Epoxy-based Composite Materials Research Articles

Eggshell bio-derived hydroxyapatite particle-wool/polyester staple fibers hybrid reinforced epoxy bio-composites for biomedical services

This study assessed the impact of hybrid reinforcement from natural and synthetic materials on the wear and mechanical properties of epoxy-based composite materials needed for biomedical applications. Hydroxyapatite was synthesized from eggshells using the hydrothermal method, while wool fiber was obtained from cow hair. The hybrid reinforced composites were developed by blending hydroxyapatite particles and the fibers by hand layup method in an open mold production process, with specified amounts of 3–15 wt % reinforcement. The characterized properties included tensile and flexural strengths, impact energy, wear resistance, and hardness. A scanning electron microscopy study was conducted to analyze the adhesion between the matrix and reinforcements at the interface, providing valuable insights into the overall integrity of the composites. The results showed a significant increase in the properties of the hybrid reinforced composites when compared with the pristine sample. In particular, the 6 wt% reinforced composite enhanced 61.14 % in tensile strength and 160.79 % enhanced 61.14 % in tensile strength and 160.79 % in flexural strength. Thus, the study shows that substituting synthetic fibers with hybrid organic-based reinforcement offers a viable approach for developing sustainable materials with improved mechanical properties suitable for biomedical applications.

Optimized Proportioning Techniques and Roadway Performance Evaluation of Colored Asphalt Pavement Materials

This study systematically investigated the formulation optimization, performance evaluation, and practical application of epoxy-based composite materials for colored asphalt pavement. By conducting comprehensive experiments, we optimized the composition of epoxy-based composites, verifying their excellent bonding performance, good heat resistance, and UV aging resistance under various temperature conditions. The key optimized component ratios were determined as a 1:1 blend of Type I and Type II epoxy resins, 30 phr of curing agent, 10 phr of toughening agent, 5 phr of diluent, 10% filler, 12% flame retardant, and 10% pigment. At the recommended dosage of 2.0 kg/m2 of epoxy binder, the composite structure exhibited the best reinforcement effect, improving low-temperature performance significantly. Compared to ordinary asphalt mixtures, the colored pavement composite structure showed superior mechanical strength, deformation capacity, high-temperature stability (dynamic stability approximately three times higher), and water stability (TSR values up to 95.5%). Furthermore, its fatigue life decay rate was significantly lower, with fatigue limit loading frequencies more than three times those of ordinary asphalt mixtures, demonstrating excellent fatigue resistance. This study provides strong technical support and a theoretical basis for the development and practical application of colored asphalt pavement.

Preparation and Characterization of Epoxy-Based Composite Materials Reinforced with Graphene Oxide

In this study, modified graphene oxide (GO) with γ-APS silane coupling agent before being dispersed into an epoxy/4,4’-diamino diphenyl methane matrix to prepare a composite material using the bar-coating technique. The modified GO materials with the γ-APS silane (GOS) were characterized by infrared spectrum, Zeta potential, and TG/DSC thermal analysis. The amount of silane grafted on the GO is ~ 3.3 wt.%; the Zeta potential value shifted from the negative to the positive region was observed on the surface potential distribution diagram. Scanning electron microscopy, DSC thermal analysis, and dielectric constant were used to characterize the obtained composite epoxy/GO material properties. The results show that graphene oxide, after modification with γ-APS silane agent, has good dispersion ability in the epoxy resin matrix. Composite material epoxy/GOS presented a high dielectric constant value (εaverage = 6.19, at 1 kHz), increasing thermal stability, which is a suitable material promising for future applications.

Injecting Sustainability into Epoxy-Based Composite Materials by Using Bio-Binder from Hydrothermal Liquefaction Processing of Microalgae.

We report a transformative epoxy system with a microalgae-derived bio-binder from hydrothermal liquefaction processing (HTL). The obtained bio-binder not only served as a curing agent for conventional epoxy resin (e.g., EPON 862), but also acted as a modifying agent to enhance the thermal and mechanical properties of the conventional epoxy resin. This game-changing epoxy/bio-binder system outperformed the conventional epoxy/hardener system in thermal stability and mechanical properties. Compared to the commercial EPON 862/EPIKURE W epoxy product, our epoxy/bio-binder system (35 wt.% bio-binder addition with respect to the epoxy) increased the temperature of 60% weight loss from 394 °C to 428 °C and the temperature of maximum decomposition rate from 382 °C to 413 °C, while the tensile, flexural, and impact performance of the cured epoxy improved in all cases by up to 64%. Our research could significantly impact the USD 38.2 billion global market of the epoxy-related industry by not only providing better thermal and mechanical performance of epoxy-based composite materials, but also simultaneously reducing the carbon footprint from the epoxy industry and relieving waste epoxy pollution.

On the fatigue behaviour of epoxy-based nanostructured composite materials

Epoxy composites and nanocomposites enable the creation of high-performance structures and innovative designs. However, there is limited research focused on their fatigue characterization. The purpose of this study is to analyze the fatigue resistance results of nanostructured composite materials made with an epoxy matrix of Diglycidyl Ether of Bisphenol F and 9,9-bis(3-chloro-4-aminophenyl) fluorine (DGEBF-CAF) reinforced with 5%wt of elastomeric nanoparticles with an average diameter of 200 nm. The tests are conducted at variable load and frequency using Rotating Bending (R-B) and Tensile-Tensile (T-T) tests, and the results are compared to those obtained with pure resin. The occurrence of thermal fatigue phenomena during the tests is monitored using a thermal camera. The results confirm that pure epoxy resin exhibits poor crack propagation resistance due to its low ductility and toughness, and the introduction of a second phase leads to an improvement of approximately 3 times in T-T tests and 5 times in R-B tests.

In-situ growth of diamond/Ag as hybrid filler for enhancing thermal conductivity of liquid crystal epoxy

To meet the higher requirements posed by high-power chips on packaging materials, designing and fabricating a multi-functional integrated composite is an effective solution. In this work, the diamond/Ag hybrid filler was prepared (in-suit growth) using the “Ball milling-Heating” approach in the absence of any solvent or external force. Furthermore, the nano-micro hybrid filler was combined with the inherently high thermal conductivity liquid crystal epoxy resin to create composites through a hot-press curing. In this process, there is a synergistic interaction between fillers and matrix and Ag nanoparticles serve as bridging elements in nano-scale. Ultimately, the hybrid filler with a nano-microstructure effectively constructs “phonon-electronic-phonon” pathways in the liquid crystal epoxy matrix. When the hybrid filler content reached 80 wt%, the composites demonstrated a range of integrated advantages including high thermal conductivity (4.65 W/m·K), low coefficient of thermal expansion (CTE), high volume resistivity, and excellent thermal stability. The era of high-power devices is approaching, and this study offers a novel perspective on the application of epoxy-based composite materials in the realm of advanced packaging.

A novel microwave-based non-destructive testing system for detection of sub-surface defects in natural flax fiber reinforced composite material

In the work presented here, microwave non-destructive testing using a rectangular waveguide loaded with a novel planar unit cell filter for the inspection of defects in the composite is studied. The proposed planar filter is designed as a unit cell with a copper (annealed) microstrip component on an FR-4 substrate. The waveguide loaded with the planar filter exhibits a reflection coefficient of −35.919 dB at a frequency of 10.548 GHz. This planar filter waveguide is used as the sensor probe for the non-destructive testing method proposed here and is aimed to increase the sensitivity by measuring the differences in permittivity of materials. Computer simulation technology software (CST studio suite) is used for implementing the design, simulation, and material/defect evaluation. The defects studied are voids, cracks, and delamination in an epoxy-based natural flax fiber-reinforced composite material. The performance-improved microwave sensor probe is used to pick up permittivity variations in the presence of defects in lax-based natural fiber-reinforced composite material.

Novel epoxy-based biocidal composite material filled with polylactide-capsulated copper (I) oxide particles

Novel epoxy-based biocidal composite material filled with polylactide-capsulated copper (I) oxide particles

Mechanical Properties of a Bone-like Bioceramic-Epoxy-Based Composite Material with Nanocellulose Fibers.

Several composite materials are being investigated as reinforcement fillers for surgery simulations. This study presents an artificial composite material with properties similar to those of the human bone, which may be used in surgery simulations. Moreover, considering the potential toxicity of debris generated during sawing, a safe epoxy-based composite material was synthesized using cellulose nanocrystals (CNCs) and bioceramics (i.e., hydroxyapatite, Yttria stabilized zirconia oxide, Zirconia oxide), which were used to mimic the stiffness of human bone. To examine the change in mechanical properties according to the composition, 1, 3, and 5 wt% of CNCs were mixed with 5 wt% of the bioceramics. When CNCs were added at 1 wt%, there was a confirmed change in the non-linear stiffness and ductility. The CNC-added specimen fractured when forming a nano-network around the local CNCs during curing. In contrast, the specimen without CNCs was more densely structured, and combined to form a network of all specimens such that a plastic region could exist. Thus, this study successfully manufactured a material that could mimic longitudinal and transverse characteristics similar to those of real human bone, as well as exhibit mechanical properties such as strength and stiffness. Bioceramics are harmless to the human body, and can be used by controlling the added quantity of CNCs. We expect that this material will be suitable for use in surgery simulations.

Recycling of carbon fiber reinforced polymers in a subcritical acetic acid solution

A novel single-stage solvolysis process is demonstrated for recycling carbon fibers from an epoxy-based composite material using 50 wt% acetic acid solution under subcritical conditions. The process yields 100% fiber recovery efficiency in less than 30 min at 300 °C. Qualitative SEM/EDS analysis of the fibers reveals that the recovered fibers are entirely free of resin, and the carbon fiber surfaces were not damaged. SEM images and gravimetric measurements of the composites treated at lower temperatures and short residence times show an initial increase in mass of the CFRP samples, suggesting a two-step process consisting of initial composite swelling due to uptake of solvent, followed by depolymerization and chemical decomposition of the polymer. FTIR and GC-MS analyses confirm resin decomposition and production of aromatic and aliphatic compounds.

Study the Susceptibility of Epoxy-based Composite Materials Reinforced with Powders of Different Elements and Compounds to be used as Materials with a Positive Environmental Impact

In this research, a group of polymeric composite materials with an epoxy basis (PMCS) was manufactured, the base material is (Master Brace ADH 1406 Part A), which represents a substance (Resin) and (Master Brace ADH 1406 Part B) is a (Hardener), with the standard mixing ratio of material [1H:3R]: this material supported the basis with powders of different materials (Al2O3, Black Carbon, Active Carbon, kaolin, Car Exhausts Type I, II and III). The manufactured samples have been subjected to hardness and impact resistance tests. The results showed that there is an improvement in the surface hardness and the shock resistance of the base material after reinforcement it with different powders. The results also showed that there is a critical ratio for the amount of the reinforcing material, which shows the best case of improvement in the mechanical properties and it depends on the nature of the base material. The results also showed that the samples of the substrates reinforced with different powders showed their ability to adsorb nine elements or compounds from the hypothetical system that were subjected to it for a period of (30 days), and that the most basic materials that showed the content of the adsorbed elements was the substrate fortified with powder (Black Carbon) and the least It is the base material supported by powder (Al2O3), and the base materials supported by powder (Active Carbon) are less efficient in the adsorption of elements and compounds than (Black Carbon), in addition, the base materials supported by powders of materials used in car exhausts and of their three types have a limited ability in Adsorption of elements and compounds.

Investigation of the properties of composite materials based on epoxy resins with microsilica additives

The outcomes of studying epoxy-based composite materials supplemented with microsilica are provided in the article. Microsilica was used as a filler. The samples were produced on the epoxy ED-20 basis supplemented with 2, 5 and 10 mas. % of microsilica. The structure and size of finely dispersed filler particles were defined. The obtained composites were tested for resistance to the effect of variable temperatures, corrosive, and abrasion. The study outcomes proved that samples supplemented with 2% of microsilica are more resistant to acid and alkali as well as to petrol than those ones supplemented with 25% of microsilica. Besides the amount of the filler from 2 to 10% doesn’t sufficiently affect the resistance to variable temperatures. When microsilica is added to epoxy resin, it causes scuff resistance increase. The conducted testing proved that the developed composite materials are resistant to the effect of variable temperatures, corrosive, and abrasion. This enables to use these materials as coatings and anti-corrosion protection during machine maintenance.

Development and Analysis of the Physicochemical and Mechanical Properties of Diorite-Reinforced Epoxy Composites.

The aim of this paper is to study the effect of a polyfunctional modifier oligo (resorcinol phenyl phosphate) with terminal phenyl groups and a dispersed mineral filler, diorite, on the physicochemical and deformation-strength properties of epoxy-based composites. The efficiency of using diorite as an active filler of an epoxy polymer, ensuring an increase in strength and a change in the physicochemical properties of epoxy composites, has been proven. We selected the optimal content of diorite both as a structuring additive and as a filler in the composition of the epoxy composite (0.1 and 50 parts by mass), at which diorite reinforces the epoxy composite. It has been found that the addition of diorite into the epoxy composite results in an increase in the Vicat heat resistance from 132 to 140–188 °C and increases the thermal stability of the epoxy composite, which is observed in a shift of the initial destruction temperature to higher temperatures. Furthermore, during the thermal destruction of the composite, the yield of carbonized structures increases (from 54 to 70–77% of the mass), preventing the release of volatile pyrolysis products into the gas phase, which leads to a decrease in the flammability of the epoxy composite. The efficiency of the functionalization of the diorite surface with APTES has been proven, which ensures chemical interaction at the polymer matrix/filler interface and also prevents the aggregation of diorite particles, which, in general, provides an increase in the strength characteristics of epoxy-based composite materials by 10–48%.

Enhancement for Mechanical Properties of Green Composites Using Treated Yellow Bamboo

Bamboo is a natural material with a very light density compared to steel. The bamboo can replace steel to reinforce concrete or composite materials in construction. In this study, the bamboo was treated by chemical process through two steps: (1) NaOH and Na2SO3 mixture, (2) H2O2 solution. The results showed that the color of the extract and the lignin content were significantly influenced by the extraction time and the concentration of chemicals used. Similarly, in terms of the mechanical properties of the epoxy-based green composite material, there was an improvement on the values of flexural and compressive strength for the composite reinforced the treated bamboo. Research results show the potential applications of bamboo to gradually replace fiberglass in green structures, safe for humans and environmentally friendly.

Research of Casting Moulding of Epoxy Resin Composites Reinforced with High-Strength Fibres during the Manufacturing Operations

In general, epoxy resins are known for their excellent adhesion, chemical and thermal resistance, unique mechanical properties and excellent electrical insulators. The various fibres are incorporated into epoxy resin matrix materials. With the prepared samples, the fibre tests are passed. The results of the investigation are also taken into account due to the strength of the connection between the fibre and the matrix. The aim of our research is the preparation and subsequent testing of epoxy-based composite materials during their manufacturing operations, specifically by casting technology. The properties of fibre-reinforced composites depend significantly on the choice of fibre and matrix, and how they are combined, the fibre-matrix ratio, the fibre length, its orientation, the thickness of the composite and the presence of a bonding agent to improve fibrematrix bonding.

Understanding the Solid–Ice Interface Mechanism on the Hydrophobic Nano-Pillar Structure Epoxy Surface for Reducing Ice Adhesion

Ice accumulation on wind turbine blades reduces power generation efficiency and increases wind turbines’ maintenance cost, even causing equipment damage and casualties. In this work, in order to achieve passive anti-icing, a series of nano-pillar array structures with different diameters of from 100 to 400 nm and heights of from 400 to 1500 nm were constructed on the substrate bisphenol-A epoxy resin, which is generally used in the manufacturing of wind turbine blades. The as-constructed functional surface showed excellent water repellence, with a contact angle of up to 154.3°. The water repellence on the nano-pillar array structures could induce ultra-low ice adhesion as low as 7.0 kPa, finding their place in the widely recognized scope of icephobic materials. The underlying solid–ice interface mechanism was well revealed in regard to two aspects: the interface non-wetting regime and the stress concentration behavior on the nano-pillar array structured surface. A detailed discussion on both the factors presented here will help surface structure design and function of icephobic materials, especially for epoxy-based composite materials.

Thermal properties and degradation kinetics of epoxy-γ-alumina and epoxy-zinc oxide light weight composites

Lightweight composite materials are the gold standard in aeronautical and aerospace applications due to their strength and low mass. To carry higher payloads and decrease launching costs, nanosatellites lightweight. Additionally, nanosatellites must also resist high thermal radiation loads while working in orbit. Polymer-based composite materials maintain low mass and added reinforcing ceramic fillers contributes to increasing radiation resistance, thus producing composites that meet both requirements. In this work, the effects of γ-alumina (Al2O3) and zinc oxide (ZnO) micro- and nanoparticles on the thermal properties and degradation kinetics of epoxy-based composites were investigated. The effective thermal conductivity improved up to 17.8 % for epoxy/γ-Al2O3 and 27.4 % for epoxy/ZnO. The effective thermal diffusivity values show a monotonic decreasing behavior as a function of the particle concentration for the epoxy/γ-Al2O3 composites; for the epoxy/ZnO composites, no correlation on the effective thermal diffusivity values with the ZnO-content was observed. Both oxide-based ceramic fillers increase the thermal stability of epoxy up to 250 °C; however, γ-Al2O3 decreased the maxima decomposition temperature of the epoxy matrix by 6°C. Zinc oxide did not affect the maxima decomposition temperature but decreased the activation energy of epoxy by ~ 45 %. These results provide a feasible manufacturing method for epoxy-based composite materials (i.e. nanosatellites) where efficient heat transfer, heat resistance, and low mass are required.

Formation of the Structure and Properties of Epoxy-Based Composite Materials

Over the past fifteen years, Russian and foreign scientists have conducted a large amount of research in the development and use of composite materials based on epoxy resins, including the ways to restore structural integrity. In the oil and gas industry, composite materials are used for repair works.

Destruction of Epoxy-Based Composite Materials under the Influence of Impact Load

Some features of impact destruction are shown on the example of a composite material with epoxy matrix and hybrid filler, magnetic particles of iron oxide of micron size and nanoparticles of iron oxide are used in the capacity of it. Dependence of the impact viscosity of the material on the temperature was discovered experimentally, which demonstrates the increase of this value at the decrease of the temperature.

Resin injection behavior in process of manufacturing insulation spacer with permittivity gradient using computational fluid dynamics

The advent of new technology for designing insulation materials with desired properties stimulates our interest in development of insulation spacers in gas-insulated switchgear (GIS). Tailoring of two kinds of epoxy-based composite materials (resins) with different relative permittivities enables development of insulation spacers with graded permittivity that decrease the diameter of a GIS tank. Computational fluid dynamics for the resin injection process based on the properties of resin mixtures at various mixing ratios between two resins with high/low relative permittivity enables us to estimate the injection behavior and distribution of resins in the manufacturing of insulation spacers. Simulation results demonstrated the gradient of resins in the insulation spacers by this resin injection method using two resins. In particular, the insulation spacer formed by two or four injection inlets have a more favorable distribution of resins than that achieved by one injection inlet.