Epoxy Matrix Research Articles

Sustainable innovations: Mechanical and thermal stability in palm fiber-reinforced boron carbide epoxy composites

This study reports the development of a sustainable composite material by integrating boron carbide (B4C) nanoparticles into palm fruit fiber (PFF)-reinforced epoxy matrices. The mechanical and thermal properties of these composites were thoroughly assessed, yielding promising results across key performance metrics. Tensile strength increased to 41.73 MPa with 4 % B4C, while flexural strength reached 43.29 MPa at the same concentration. Impact energy also saw an improvement, peaking at 5.6 kJ/m² with 4 % B4C. Similarly, hardness values showed an upward trend, with a Shore D value of 73. Additionally, water absorption was reduced from 7.2 % to 5.3 %, indicating enhanced moisture resistance. Thermal analysis confirmed the superior thermal stability of the composite, as shown by Thermogravimetric Analysis (TGA) and Differential Thermogravimetry (DTG) curves, with the maximum mass loss occurring at a higher temperature for the 4 % B4C composite. Fatigue stress testing also demonstrated improved durability, with the 4 % and 5 % composites exhibiting higher fatigue resistance over multiple cycles. The findings suggest that a 4 % concentration of boron carbide achieves an optimal balance of improved mechanical strength, durability, and thermal stability, making these composites suitable for high-performance applications while promoting environmental sustainability.

Effects of oxidation‐induced aggregation structure transformation of aramid fiber on interfacial adhesion of epoxy resin

AbstractThe large‐scale pretreatment and efficient surface activation of aramid fibers (AFs) before composite fabrication remains a major challenge. In this study, we developed a heat treatment–induced surface modification method to change the reactive groups on AFs. Results indicated that the O/C ratio and the number of ester groups on the AFs as well as the surface morphology of the AFs could be flexibly controlled using the heat treatment–induced surface modification method. Furthermore, the surface oxidation mechanism of the AFs changed from point oxidation to surface oxidation during heat treatment. As the heat‐treatment time increased, the crystallinity and tensile strength of the AF monofilament considerably increased. An optimal heat‐treatment time of 30 min was provided considering that long‐time heating (>30 min) would destroy the surface molecular chains. Under this optimal heat‐treatment time, the number of ester groups reached the maximum, which enhanced the reactivity of the AFs in the epoxy resin matrix. The interfacial shear strength between the AFs treated for 30 min and epoxy resin microdroplet increased by 12.64%, reaching as high as 18.17 MPa. Moreover, the contact angle between the AF monofilament and epoxy resin droplet reached a minimum value of 54.7°. Furthermore, the thickness of the interfacial bond layer between the AFs and epoxy resin reached 50–60 nm. These results provide effective theoretical guidance for the large‐scale application of AFs in composite materials.

Effect of Drilling Parameters and Tool Diameter on Delamination and Thrust Force in the Drilling of High-Performance Glass/Epoxy Composites for Aerospace Structures with a New Design Drill.

Real service requirements of the assembly performance and joining properties of design components are critical for composite usage in the aerospace industry. This experimental study offers a novel and comprehensive analysis of dry drilling optimization for glass-reinforced, high-performance epoxy matrix composites used in aerospace structures, focusing on thrust force and delamination. The study presents a first-time investigation into the combined effects of spindle speed (1000, 2250, 4000 and 5750 rpm), feed rate (0.2, 0.4, 0.6 and 0.8 mm/rev) and tool diameter (3 and 5 mm) using a custom-designed drill tool specifically developed for this application, filling a gap in the current literature. By employing the Taguchi design of experiments, the study identified that medium spindle speeds (2250-4000 rpm), lower feed rates (0.2 mm/rev) and smaller tool diameters (3 mm) provided optimal conditions for minimizing thrust force and delamination. These results present actionable insights into improving the structural integrity and performance of drilled aerospace-grade composite components, offering innovative advancements in both the aerospace and defense industries.

Preparation and Electrical Properties of Nanocomposite Based on Epoxy Resin and Core-Shell Polyaniline/Multi-Walled Carbon Nanotubes

Nanocomposites of epoxy resin containing various concentrations of carboxylated multiwalled carbon nanotubes (C-MWCNTs) and surface modified C-MWCNTs various concentration of both C-MWCNTs and core-shell nanoparticles were prepared. The physical, mechanical and electrical properties of prepared epoxy nanocomposites were investigated using experimental evaluations such as dynamic mechanical thermal analysis (DMTA), differential scanning calorimeter (DSC), and tensile strength measurements. The results of DSC tests revealed that the introduction of nanoparticles into the epoxy resin did not have much effect on the curing system, and by adding these nanoparticles to the epoxy resin, there is no need to change the curing system. However, the released energy during of epoxy curing show a 24% increase with the introduction of nanofiller into the epoxy matrix. The results of electrical conductivity measurements indicated a higher elastic dielectric constant for nanocomposites up to 200% incomparison with neat epoxy resin. The use of these epoxy nanocomposites in modern electrical and electro-optical industries is of great practical importance.

Study on enhancing mechanical and thermal properties of carbon fiber reinforced epoxy composite through zinc oxide nanofiller

This study investigates the enhancement of mechanical and thermal properties of carbon fiber reinforced epoxy composites by incorporating zinc oxide (ZnO) nanofillers. The composites were developed by adding 3–15 g of ZnO nanoparticles into the epoxy matrix and were evaluated through experimental testing. The results showed significant improvements in mechanical performance, with the maximum tensile strength of 112.49 MPa and flexural strength of 114.82 MPa at the 15 g ZnO concentration. SEM analysis revealed a reduction in void content and improved fiber-matrix adhesion, enhancing load transfer. Thermal conductivity is 13.47 W/mK, while the coefficient of linear thermal expansion is 9.29 × 10−5/°C, indicating superior thermal stability. TGA analysis demonstrated a shift in decomposition temperature from 310 to 375 °C, confirming enhanced thermal stability. These results highlight the positive influence of ZnO nanofillers on both the mechanical and thermal properties of carbon fiber reinforced epoxy composites, making them more suitable for advanced structural applications.

A novel simulation of space charge decay dynamics after removing the voltage in epoxy resin composites

Abstract Epoxy resin serves as a critical insulating component in ultra-high voltage dry direct current bushings. However, the accumulation of space charges within the epoxy resin, a byproduct of charge mobility, poses a significant risk to the reliability and operational safety of bushings. Conventional space charge attenuation models, especially after voltage removal, have limited use in simulations aimed at understanding this phenomenon. This study introduces an improved model integrating the bipolar charge transport mechanism with space charge decay based on the hopping conduction mechanism and Schottky’s theorem, establishes a theoretical framework for predicting the space charge behavior following voltage removal, and conducts a simulation to investigate the decay process within the internal structure of epoxy resin and measure the residual charges after voltage removal using the pulsed electro-acoustic method. The experimental data validate the accuracy of the proposed model and theoretical assumptions. The findings show that the remaining negative charges after voltage removal are not enhanced by the field enhancement; the anodic positive and cathodic positive charges are distributed in two-segment discontinuous traps, whereas the negative charges are distributed in one-segment traps. The model identifies two distinct trapping sites for anodic and cathodic positive charges, and one trapping site for negative charges. After voltage removal, when the field strength exceeded 40 kV mm−1, positive charges exist near the upper and lower electrodes, and negative charges exist near the center of the specimen. The consistency between the simulated predictions and experimental data proves the effectiveness of the proposed model in accurately simulating the space charge decay in epoxy materials after voltage removal.

Photothermally‐Induced Reversible Rigidity of Nacre‐Mimetic Composites Toward Semi‐Active Personal Safeguard

AbstractThe capacity to withstand challenges posed by complex environments is crucial for developing advanced high‐performance protective materials with mechanically adjustable nature. By constructing long‐range hierarchical network of shear‐stiffening gel‐carbon nanotube‐cellulose nanofiber (SCC) embedded within epoxy resin (ER), this work engineers a nacre‐inspired variable‐stiffness SCC‐ER composite (SCCE). Lightweight SCC scaffold attenuates falling impact force from 2.23 to 0.46 kN, and reaches 60 °C within 20 s under 1 sun exposure. Additionally, owing to the rigid ER matrix, SCCE exhibits 4.03 GPa elastic modulus, outperforming numerous conventional engineering materials in puncture resistance. Specific energy absorption of nacre‐mimetic SCCE presents 1.91 MJ m−3 while that of random structural SCCE is only 0.50 MJ m−3. More importantly, SCCE features representative photothermal‐induced reversible rigidity whose storage modulus varies from 9.85 MPa at 30 °C to 11.61 kPa at 116 °C under light stimulation. It also presents shape‐programmability, capable of adhering complex structural surfaces for protection. Eventually, SCCE‐based semi‐active adjustable protectors are constructed that leverage contactless photothermal effect to modulate rigidity. 5 mm‐thick smart SCCE‐protectors resist 163.93 m s−1 ballistic impact while 15‐mm commercial kneepads are penetrated at lower speed of 136.98 m s−1. This bio‐inspired semi‐active strategy proposes a promising avenue for enhancing personal protective equipment.

Concurrent experimental testing and computational micromechanical modeling of a UD NCF GFRP composite ply

The current research work presents a detailed and thoroughly validated computational micromechanical modeling methodology to study the damage initiation and propagation in a uni-directional (UD) glass fiber-reinforced non-crimp fabric (NCF) composite ply. Under the applied transverse tension and compression loads, the effect of various microscale material and geometrical parameters on the ply level stress–strain behavior is studied. To this end, along with the distinctly modeled individual microscale constituents of the UD NCF composite ply (axial fibers, backing fibers, and matrix), the generated RVE (Representative Volume Element) model consists of manufacturing-induced defects and variabilities such as voids as well as the backing fiber’s out-of-plane waviness. The fiber/matrix interface failure behavior in the generated RVE model is simulated using cohesive zone formulations that follow bi-linear traction-separation law. Whereas the hydrostatic pressure-dependent non-linear stress–strain response followed by the fracture of the epoxy matrix is captured using the linear Drucker-Prager plasticity model coupled with the stress triaxiality-based failure criterion. The backing fibers stress–strain and failure behavior is modeled using the linear elastic and isotropic material model in conjunction with the maximum stress criterion.The proposed numerical methodology is thoroughly validated both qualitatively and quantitatively by conducting detailed experiments on a neat epoxy as well as at the composite laminate level. Upon comparing the experimental and computational results, the observed knee or slope change in the bi-linear stress–strain response of the UD NCF composite ply under transverse tension is attributed to the loss of the load-carrying ability of the axial fiber bundle due to fiber/matrix interface debonding followed by the ply splitting. Under the application of transverse compression load, the composite ply failure behavior is governed by the formation of a dominant matrix plastic shear band in the axial fiber bundles, which is in turn triggered by the fiber/matrix interface failure. Under the applied loads in the matrix-dominated direction, the presented research work provides a detailed insight into the microscale damage initiation and propagation in a UD NCF composite ply and its consequent influence on the macroscale stress–strain response.

Investigating the role of fibre-matrix interfacial degradation on the ageing process of carbon fibre-reinforced polymer under hydrothermal conditions

The aqueous environment can deteriorate the fibre-matrix interface of carbon fibre-reinforced polymer (CFRP), significantly impairing the non-fibre-dominated mechanical properties. Thus, this study aimed to quantitatively analyse the impact of interfacial degradation on the hydrothermal ageing mechanism and process of the CFRP. Firstly, entire water absorption process of the CFRP under hydrothermal conditions was divided into three stages according to experimental measurement of its water content. Based on this division of stages, a novel water diffusion model was established for the hydrothermally aged CFRP. To measure the mechanical degradation, tensile tests were conducted on unaged, aged, and redried neat epoxy and transversely positioned unidirectional (UD) CFRP specimens. It was found that the transverse tensile strength degradation of UD CFRP was irreversible due to the permanent interfacial debonding between the fibres and matrix, in contrast to the reversible ageing of the epoxy matrix. To further quantify the fibre-matrix interfacial ageing, physically-based models were established for the degraded interfacial strength of CFRP subjected to hydrothermal conditions. After the characterization of the modelling coefficients, the physically-based models can be employed to predict interfacial strength inside the aged CFRP for various ageing durations. The prediction error was only 4.57 % for the transverse tensile strength of degraded UD CFRP with various ageing durations from the representative volume element (RVE) simulation with its interfacial strength provided by the physically-based models, validating the effectiveness of the proposed physically-based models for degraded fibre-matrix interface under various ageing conditions.

Optimizing dielectric constants of epoxy composites infused with Palmyra palm and nano fillers using response surface methodology

The study focuses on Palm fruit Fibers (PF) extracted from the palmyra palm tree (Borassus flabellifer) treated with 5 % alkali solution (NaOH). This treatment eliminates impurities from the fiber surface and enhances bonding with the epoxy matrix. Epoxy composites, reinforced with PF/nanofillers (h-BN, Al2O3 and MWCNT), are developed by using the box Behnken method (BBD) and dielectric constant is investigated under high-frequency and electrical field conditions. Dielectric constants (K) of the nanocomposites are determined using various capacitor terminal setups. The electrical properties of the Epoxy/PF nanocomposite, based on fiber content (Wt. %), fiber mesh size (μm) and nanofillers are evaluated using response surface methodology (RSM). Models, predicting nanocomposite dielectric constants, are established, fitting experimental values closely with R2 nearing 1 and residuals adhering to a normal probability plot. The optimized dielectric constant of 1.05 is achieved at 3 wt% palm fiber content, 150 μm fiber mesh size and 1 wt% nano h-BN.

Characterization of the natural fibers extracted from the aninga's stem and development of a unidirectional polymeric sheet.

A unidirectional sheet was made with oriented fibers in an epoxy matrix. Natural fibers were extracted from the stem of Montrichardia linifera (Arruda) Schott., traditionally known as aninga, characterized and used to produce a unidirectional polymeric sheet. FTIR, XRD, SEM, TG, and DTG analyses were performed to characterize these cellulose fibers. Peaks observed at 1024cm- 1, 1600cm- 1, and 3328cm- 1 revealed the stretching vibration of the O-H bond, the stretching of the carbonyl in hemicellulose, and the vibration of aromatic rings, respectively. XRD analysis demonstrated a crystallinity index of 62.21%. Morphological analysis revealed the microstructural quality of the fiber surface, with grooves for mechanical anchoring, as well as its interior, which is composed of microfibrils. EDS analysis confirmed the presence of the main elements composing natural fibers, with carbon being the major component (70%). The thermal stability of aninga fibers was up to 450 ºC for the degradation of 50% of their initial mass. The mechanical properties of untreated aninga fibers showed a tensile strength of 332MPa and an elastic modulus of 13.000MPa. The unidirectional sheet had a tensile strength of 4.5MPa and an elasticity modulus of 332.9MPa. These outcomes ensured that aninga fiber is considered high-performance (> 200MPa) and can be used for internal automobile components.

Extreme impact enhancement of epoxy using a sulfosuccinate-based anionic surfactant as a new modifier

In this study, disodium lauryl ether sulfosuccinate (DSL or sulfosuccinate), a commercially available anionic surfactant, was employed for the first time as an impact modifier for epoxy resin. Introducing only 5 phr of DLS into the epoxy matrix resulted in a remarkable 189% enhancement in impact strength without a significant detrimental effect on its tensile strength. According to FTIR and SEM results, the strong interaction between the modifier DLS and the epoxy matrix, along with the formation of a nano-blend morphology with a wide interfacial area, can be proposed as two key factors contributing to the remarkable enhancement in impact strength of epoxy/DLS hybrid. The thermal stability of the epoxy was not significantly affected by the incorporation of DLS up to 8 phr. The epoxy/DLS hybrid exhibited lower chemical stability against organic solvents, while the hybrid resistance to acids and bases remained largely unchanged. Based on the obtained results, DLS can be considered as a promising impact modifier for epoxy systems.

Effect of carbon fibers modification on joint adhesion steel-epoxy resin-aluminum

The combination of high-performance steel with aluminum or aluminum alloys shows a wide range of application in high technologies field like aerospace, smart materials, etc. The problem in using of adhesive bonding technology for these substrates is the weak mechanical occlusion between steel/aluminum and common coatings. In this study, different methods of treatment of carbon fiber were employed to enhance the adhesion strength in steel-epoxy resin filled with carbon fiber-aluminum triplex. The treatment of carbon fibers with 3-glicidyloxypropyl-trimetoxysilane after their oxidation in 65 wt.% nitric acid leads to the additives which improve the adhesion strength of epoxy resins at 15 wt.% contain on 67.5% in comparison with neat epoxy up to 20 MPa. This result can be explained by the change of failure mechanism from “cohesive’ to “adhesive” that leads to an increase of adhesion strength to steel and aluminum. The SEM study shown that 60–80 nm thick two-layer interphase formed between carbon fiber and epoxy matrix. The mechanical strength of this interphase governs the mechanical and adhesion performance of steel-epoxy resin-aluminum triplex. Taking into account the mechanical properties and adhesive strength of these composites, it emerges as a potential candidate for advanced materials.

An efficient moving-mesh strategy for predicting crack propagation in unidirectional composites: Application to materials reinforced with aligned CNTs

This paper presents an efficient numerical approach for reproducing the process of crack propagation inside unidirectional composites subjected to general loading conditions, with special reference to epoxy materials enhanced with embedded aligned CNTs. This approach involves a traditional FE framework improved by the Moving Mesh (MM) technique based on the Arbitrary Lagrangian-Eulerian (ALE) formulation and the Interaction Integral Method (M−integral). The MM serves as a powerful numerical tool to simulate the discrete crack advance with minimal remeshing, thus reducing the computational complexities. Instead, the M−Integral method, formulated for generally anisotropic materials, has been employed to extract the mixed-mode Stress Intensity Factors (SIFs), which are necessary to define the crack onset condition and propagation direction on the basis of the modified Maximum Hoop Stress Criterion. The proposed strategy includes the extended rule of mixtures to evaluate the homogenized elastic properties of nano-reinforced composites. The validity of the proposed methodology has been assessed through comparisons with experimental data and numerical results available in the literature.

Development and characterization of sustainable epoxy resin composites reinforced with palm kernel shell particulate and sisal fiber

This study explores the development and characterization of epoxy resin composites reinforced with palm kernel shell (PKS) particulate and sisal fibers, aiming to create sustainable and high-performance materials. Elemental composition analysis using energy dispersive X-ray revealed significant increases in carbon and oxygen content with higher PKS particulate content, indicating successful reinforcement integration. The mechanical properties were evaluated through Brinell hardness, impact energy, impact strength, tensile stress, and wear resistance tests. The Brinell hardness increased from 31.8 kg/mm2 in the control sample to a peak of 60.6 kg/mm2 in sample SP4, demonstrating enhanced hardness with PKS particulate addition. Impact tests identified an optimal reinforcement level in sample SP3, which achieved the highest impact energy (83 J) and impact strength (47.43 kJ/m2). Tensile stress analysis showed a maximum tensile stress of 28.7991 MPa for SP3, while excessive PKS content in SP4 reduced this to 20.4612 MPa. Wear tests indicated a trade-off between mechanical reinforcement and wear resistance, with the control sample exhibiting the lowest wear rates and SP4 the highest having a 91.9% increase. Based on the obtained results, SP3 with 0.8 g PKS particulate, 0.2 g sisal fiber in epoxy resin matrix seems the optimized composite with enhance mechanical properties without compromising wear resistance.

Amphiphilic block‐copolymer exfoliated transition metal dichalcogenides as novel epoxy toughening agents

AbstractExcited by the effect of amphiphilic block copolymer Polyethylene glycol‐b‐Polypropylene Glycol‐b‐Polyethylene Glycol, a triblock copolymer (TBCP) in the virgin state as well as in the grafted form with graphene oxide and multiwalled carbon nanotube in epoxy toughening, the effect of the same block copolymer in the exfoliation of graphene analogous Transition Metal Dichalcogenides (TMDs) was studied. Even though epoxy resin has several advantages, its inherent brittleness and flammability limit its application in several areas. So, there is a need for the efficient toughening of epoxy resin to make it appropriate for high‐end applications. In the present work, epoxy resin was toughened with exfoliated TMDs, especially Molybdenum sulfide and Tungsten disulfide (MoS2 and WS2). TBCP was used in the exfoliation of TMDs where the effect of these exfoliated TMDs in enhancing the properties of epoxy was evaluated. TBCP exfoliated MoS2 and WS2 exhibit fracture toughness of 483% and 636%, respectively in epoxy composites without compromising the tensile properties, which enhances the efficacy of epoxy resins towards high‐end applications. The improvement in toughness is evident from the fractography of the crack surfaces. The role of TBCP exfoliated TMDs in tuning the mechanical, thermal, and thermomechanical properties is portrayed in the manuscript, thereby unveiling the potential of yet another unique class of materials in epoxy toughening.Highlights The efficiency of amphiphilic block copolymer in exfoliating TMDs is analyzed. The effect of TBCP‐exfoliated TMDs as a toughener for the epoxy matrix is portrayed. 483% and 636% improvement in the toughness compared to neat epoxy was obtained for TBCP exfoliated MoS2 and WS2 reinforced epoxy respectively. Improved tensile properties after incorporation of TBCP exfoliated TMDs in epoxy matrix. The plasticizing effect of TBCP compromises the thermal properties.

Long-term corrosion protection of reinforcing bars via a self-responsive coating incorporating ZrP functional fillers

The conventional coating of reinforcing bars exhibits inadequate anti-corrosion efficacy stemming from a non-specific, blind protection mechanism, poses a threat to the durability of concrete. We devised a novel self-responsive functional filler, L-arginine (LA) intercalated zirconium phosphate (LCZrP), synthesized via an intercalation reaction. This innovative filler was seamlessly integrated into an epoxy (EP) resin matrix, yielding a smart anticorrosive coating that harmoniously combines active and passive corrosion protection strategies. The integration of LCZrP within the coating matrix serves a trifecta of purposes: it extends the corrosion propagation path, effectively disperses nanofiller agglomeration, and enhances interfacial adhesion with the epoxy coating. Critically, the controlled release of corrosion inhibitors from the interlayer further fortifies the coating's resistance to corrosion, imparting a multi-layered protective shield. After enduring a 60-day immersion in a simulated concrete pore solution, the LCZrP/EP coating demonstrated exceptional durability, maintaining a low-frequency impedance modulus value consistently within the range of 4.27×1010 to 5.12×1010 Ω·cm2, marking a remarkable 34-fold enhancement over the performance of the epoxy coating alone. This breakthrough underscores the LCZrP/EP coating's potential as a groundbreaking solution for reinforcing bar protection in concrete, harnessing the complementary strengths of epoxy resin's physical barrier, the impermeability of two-dimensional lamellar structures, and the proactive release of corrosion inhibitors to forge a robust, multi-faceted passivation layer.

A cotton waste reinforced composite for automotive applications: development and thermal characterization

Fibre-reinforced composites are largely used in automobiles and building materials in various forms. Thermal insulation and acoustic characteristics are being mainly considered in building construction and automotive applications to meet overall comfort conditions as well as fulfil energy efficiency requirements. It is critical to look for new and sustainable approaches to increasing the thermal characteristics of the composites. Integration of various wastes is one of the most sustainable and efficient methods for increasing the thermal characteristics of composites. The present work is aimed to investigate the thermal insulation performance of cotton waste-reinforced composites using both epoxy and modified epoxy using the C-THERM thermal conductivity analyzer according to ASTM C518 standards. A computational model of randomly dispersed epoxy matrix interphase with cotton fibers is developed and validated with experimental results. It was observed that the thermal conductivity is higher when the combination of 40% flake cotton waste and 60% matrix material is used, both for epoxy and modified epoxy. The thermal conductivity for epoxy composites is 0.5715 W/mK, while for modified epoxy composites it is 0.4935 W/mK. The results indicate that modified epoxy composites exhibit better thermal insulation properties, as they have lower thermal conductivity values compared to epoxy composites. The modified epoxy composite is considered the best for thermal insulation, can be utilised in various automotive applications, such as partitioning panels, automotive panels, brake pads, and similar applications.

Agro‐waste areca nut husk and bagasse fiber reinforced epoxy‐based hybrid composite for thermal insulated false ceiling application

AbstractIn recent years, there has been a significant push toward using environment‐friendly composite materials derived from renewable resources. Areca nut husk and bagasse fibers are excellent examples of agricultural by‐products that possess valuable properties for various applications. In this work, three samples containing 23.06%, 28.54%, and 33.33% of areca nut husk and bagasse fibers‐reinforced epoxy matrix (ABFR) hybrid composites were prepared to assess their suitability for use as thermally insulated false ceilings in affordable housing, civil structures, and the automotive industry. The novel hybrid composites were characterized by tensile strength, flexural strength, morphology, thermal conductivity, thermogravimetric analysis (TGA), and percentage of water absorption. The composite containing 23.06% fiber exhibited the lowest thermal conductivity at 0.1631 W/m K and demonstrated excellent thermal insulating properties at 0.03629%. It achieved a maximum tensile strength of 30.05 MPa and a flexural strength of 19.72 MPa. The thermogravimetric analysis indicated that the composites undergo multiple degradation steps; however, they remain stable within the temperature range of 280–328°C. The scanning electron microscope (SEM) observations revealed effective interfacial bonding between the fibers and the epoxy matrix. These characteristics suggest that this hybrid composite could be a suitable option for thermally insulated false ceilings when compared to existing synthetic fiber alternatives.Highlights The study aims to create eco‐friendly composites from areca nut husk and bagasse fiber. The hybrid composite containing 23.06% fiber showed the lowest thermal conductivity and best insulation, ideal for ceilings. More fiber in composites increased water absorption, balancing insulation with resistance. SEM micrographs clarify the proper bonding between resin and reinforcing material. Mechanical tests demonstrate superior strength and durability.

Enhanced Interfaces for High-Temperature Purposes—Practical Methodology and Characterization

The current study is focused on devising treated diatomite interfaces with the robustness and boiling water resistance necessary for high-temperature purposes. This work describes the synthesis methodology of the diatomite-based coatings, which followed the production of a composite formulation composed by treated diatomite powder dispersed in an epoxy resin matrix. After its preparation, the suspension was applied via the dip-coating technique over AISI-304 stainless-steel foils, which, after being air dried, underwent a post-curing treatment. Also, the interfaces were characterized by diverse techniques such as scanning electron microscopy and optical tensiometry. Apart from this, their thermophysical properties like thermal conductivity were also determined. Further, the physical and chemical durability of the interfaces was also evaluated via the elaboration of robustness tests including abrasion resistance, adhesion strength, solid impact resistance, and solvent resistance. The results showed satisfactory resistant interfaces, and with a wettability characterized by contact angles superior to 150°. Also, the interfaces confirmed improved durability when immersed in boiling water at 1 atm, since their wetting characteristics and durability remained nearly unaltered after 762 h of testing. Additionally, the synthesized interfaces possessed self-cleaning ability and chemical and thermal shock aging resistance. Generally, the fundamental outcomes of this work point out the suitability of the produced diatomite-based interfaces to be explored in high-temperature applications like flow boiling, pool boiling, and condensation. In terms of practicality, the method of preparation of the interfaces was a relatively easy and rapid approach to obtaining enhanced wettability and resilient interfaces, and with the required adaptations like the ratios between the raw materials, its suitability for large-scale applications makes this an appealing option.