strength, along with ultrasonic pulse velocity (UPV) and dynamic modulus of elasticity. The waste rubber concrete with the highest compressive strength at the end of 90 days is the concrete that includes 4% waste rubber (0.4WR4) with 58.81 MPa. Concrete containing 8% waste rubber has the highest UPV of 5660 m/s after 90 days. The increase in the water/cement ratio from 0.4 to 0.5 and the waste rubber ratio cause deterioration in the mechanical properties of concrete. Although the use of waste rubbers does not bring an increase in strength, it is feasible to produce high strength concretes with 4% and 8% waste rubber substitution ratios. The water/cement ratio and curing time were highly effective on the mechanical properties of rubberized concrete.

Synergistic effect of YAG particulate reinforcement on microstructural and thermo-mechanical properties of pressureless sintered MgAl2O4 spinel ceramic composites

Yttrium aluminum garnet (YAG) powders, synthesized through a partial wet chemical process, exhibit controlled morphology, high phase purity, and uniform homogeneity etc. This process involves the precipitation of aluminum ions onto Y2O3 particles. The transformation process of the Al-compound/Y2O3 precursor structure leads to the direct crystallization of pure YAG at 900 °C, passing through an intermediate stage where hexagonal YAH phase forms. A comprehensive study was conducted on the impact of preformed YAG as a reinforcing phase on the densification, mechanical, and thermo-mechanical properties of MgAl2O4-YAG composite, sintered under pressureless sintering in temperature range of 1500 °C–1600 °C. The inclusion of YAG particulate up to 5.0 wt% significantly enhances the densification, hardness, fracture toughness, flexural strength and high-temperature mechanical behavior of magnesium aluminate spinel (MAS) ceramics, however, increasing the YAG content beyond 5.0 wt% causes a reduction in these properties. The optimized addition of YAG particulate contributes to reducing the average grain size and refining the microstructure of the spinel ceramic matrix.

Self-assembled Sm0.5Sr0.5CoO3-δ-Ce0.8Sm0.2O2-δ composite for solid oxide electrolysis cells

The anode is the key material that constrains the performance of solid oxide electrolysis cells (SOECs). Here, we have developed self-assembled Sm0.5Sr0.5CoO3-δ-Ce0.8Sm0.2O2-δ (SSC-SDC) composite by the co-synthesis strategy and studied its electrochemical performance as the anode for SOECs. The surface and interface properties of the self-assembled SSC-SDC composite were systematically studied. The SDC lattice expansion and the SSC lattice contraction of the SSC-SDC composite have been shown by XRD analysis, ascribed to the strong cation interdiffusion during the self-assembly process. The self-assembled SSC-SDC also exhibits superior oxygen evolution activity and displays a larger oxygen desorption peak than the physically mixed SSC&SDC. A higher proportion of adsorbed oxygen species on the surface of the self-assembled SSC-SDC than the physically mixed SSC&SDC also have been shown by XPS results. The cell with the self-assembled SSC-SDC as anode exhibits ca. 2.1 times higher current density than the physically mixed SSC&SDC as anode. Meanwhile, the polarization resistance of the cell with self-assembled SSC-SDC as the anode is 0.0957 Ω cm2, which is only 40 % of that observed in the cell where SSC and SDC are physically mixed as the anode. This novel self-assembly strategy shows great potential for preparing high-performance oxygen electrodes.

Effects of TiO2 nanobelts addition on microstructure and physical properties of vitrified bonds

Titanium dioxide (TiO2) is commonly used additive to improve the strength, hardness and coefficient of expansion properties of vitrified bonds. In this work, TiO2 nanobelts were prepared through hydrothermal method, and the effect of TiO2 nanobelts content on the microstructure and physical properties of vitrified bonds and vitrified bond CBN composites were systematically investigated. When the content of 0.2 wt% TiO2 nanobelts and sintered at 660°C, as-prepared nano-vitrified bonds exhibited the beneficial performance improvement. Specifically, the obtained coefficient of thermal expansion, flexural strength, microindentation hardness, and mobility are 5.37×10-6 °C-1, 85.96 MPa, 853.19 MPa, and 140.6 %, respectively. Moreover, the vitrified bonds with 0.2 wt% TiO2 nanobelts addition is further used to optimize the performance of cubic boron nitride (CBN) composites. When sintered at 720 °C, the CBN composite samples depicted the excellent flexural strength, rockwell, porosity, and grinding ratio of 63.27 MPa, 61.5 HRB, 48.9 %, and 22.3, respectively. It can be attributed to the positive contribution of nano-vitrified bonds on the physical properties of CBN composites. This work is expected to contribute to the research on improving the performance of vitrified bonds with nano additives, and further obtain excellent performance nano-vitrified bond materials for the design and manufacturing of high-performance superhard abrasive tools.

Novel polybenzoxazine-based arylidene moiety modified cellulose acetate for enhanced antifouling properties

Marine fouling is a widespread problem in the maritime industry, causing significant damage to equipment and vessels. Polybenzoxazine (PBz) is a resin that is both remarkable and captivating, and it has a wide range of sophisticated uses. Due to their distinctive characteristics, benzoxazines have sparked the interest of scholars globally. However, most benzoxazine resin production and processing depend on petroleum resources, particularly those based on bisphenol A. This study aimed to create new benzoxazine monomers using bio-based raw materials, primarily motivated by the environmental ramifications. The main goal of this study is to synthesize a benzoxazine molecule, specifically (2E,6E)-2,6-bis(3-(2-hydroxyethyl)-3,4-dihydro-2H-benzo[e][1,3]oxazin-6-yl)methylene) cyclohexane-1-one, abbreviated as (CHPE), by employing an arylidene base. Later, the chemical was used as a modifier for the cellulose acetate (CA) matrix to create film samples. The primary objective is to evaluate the effectiveness of these film samples in preventing fouling. The CHPE molecule was produced using a bis(arylidene) cyclohexanone diol and analyzed using Fourier transform infrared (FTIR) and Nuclear magnetic resonance (NMR) spectroscopic techniques, respectively. The films were fabricated by blending various weight proportions. The composition of the (CHPE-CA) films was determined by FTIR analysis, while their morphology was examined using scanning electron microscopy (SEM). The thermal stability of the films was studied using Thermal Gravimetric Analysis (TGA). This study investigated the antifouling properties of polymer sheet compositions containing varying amounts of CA at two different processing temperatures, 180 °C and 200 °C and without curing. The results demonstrated the potential of incorporating CA into the polymer matrix to enhance antifouling performance. Among the polymer compositions tested, the 20% CA composition exhibited the highest percentage reduction in fouling at both processing temperatures, suggesting that a small amount of CA can contribute to effective antifouling properties.