Properties Of Epoxy Matrix Composites Research Articles

An experimental study on the effect of graphite microparticles on the mechanical and tribological properties of epoxy matrix composites

This article comprehensively discusses the mechanical and tribological properties of epoxy matrix composites filled with 100μm graphite particulates, at loadings ranging from 0 to 1wt%. The investigation also focuses on the effects of the graphite filler on the wear surface of the specimens, utilizing an optical microscope for analysis. The results revealed a significant decrease in the tensile strength of the composite, with a reduction of more than 50% observed at 1wt% graphite loading. However, the flexural strength exhibited an initial sharp increase at 0.1wt% graphite loading, followed by a decline at higher graphite contents. Moreover, both impact and hardness values demonstrated improvement as the graphite content increased. The addition of graphite particles led to a reduction in the friction coefficient, attributed to the solid lubrication capabilities of graphite. Furthermore, the wear rate exhibited a sharp decrease with an increase in graphite content due to the formation of a lubrication layer at the contact surface, effectively reducing the break-off of the specimen.

The Effect of Short Carbon Fiber and Hydrothermal Carbon Content on Impact and Wear Properties of Epoxy Composites

This study aims to investigate the effect of different weight fractions (3%, and 5%) of short carbon fibers (SCFs) and hydrothermal carbons (HTCs) on the impact and wear properties of epoxy matrix composites. The samples were fabricated using the hand lay-up method. Izod impact tests were applied to the unnotched samples. To investigate the wear properties of pure epoxy and composites, reciprocating wear tests were conducted. Also, a Scanning Electron Microscope has been used for observation of the morphology of the broken and worn surfaces of pure Epoxy and (SCFs and HTCs) reinforced epoxy-based composites. Results showed that HTCs have remarkable effects on improving the wear resistance rate as compared to SCFs reinforced composites. However, SCFs reinforced epoxy composites have better energy-absorbing effects compared to HTCs epoxy-reinforced composites.

The Production and Characterization of Seashell Reinforced Epoxy Composite Material

In this study, it was aimed to examine the production, characterization and mechanical properties of epoxy matrix composites added with seashells collected from different coastal locations of the Mersin Region, which is a natural raw material. Natural seashells with different mass ratios were ground into different sizes and added into epoxy, the matrix material. By performing physical and chemical characterization of the produced composites, the next step is to analyze and produce the product with the best and most superior properties.

Investigation of effect of chestnut sawdust on mechanical properties of epoxy matrix composites

Investigation of effect of chestnut sawdust on mechanical properties of epoxy matrix composites

Combustion characteristics and quantitative determination of energy release of Epoxy-Al active materials projectile hypervelocity impact steel targets in vacuum environment

Epoxy resin is often used to intermediate of structural materials or adhesives as an important raw material and product of modern industry by low density, high strength and easy molding, which plays an important role in the field of composite materials. However, the current research mainly focuses on the mechanical properties of epoxy matrix composites under quasi-static and low strain rate loading, and there is little research on the properties of Epoxy-metal composites under high-speed loading. In this paper, Epoxy-Al5μm (70 wt%/wt30%) samples were prepared by adding active metal aluminum powder to epoxy resin and vacuum curing. The reaction-release energy and combustion characteristics of Epoxy-Al active materials projectile hypervelocity (2.85–3.46 km/s) impact steel targets in vacuum environment were studied by two-stage light gas gun loaded combined with a high-speed camera, an infrared thermal imager, a transient overpressure testing system and a transient optical fiber pyrometer. The results show that the Epoxy-Al material exhibits strong chemical energy release and combustion characteristics under hypervelocity impact load. The energy release can reach 21.36 kJ/g, which is much higher than the existing PTFE/Al active materials (8.23 kJ/g). The whole reaction process can be divided into three stages: accelerated reaction stage, decelerated reaction stage and after effect stage, a stable combustion phenomenon exists in the deceleration reaction period. In the accelerated reaction stage, the average reaction speed of the Epoxy-Al projectile is 1.4 km/s and the maximum temperature is 1650 K.

Thermal Mechanical Property Enhancement with Silicon Carbide Ceramic Filled Composites for Industrial Applications

Epoxy composites with glass fiber reinforcement can be found in the automotive and aerospace industries. In this study, the properties of the epoxy matrix were enhanced by processing composites filled with ceramic particles of silicon carbide (SiC). At first, SiC-filled E-glass fiber-reinforced epoxy composites/sandwich structures were processed using the hand layup technique. Next, processed composites were characterized using a tensile tester and an Izod impact tester to determine the best mixing ratio of ceramic-embedded epoxy composites. The highest mechanical properties were obtained according to ASTM D638 and D256 standards. Next, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), analysis of differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) were carried out respectively to find out the presence of functional groups, surface morphology, crystallographic structure, glass transition temperature (Tg) and thermal/material stability of processed composites. In the end, the study elaborates that the mechanical properties of epoxy matrix composites were improved by the addition of SiC ceramic fillers, and among processed composites, 10% SiCE composite carried the highest properties, including the Tg value of 62.8 °C, 69.87 MPa for tensile strength and 57.12 kJ m−1 for impact strength.

Shielding Properties of Epoxy Matrix Composites Reinforced with MgO Micro- and Nanoparticles.

The aim of the current study is to investigate the impact of introducing micro- and nanoparticle MgO as a filler into epoxy resin on the radiation shielding abilities of the prepared samples. To this end, we performed a gamma-radiation spectroscopy experiment with the help of an HPGe detector and Am-241, Cs-137, and Co-60 sources. We evaluated the particle size effect (PSE) and detected the maximum PSE value with the addition of 50 wt% MgO particles, indicating that nanoparticle MgO was more successful in shielding against incoming radiation than microparticle MgO. We compared the half-value layer (HVL) for the samples with 10 wt%, 20 wt%, and 30 wt % micro-MgO and nano-MgO and found that the HVL values were lower for the nanoparticle samples than for the microparticles samples, confirming that smaller particle sizes enhanced the shielding ability of the samples against radiation. The MFP results showed that epoxy matrices containing micro-MgO, for all investigated energies, resulted in higher MFP values that those containing nano-MgO.

Elastic and Fracture Properties of Epoxy Matrix Composites Reinforced With Multi-Walled Carbon Nanotubes

Elastic and Fracture Properties of Epoxy Matrix Composites Reinforced With Multi-Walled Carbon Nanotubes

The impact of fibre processing on the mechanical properties of epoxy matrix composites and wood-based particleboard reinforced with hemp (Cannabis sativa L.) fibre

This work investigated the impact that the processing of hemp (C. sativa L.) fibre has on the mechanical properties of unidirectional fibre-reinforced epoxy resin composites loaded in axial tension, and particleboard reinforced with aligned fibre bundles applied to one surface of the panel. For this purpose, mechanically processed (decorticated) and un-processed hemp fibre bundles, obtained from retted and un-retted hemp stems, were utilised. The results clearly show the impact of fibre reinforcement in both materials. Epoxy composites reinforced with processed hemp exhibited 3.3 times greater tensile strength when compared to the un-reinforced polymer, while for the particleboards, the bending strength obtained in those reinforced with processed hemp was 1.7 times greater than the un-reinforced particleboards. Moreover, whether the fibre bundles were processed or un-processed also affected the mechanical performance, especially in the epoxy composites. For example, the un-processed fibre-reinforced epoxy composites exhibited 49% greater work of fracture than the composites reinforced with processed hemp. In the wood-based particleboards, however, the difference was not significant. Additionally, observations of the fracture zone of the specimens showed different failure characteristics depending on whether the composites were reinforced with processed or un-processed hemp. Both epoxy composites and wood-based particleboards reinforced with un-processed hemp exhibited fibre reinforcement apparently able to retain structural integrity after the composite’s failure. On the other hand, when processed hemp was used as reinforcement, fibre bundles showed a clear cut across the specimen, with the fibre-reinforcement mainly failing at the composite's fracture zone.

Novel evaluation of flammability attenuation and thermal characteristics elevation potential of polymer composites reinforced with cucumeropsis mannii shell granules

In recent times, effort has been made by researchers all over the world to develop composite materials that will be eco-friendly and affordable. Based on this, this study focused on the development of improved thermal and fire properties of the polymer (epoxy) using Cucumeropsis mannii shell granules (CMSg). Epoxy + 20wt% CMSg composite was produced by solution casting method. The thermogravimetric (TGA) and cone calorimetry were used to determine the relevant characteristics of the composite. The temperature of thermal maximum decomposition was shifted to a higher temperature for the composite. The epoxy released 6.63% heat during burring and 6.73% mass loss over that of the developed composite. About 58.93% delayed time was obtained for the composite before burning commenced. The results show that the tested material can be used for increasing the thermal and fire properties of epoxy matrix composites for engineering application.

Experimental investigations on mechanical properties and abrasive wear response of glass, kevlar and carbon fabric reinforced composites

Comparative investigations have been done to evaluate the effect of type of fabric (glass, kevlar and carbon) reinforcement on mechanical, three body abrasive wear rate and thermo mechanical properties of epoxy matrix composites. Mechanical properties i.e. hardness, tensile strength, flexural strength, inter laminar shear strength and impact strength are determined for change in weight percentage of fabric reinforcement to notice the behavior of the material when subjected to respective loading. Experiments have been conducted to notice the effect of three body abrasive wear rate on glass, kevlar and carbon fabric. Dependent factors such as fabric reinforcement, abrasive particle size, normal load, sliding velocity and distance travelled are varied in steps to analyze the effect of each factor on type of fabric reinforcement. Results show that with increase in fabric loading the mechanical properties augment to a certain extent and further increment leads to drop in mechanical properties. Wear rate increases with the increase in normal load and other factors also have a substantial effect on abrasive wear rate. Overall behavior of carbon fabric is found to be better than that of glass and kevlar fabric reinforced composites.

On the determination of the elastic constants of carbon fibres by nanoindentation tests

Nano-indentation instrumented tests are carried out at shallow depths on PAN-based and MPP-based carbon fibres. Indentation moduli are obtained by performing the tests at ten different measured orientations with respect to the fibre axis. They are used to identify the elastic constants of the fibres, assuming a transversely isotropic behaviour, by minimising a cost function between measured and estimated values. Inconstancies between the identified in-plane shear and transverse moduli and reported literature values are pointed out, and some drawbacks of the nano-indentation method are highlighted. An improved method taking into account the buckling mechanisms of crystallites at stake during the indentation process, and visible in the hysteretic behaviour of force-penetration nanoindentation curves, is proposed. It allows to identify values of elastic constants that are in accordance with literature values. These elastic properties of carbon fibres are in turn used to estimate the elastic properties of epoxy matrix composites containing these fibres. Very good agreement is found with experimentally available values of unidirectional ply properties. An excellent correlation between experiments and Finite Element Analyses of the indentation response of carbon fibres is eventually found.

Influence of amine functionalized graphene oxide on mechanical and thermal properties of epoxy matrix composites

A new approach for synthesized amine functionalized graphene oxide (AFGO) was used by diethylenetriamine as a reducing or functionalizing agent. The purpose of this work is to determine the effect of AFGO on the mechanical and thermal properties of epoxy nanocomposites. In addition, the optimization of various weight percentages of AFGO was carried out. Physical and chemical characterizations were also reported to determine the effects of AFGO. The structure and morphology of the AFGO nanosheets were confirmed by fourier transform infrared spectroscopy, energy dispersive spectroscopy, X-ray diffraction analysis, and field emission scanning electron microscopy. Successful formation of amide bonds through graphene oxide (GO) sheet functionalization was proved by characterizations. Solution blending, as a simple method, was used for composite formation. The mechanical and thermal properties of the epoxy/AFGO composites were assessed. There was increment in tensile strength by 67%, flexural strength by 51%, and impact strength by 152% at 0.3 wt% loading of AFGO in epoxy composites. Similarly, the increment in hardness was also observed from 0.1 to 0.3 wt% of AFGO loading. The glass transition temperature of epoxy/AFGO nanocomposites effectively improved from 88.4 to 97.3 °C. The thermal stability of epoxy/AFGO nanocomposite increased from 351 to 358 °C.

A combination of graphene and graphene nanoplatelets: An effective way to improve thermal conductivity for polymers

Graphene has emerged as an efficient filler in polymer matrices due to its unique properties. What is not entirely clear, however, is how to transfer the unique attributes exhibited at the nanoscale to the macroscale. The primary focus of this study was on understanding the main causes that lead to the improvement of thermal conductivity for polymers with a hybrid reinforcement material consisting of graphene and graphene nanoplatelets. The thermal properties of epoxy matrix composites filled with the hybrid reinforcement material were studied experimentally in order to provide an effective way to improve thermal conductivity for polymers. Comparisons with other existing reinforcement materials were made in terms of thermal properties. A mathematical model was developed to evaluate the effectiveness of the hybrid reinforcement material in improving thermal conductivity. The results indicated that a twenty-fold increase in thermal conductivity can be achieved for epoxy resins when the content of the hybrid reinforcement material is 8% by weight. The main cause is that the hybrid reinforcement material can significantly reduce interfacial thermal resistance. The hybrid reinforcement material is quite effective compared to other existing reinforcement materials. The thermal performance of the resultant composite materials has no significant degradation at high temperatures.

Effect of thermal shock cycling on the quasi‐static and dynamic flexural properties of flax fabric‐epoxy matrix laminates

ABSTRACTThe aim of the present work is to investigate the influence of thermal shock cycling on the quasi‐static and dynamic flexural properties of epoxy matrix composites reinforced with natural flax fibers fabric. Polymer composite laminates reinforced with four plies of natural flax fiber fabric have been manufactured. The samples have been exposed to different number of thermal shock cycles (0, 50, 100, 200, 300, 400), at a temperature range from −40 °C to +28 °C. Dynamic mechanical analysis (DMA) tests were performed on both pristine and thermally shocked specimens in order to determine their viscoelastic response. Due to the thermal shock cycling and after 100 thermal shock cycles, a maximum decrease in storage and loss modulus on the order of 50% was observed. After 100 thermal shock cycles, no further degradation of dynamic properties was observed. On the contrary, damping factor and glass transition temperature values showed a minor variation as number of thermal shock cycles increased. In addition, the time–temperature superposition principle (TTSP) was successfully applied, confirming the fact that the flax fiber fabric‐epoxy laminate is a thermo‐rheologically simple material. Likewise, quasi‐static three‐point bending tests were executed and a maximum decrease of 20% in flexural strength was observed after 400 thermal shock cycles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48529.

Mechanical Properties of Epoxy Matrix Composites Toughened by Liquid Epoxidized Natural Rubber (LENR)

Mechanical Properties of Epoxy Matrix Composites Toughened by Liquid Epoxidized Natural Rubber (LENR)

Influence of different nanomaterials on the mechanical properties of epoxy matrix composites

Abstract Carbon nanotubes (CNTs) and other nanoparticles such as silicon carbide (SiC), alumina (AL2O3) are used to improve the material properties of polymers and in general are considered to be highly potential fillers. However, questions concerning the proper type and amount of CNTs, e. g., single-wall CNTs (SWCNT), double-wall CNTs (DWCNT), or multi-wall CNTs (MWCNT) and other nanoparticles such as silicon carbide, alumina and their influence are still to be answered. This work studies the effect of the amount and types of nanofillers on the mechanical properties of epoxy based nanomaterials and their functionalization. In the present work, epoxy resin was modified with different types of nanofillers including SWCNT, DWCNT, MWCNT, SiC and AL2O3. The amount of CNTs (SWCNT, DWCNT and MWCNT) used for each type of CNTs were 0.1, 0.3 and 0.5 wt.-%. By contrast, the amount used for (SiC), and (Al2O3) measured 0.5, 1 and 1.5 wt.-% for each type. Tensile test were conducted for each group to investigate the m...

Surface-Modified Garnet Particles for Reinforcing Epoxy Composites

The present study investigated the tribological performance of epoxy (EP) matrix composites enhanced with natural garnet. The garnet was surface-modified with sodium stearate for optimal performance. Composites comprising different contents and particle sizes of modified garnet (MG) were prepared with a mixture of EP and MG. The sodium stearate-bonded garnet and EP formed a stable structure. Tribological performance was measured by a ball-on-plate apparatus under permanent dry sliding conditions and a wear track was obtained by an optical profilometer. The wear mechanism was explored by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) images. Wear test results showed that the coefficient of friction for all EP/MG composites decreased compared with that for neat epoxy. The results also indicated that the addition of MG can evidently improve the tribological properties of EP matrix composites.

Improving the properties of epoxy/melon shell bio-composites: effect weight percentage and form of melon shell particles

Increased environmental awareness and consciousness throughout the world have developed an increasing interest in natural fibers/particles and their applications in various fields. Based on the forgoing, improving the properties of epoxy/melon shell particles was investigated. The melon shell particles used were uncarbonized (UCMSp) and carbonized (CMSp). The composites were produced by the hand-laying method. The melon shell particles varied from 5 to 30 wt% with 5 wt% interval. The microstructure was analyzed using scanning electron and atomic force microscope. The properties tested were density, tensile strength, compressive strength, impact energy, capacitance and dielectric strength. The results of impact energy are 4.5, 5.0 and 5.62 J; tensile strength: 3.7 13.7 and 15.6 N/mm2 obtained at 0 wt% and at 20 wt%; elastic modulus: 456, 1250 and 1320 N/mm2; and dielectric constant: 5.5, 15.7 and 18.9 obtained at 0 wt% and at 30 wt% for pure epoxy, UMSp and CMSp, respectively. The tensile strength, elastic modulus and impact energy of the epoxy/CMSp composites show higher values than epoxy/UCMSp. The work has established that melon shell particles can be used for increasing the mechanical and electrical properties of epoxy matrix composites for indoor and outdoor applications.

Effect of Unidirectional and Woven Fibers on Impact Properties of Epoxy

The main aim of this study is to investigate the Impact properties of Epoxy matrix composites by a drop weight impact tester using spherical steel projectile with five different ranges of heights. Three different types of reinforcement were used in the experimental works: woven glass, woven glass+carbon, unidirectional carbon. This study showed that reinforcing epoxy with unidirectional and woven carbon and glass improves the impact properties. Minimum deformation and maximum force and energy were in woven glass reinforced epoxy, while unidirectional carbon reinforcement showed low impact energy absorption and high deformation and failure in a very short time compared with others due to susceptibility to impact damage while the impact strength of hybrid carbon+glass is higher than carbon composites because glass fibers add additional resistance to impact and damage.