Properties Of Epoxy Composites Research Articles

Influence of curing agent modified BN with different molecular structures on the heat conduction and electrical insulation property of epoxy composites

Influence of curing agent modified <scp>BN</scp> with different molecular structures on the heat conduction and electrical insulation property of epoxy composites

The effects of the contents of modified‐diatomite on the properties of modified‐diatomite/epoxy resin composites

AbstractExternal plasticization is one of the effective ways to toughen epoxy resins. In this study, an inorganic filler (EMD) was prepared by chemical modification of diatomite and was used to fill epoxy resin matrix. The effects of different amounts (5%, 10%, 15%, and 20%) of raw diatomite (RD) and modified‐diatomite (EMD) on the mechanical and thermal properties of epoxy resin composites were studied. The mechanical results showed that the impact strength, tensile strength, and bending strength of EMD/EP were higher than those of RD/EP. The impact strength of EMD‐15/EP reached 5.39 KJ/m2, which was 36.8% higher than that of RD‐15/EP. Thermogravimetric analysis showed that the thermal stability of EMD/EP was better than that of RD/EP. The results of DMA show that the glass transition temperature of EMD/EP was lower than that of RD/EP. Non‐isothermal differential scanning calorimetry study showed that the apparent activation energy of EMD‐15/EP was much lower than that of RD‐15/EP, which proved that EMD could promote the curing of epoxy resin. The Malek method was used to determine that both the RD‐15/EP and EMD‐15/EP curing systems were autocatalytic (Šesták–Berggren) models.

Synchronously enhancing thermal conductivity and dielectric properties in epoxy composites via incorporation of functionalized boron nitride.

Polymer-like dielectrics with superb thermal conductivity as well as high dielectric properties hold great promise for the modern electronic field. Nevertheless, integrating these properties into a single material simultaneously remains problematic due to their mutually limited physical connotations. In this study, we developed high-quality thermally conductive epoxy composites with excellent dielectric properties. This was achieved by incorporating surface-functionalized microscale hexagonal boron nitride (BN) along with N-[3-(Trimethoxysilyl)propyl]ethylene diamine (DN) and N-[3-(Trimethoxysilyl)propyl]aniline (PN). In the resulting epoxy composite, microscale BN serves as the primary building block for establishing the thermally conductive network, while silica particles act as bridges to regulate heat transfer and reduce interfacial phonon-scattering. The prepared composites were thoroughly examined across various filler contents (ranging from 10 to 80 wt%). Among them, the DNBN/epoxy composite exhibited higher thermal conductivity (in-plane: 47.03 W m-1 K-1) at 60 wt% filler content compared to BN/epoxy (39.40 W m-1 K-1) and PNBN/epoxy (33 W m-1 K-1) composites. These results highlight the usefulness of surface modification of BN in improving compatibility between fillers and epoxy, ultimately reducing composite viscosity. Furthermore, the DNBN/epoxy composite at 60 wt% demonstrated superb dielectric constant (∼6.15) without compromising on dissipation loss (∼0.06). The strategy adopted in this study offers significant insights into designing dielectric thermally conductive composites with superior performance outcomes.

Heterostructured three-dimension MXene/short carbon fiber to enhance thermal, mechanical and tribological properties of epoxy composites

Heterostructured three-dimension MXene/short carbon fiber to enhance thermal, mechanical and tribological properties of epoxy composites

Tribological synergy of copper‐based metal–organic frameworks, carbon fibers and SiO2 in modifying the friction and wear properties of epoxy composites

AbstractCopper‐based metal–organic frameworks is anticipated to find applications in the field of friction materials owing to its plentiful surface‐active groups and distinctive framework structure. In this study, copper‐based metal–organic frameworks was synthesized through ultrasound‐assisted method and incorporated alone into carbon fiber reinforced epoxy composites or together with SiO2 nanoparticles towards the goal of improving the composites' friction and wear properties. It is revealed that copper‐based metal–organic frameworks alone cannot improve the friction and wear of carbon fiber reinforced epoxy composites simultaneously. The combination of copper‐based metal–organic frameworks and SiO2 nanoparticles was more effective in enhancing both the mechanical and tribological properties of studied composites. The composite material exhibits a friction coefficient of 0.104 under the specified test conditions of 10 MPa and 3.75 m/s. Additionally, the specific wear rate is impressively low, measuring only 5.64 × 10−7 mm3 N/m. Through morphological and chemical analysis on the worn surfaces and transfer films, the functioning mechanism of copper‐based metal–organic frameworks in modifying the mechanical and tribological properties was discussed. It was discovered that a tribological synergy exists between short carbon fibers, copper‐based metal–organic frameworks, and SiO2 fillers, leading to a shift in the wear mechanism of the composite materials from abrasive wear to adhesive wear. Concurrently, a shear‐prone transfer film forms on the surface of the counter steel surfaces. Findings of the present study pave a new route of designing high performance epoxy based tribo‐composites by using metal–organic frameworks.Highlights Cu‐BDC nanosheets were synthesized using ultrasound‐assisted techniques and incorporated as tribological fillers in EP composites. The combined use of Cu‐BDC, SiO2, and SCF fillers synergistically enhances the mechanical and tribological properties of EP composites. The composite material exhibits a friction coefficient of 0.104 under the specified test conditions of 10 MPa and 3.75 m/s, the specific wear rate is impressively low, measuring only 5.64 × 10−7 mm3N/m. During the sliding friction process of the composite materials, Cu‐BDC and SiO2 play a crucial role in reducing SCF pull‐out wear through their anchoring effect. The dynamic coordination bond structure of Cu‐BDC contributes to the formation of uniform and continuous transfer films on counter metal surfaces.

Effect of Clay Composition and Human Haircut Waste on Mechanical Properties Mechanical Properties of Epoxy Resin Composites

The impact of human haircut waste and the nature of clay soil on the mechanical characteristics of epoxy resin composites has been studied. This study utilizes clay sourced from Wonosari Village, Deli Serdang Regency. The clay was pulverized using a pestle and mortar until it reached a smooth consistency. It is then filtered through a 200 mesh screen and subjected to drying in an oven at a temperature of 105℃ for around 3 h until the water content is completely evaporated. Finally, the dried clay stored in a desiccator. The clay powder was subjected to ball milling for 40 h at 350 rpm. The resulting particle size, determined by particle size analysis (PSA), was found at 0.764 µm. Next, the human haircut waste obtained from the surrounding campus of Universitas Sumatera Utara was prepared by separating the hair from fine hair and washing it clean. Clay soil powder and human hair cut waste are used as fillers, and some variations of epoxy resin mixtures are used. Morphological SEM analysis shows that clay and human haircut waste can be distributed evenly on epoxy resin composites. Testing of water absorption and mechanical properties of the board based on SNI 01-449-2006 standards include the test of dry bending strength (MoR) and the mode of flexural elasticity (MoE) obtained the optimum composition (50: 50: 1: 1) g against the epoxy resin mixture, waste human haircut, and clay soil obtained the water absorption test results of 1.64% with a value of MoE 36789.03 kgf /cm2 and a value of MoR 664,41 kgf/cm2. Test results of mechanical properties and water absorption have fulfilled the SNI 01-449-2006 quality standards for composite boards.

Effect of holmium oxide nanoparticle on the mechanical properties of epoxy resin composites

In this study, holmium oxide/epoxy resin (Ho2O3/EP) nanocomposites were prepared by using different additions of Ho2O3 nanoparticles as nanofiller. The surface-modification treatment of Ho2O3 was applied with a silane coupling agent (SCA) to improve the interfacial combination between Ho2O3 and EP. The effect of SCA treatment on the chemical structure of Ho2O3 was investigated using Fourier transform infrared spectroscopy (FTIR). The effects of Ho2O3 nanoparticle and SCA treatment on the mechanical properties of the nanocomposites were studied. The fracture morphology of the EP nanocomposites was observed by scanning electron microscopy (SEM) to explore the failure mechanism of the EP nanocomposites with Ho2O3 nanoparticle. The experimental results show the tensile and flexural strengths of the nanocomposites are improved when Ho2O3 content is 1 wt. %. The tensile and flexural strengths were increased to 73.42 MPa and 130.85 MPa, respectively. But on further increase in Ho2O3 content of 1.5 wt. %, the tensile and flexural strengths were reduced. The SCA treatment could increase the interfacial bonding by containing C-H and Si-O functional groups, promoting the tensile properties, flexural properties, impact toughness, and fracture properties of the nanocomposites.

Thermo‐mechanical properties of epoxy composites filled with inorganic particulate fillers for robust solder mask application

AbstractFiller components play a crucial role as thermo‐mechanical reinforcement to the epoxy‐based solder mask, ensuring effective insulation and passivation. This study investigates the impact of different inorganic filler types (talc, silica (SiO2), boron nitride (BN) and barium sulfate (BaSO4)) and loadings (5 and 15 wt%) on the tensile and thermal properties of the epoxy composites. The composites were blended, cast and thermally cured. Of these composites, only 15 wt% SiO2/epoxy composite exhibits notable increments in both tensile strength and modulus, surpassing unfilled epoxy by 11.65% and 31.9%, respectively. It also displays the highest elongation at break, supported by small particle size, high specific surface area and minimal void volume fraction. For thermal tests, the addition of all fillers increases the storage modulus in both glassy and rubbery regions, especially 15 wt% talc/epoxy composite with 30.09% increment at 25 °C. Additionally, all fillers raise the glass transition temperature (Tg), notably improving it by 9 °C in the 15 wt% BN/epoxy composite. Moreover, their inclusion generally enhances the onset decomposition temperature (Tonset) and reduces weight loss during decomposition. © 2024 Society of Chemical Industry.

Evaluating the Effects of Metallic Waste on the Structural and Gamma-Ray Shielding Properties of Epoxy Composites.

The objective of the research is to develop novel materials that are both inexpensive and have a low density, while also being able to endure the transportation of γ-photons with low-to-medium energy levels. The outcome consisted of four epoxy resins that were strengthened with different quantities of heavy metallic waste. The density of the formed composites improved from 1.134 ± 0.022 g/cm3 to 1.560 ± 0.0312 g/cm3 when the waste content was raised from 0 to 40 weight percent. The theoretical investigation was determined using Monte Carlo (MCNP) simulation software, and the results of linear attenuation coefficient were justified experimentally in a low and medium energy range of 15-662 keV. The mass attenuation coefficient results in a low gamma energy range (15-122 keV) varied in between 3.175 and 0.159 cm2/g (for E-MW0 composite) and in between 8.212 and 0.164 cm2/g (for E-MW40 composite). The decrease in mass attenuation coefficient was detected in a medium gamma photon energy range (122-662 keV) with 0.123-0.082 cm2/g (for E-MW0 composite) and 0.121-0.080 cm2/g (for E-MW40 composite). The density of the enhanced composites influenced these parameters. As the metallic waste composition increased, the fabricated composites' half-value thickness decreased. At 15 keV, the half-value thickness decreased from 0.19 to 0.05 cm. At 59 keV, it fell from 2.70 to 1.41 cm. At 122 keV, it fell from 3.90 to 2.72 cm. At 662 keV, it fell from 7.45 to 5.56 cm. This decrease occurred as the heavy metal waste concentration increased from 0 to 40 wt.%. The study indicates that as metallic waste concentrations rise, there is a rise in the effective atomic number and a decline in the buildup factors.

Mechanical and Vibration Properties of Epoxy Composites Reinforced with Sisal, Areca, and Hemp Fibers, Enhanced by Sugarcane Bagasse and Coconut Husk Fillers

Mechanical and Vibration Properties of Epoxy Composites Reinforced with Sisal, Areca, and Hemp Fibers, Enhanced by Sugarcane Bagasse and Coconut Husk Fillers

Optimized Functionalization of Graphene Oxide for Enhanced Mechanical Properties in Epoxy Resin Composites

Optimized Functionalization of Graphene Oxide for Enhanced Mechanical Properties in Epoxy Resin Composites

A comprehensive study on the effect of small rates of walnut shell and talc fillers on the thermal,mechanical, and morphological properties of epoxy hybrid composites

AbstractEpoxy-based composites, valued for their cost-effectiveness and remarkable mechanical properties, attract considerable attention from researchers in academia and industry. This study explores the impact of low concentrations (1% to 3%) of walnut shell (WS) and talc additives on the density, water absorption, and mechanical (tensile, three-point bending, impact, hardness) as well as thermal (TGA, DSC) properties of epoxy composites. While prior research has extensively covered epoxy composites with high concentrations of walnut shell and talc, their utilization in lower concentrations remains underexplored. Findings highlight the substantial influence of incorporating low percentages of walnut shell and talc on the Tg temperatures of epoxy composites, with talc reducing Tg temperature and WS elevating it. TGA tests reveal that both WS and talc contribute to increased Tmax temperature and residue content compared to pure epoxy. Mechanical properties exhibit variations based on filler type and amount, with walnut shell enhancing the elastic modulus and talc decreasing it compared to pure epoxy. Impact resistance sees significant reductions related to particle size. Talc boosts density, while WS has a more pronounced effect on hardness. Water absorption tests demonstrate higher water absorption in WS-containing epoxy composites. Glossiness and surface roughness undergo changes, with talc increasing roughness and decreasing glossiness. In conclusion, even minor filler percentages noticeably impact epoxy composite properties compared to pure epoxy, providing avenues for customized modifications, particularly with challenging or costly fillers, offering viable alternatives for researchers in diverse fields.

Synergistically enhanced electromagnetic interference shielding and mechanical properties of epoxy resin composites with a preconstructed hierarchical structure

AbstractElectromagnetic interference (EMI) shielding materials have attracted extensive attention as highly integrated electronic devices generate large amounts of electromagnetic pollution. Here, PNF/NGx‐EP composites with excellent EMI shielding properties and superior flexural strength were reported, where nickel‐plated carbon fiber (NF) felts and NH2‐Graphene (NG) were adopted to pre‐construct a hierarchical structure within epoxy resin (EP). The macroscopic NF network constructed a continuous conductive pathway and the NG grafted on the surface of NF formed a second microscopic conductive network. Consequently, the PNF/NG0.5 felts exhibited a quite high electrical conductivity of 138.4 S/cm, and the PNF/NG0.5‐EP composites presented excellent EMI shielding effectiveness (EMI SE) (57.4 dB at 11.9 GHz). Intriguingly, the flexural strength of the NF/EP composites was enhanced after the incorporation of NG, which was attributed to the mechanical locking effect and covalent bonding. In summary, this approach reconciles the contradiction between EMI shielding properties and mechanical properties of EP composites, and allows them to be promisingly employed for EMI shielding and protection in aerospace, weaponry, and communications.Highlights A hierarchical structure of PNF/NGx felts was preconstructed within EP via Michael addition/Schiff base reaction. The PNF/NGx‐EP composites exhibited remarkable EMI shielding properties (57.4 dB) and superior flexural strength (137.0 MPa), which are expected to realize practical applications in EMI shielding.

Effect of alumina fillers on physical and mechanical properties of luffa/groundnut shell natural fiber reinforced polymer composites

AbstractThis study aims to investigate the physical and mechanical properties of epoxy composites reinforced with hybrid luffa waste and groundnut shell waste natural fibers and to evaluate the effect of different filler loadings of alumina on the mechanical behavior of the hybrid composites. The luffa fibers were made to undergo mercerization in 10% NaOH solution. All the treated fibers and the alumina fillers were characterized using X‐ray diffraction analysis (XRD). The study used three different filler loadings of alumina (Al2O3) (5%, 10%, and 15% by volume) and three different fractions of treated luffa‐waste groundnut shell hybrid fibers (10%, 30%, and 50% by volume). The composites were fabricated using the hand layup technique, and the prepared test specimens were subjected to mechanical and physical properties testing as per ASTM standards. The experimental findings indicated that the inclusion of Al2O3 filler improved the physical and mechanical characteristics of the natural fiber‐reinforced hybrid composites. The results showed that the composites with 30 vol. % fibers (1:1 luffa fiber: groundnut shell fiber) and 10 vol. % Al2O3 content showed enhanced tensile, flexural, shear, and impact strength and hardness. Besides, a good synergy between the alumina fillers, natural fibers, and the polymer matrix was observed in the surface morphology of the composite specimen. The developed composites can be used in low and medium‐load‐bearing structural and non‐structural applications.Highlights Development of hybrid polymer composites with luffa and novel groundnut shell fibers Hybridization of alumina ceramic particles with natural fiber hybrid composites Assessment of physical and mechanical properties of the polymer composites

Role of carbon quantum dots from lychee fruit husk waste and discarded caster bean stem fiber on load bearing, fatigue, and water uptake properties of epoxy composite

Role of carbon quantum dots from lychee fruit husk waste and discarded caster bean stem fiber on load bearing, fatigue, and water uptake properties of epoxy composite

Investigation of the mechanical and physical properties of mesoporous silicon dioxide fillet epoxy composites

In this study, the effect of mesoporous silicon dioxide (M-SiO2) additives with different surface areas and pore diameters on the morphological and mechanical properties of epoxy composites was investigated. For this purpose, M-SiO2 particles with different pore diameters and surface areas were synthesized from polyethylene glycol (PEG) with three different molecular weights (PEG2000 (PEG2), PEG6000 (PEG6), and PEG35000 (PEG35) kDa) using the one-step sol-gel technique. The mixing of epoxy resin, hardener and M-SiO2 fillers, was carried out in a mould followed by using ultrasonic bath and mechanical stirrer.The mechanical properties of the composites, including hardness, tensile strength, elongation at break, and modulus of elasticity, were studied. FT-IR spectra and XRD patterns show that M-SiO2 is distributed homogeneously in the epoxy. The epoxy/PEG35M-SiO2 composites' tensile strength (8.7%) and modulus of elasticity (23.3%) increased with the addition of PEG35M-SiO2, however their elongation at break (5.1%) decreased.

A comprehensive experimental study on the effects of hexagonal boron nitride particle size and loading ratio on thermal and mechanical performance in epoxy composites

Harnessing the potential of hexagonal boron nitride (h-BN) in epoxy composites for tailoring thermal conductivity is a promising avenue in materials science. However, achieving balanced enhancements in both in-plane and through-plane directions remains a challenge that requires innovative solutions. The primary objective of this research is to evaluate how thermal and mechanical characteristics of an epoxy matrix are affected by the size and amount of h-BN particles. To achieve this goal, h-BN particles with varying sizes (micro and nano) are incorporated into the epoxy matrix at different weight ratios spanning from 0.5 wt % to 20 wt % using a pre-dispersion technique. The epoxy composites reinforced with h-BN through a molding process exhibits enhanced mechanical and thermal performance in contrast to the pristine epoxy material. During the flexural test, acoustic emission data is collected to identify the initiation and progression of damage within the specimens under testing conditions. The most notable enhancement in thermal conductivity is observed when incorporating 20 wt% of micron-sized h-BN particles. This leads to a remarkable 107% increase in the in-plane direction and an impressive 112% increase in the through-plane direction. These results can be attributed to the formation of a three-dimensional thermally conductive network by the larger h-BN particles, which extends the path of phonon scattering. Furthermore, there are significant improvements in both flexural modulus and tensile modulus. Epoxy composites containing 10 wt% of micron-sized h-BN experiences an approximate 42% increase, while those with 20 wt% of the same particles displays a substantial 47% rise in these properties. This study effectively addresses the challenges associated with tailoring the thermal properties of epoxy composites, opening up new opportunities for applications in various industries, including electronics, aerospace and thermal management systems.

Modeling and analysis of TiO2 filler's impact on specific wear rate in flax fiber-reinforced epoxy composite under abrasive wear using Taguchi approach

PurposeThis study explores how titanium oxide (TiO2) filler influences the specific wear rate (SWR) in flax fiber-reinforced epoxy composites (FFRCs) through a Taguchi approach. It aims to boost abrasive wear resistance by incorporating TiO2 filler, promoting sustainable and eco-friendly materials.Design/methodology/approachThis study fabricates epoxy/flax composites with TiO2 particles (0–8 wt%) using hand layup. Composites were tested for wear following American Society for Testing and Materials (ASTM) G99-05. Statistical analysis used Taguchi design of experiments (DOE), with ANOVA identifying key factors affecting SWR in abrasive sliding conditions.FindingsThe study illuminates how integrating TiO2 filler particles into epoxy/flax composites enhances abrasive wear properties. Statistical analysis of SWR highlights abrasive grit size (grit) as the most influential factor, followed by normal load, wt% of TiO2 and sliding distance. Grit size has the highest effect at 43.78%, and wt% TiO2 filler contributes 15.61% to SWR according to ANOVA. Notably, the Taguchi predictive model closely aligns with experimental results, validating its reliability.Originality/valueThis paper integrates TiO2 filler and flax fibers to form a novel hybrid composite with enhanced tribological properties in epoxy composites. The use of Taguchi DOE and ANOVA offers valuable insights for optimizing control variables, particularly in natural fiber-reinforced composites (NFRCs).

Investigation of fracture behavior and mechanical properties of epoxy composites supported with MWCNTs microscopically

Adding of a multi-walled carbon nanotubes (MWCNTs) to epoxy resin has shown promising results in improving fracture toughness in bulk epoxy and carbon fiber-reinforced epoxy composites (CFRP). using a hand layup proceeding followed by the so called vacuum bagging process method, carbon fiber-reinforced polymer multi-wall carbon nanotubes (MWCNTs) was added to an epoxy resin with a weight percentage mixing of 1% wt., 1.25% wt., and 1.5 % wt. MWCNTs. Furthermore, the specimen underwent analysis via Fourier-Transform Infrared (FTIR) spectroscopy, and X-ray Diffraction (XRD) spectroscopy, the composites were subjected to a microscopic examination using a Scanning Electron Microscope (SEM). FTIR and XRD verified the folding and unfolding of the polymer, in addition, the mechanical properties including tensile strength, bending stress, and impact behavior were investigated as well as the hardness test. The obtained results showed a significant improvement of about (40 %) in tensile strength, (53 %) in bending stress at 1 % wt. MWCNTs, and (70 %) percentage increment in the strength of Impact at 1.25 % wt. MWCNTs. And the gained hardness was about 40.5 HV which were compared with a reference substance named Carbon Fiber (CF) without any addition of nano materials. Carbon nanotubes have demonstrated their potential to enhance the mechanical properties of fiber-reinforced polymers, so this investigative study employs comprehensive characterization techniques, and demonstrates significant improvements in mechanical properties for the modified polymeric composite materials supported with nano materials.

Studying the Structure and Properties of Epoxy Composites Modified by Original and Functionalized with Hexamethylenediamine by Electrochemically Synthesized Graphene Oxide.

In this study, we used multilayer graphene oxide (GO) obtained by anodic oxidation of graphite powder in 83% sulfuric acid. The modification of GO was carried out by its interaction with hexamethylenediamine (HMDA) according to the mechanism of nucleophilic substitution between the amino group of HMDA (HMDA) and the epoxy groups of GO, accompanied by partial reduction of multilayer GO and an increase in the deformation of the carbon layers. The structure and properties of modified HMDA-GO were characterized using research methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy and Raman spectroscopy. The conducted studies show the effectiveness of using HMDA-OG for modifying epoxy composites. Functionalizing treatment of GO particles helps reduce the free surface energy at the polymer-nanofiller interface and increase adhesion, which leads to the improvement in physical and mechanical characteristics of the composite material. The results demonstrate an increase in the strength and elastic modulus in bending by 48% and 102%, respectively, an increase in the impact strength by 122%, and an increase in the strength and elastic modulus in tension by 82% and 47%, respectively, as compared to the pristine epoxy composite which did not contain GO-HMDA. It has been found that the addition of GO-HMDA into the epoxy composition initiates the polymerization process due to the participation of reactive amino groups in the polymerization reaction, and also provides an increase in the thermal stability of epoxy nanocomposites.