Epoxy Matrix Research Articles

Investigation of the Thermal and Mechanical Properties of Glass Fiber Reinforced ABS/Epoxy Blended Polymer Composite

This research investigates the formation of polymer blends by blending Epoxy LY556 with Acrylonitrile-Butadiene-Styrene (ABS) at weight percentages ranging from 2 to 10% wt. The thermal properties, morphological characteristics, tensile strength, flexural strength, and interlaminar shear strength (ILSS) characteristics of these composites were examined. The X-ray Diffractometer (XRD) and Fourier Transform Infrared Spectrometer (FTIR) studies confirmed the presence of binary blends. The miscibility of epoxy/ABS blends is shown by the presence of a single melting peak in the Differential Scanning Calorimetry (DSC) analysis. The Thermogravimetric Analysis (TGA) findings indicate that epoxy and ABS blends exhibit greater thermal stability than pure epoxy. The tensile strength increased from 183.6 to 380.6 MPa, flexural strength increased from 165.3 MPa to 335.6 MPa, ILSS increased from 32.4 MPa to 72 MPa for 8% wt. of ABS blending, and the laminates witnessed a decrease in density and hardness values. The Scanning Electron Microscopy (SEM) images demonstrate the commendable blending characteristics and the synergistic impact of the ABS/Epoxy composite, yielding superior outcomes to the pure epoxy material.

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

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

A facile approach for enhancing mechanical resilience, and corrosion protection in epoxy coatings using bismuthene nanosheets

AbstractThis study presents novel mechanochemical methods for the synthesis and chemical modification of bismuthene nanosheets (BINS) using a high‐speed blender and planetary ball milling. Atomic force microscopy (AFM) measurements confirmed successful exfoliation of 1.5‐nm BINS. Epoxy/BINS nanocomposites exhibited enhanced mechanical properties, thermal stability, and chemical resistance. Chemical modification via ball milling improved the interface and dispersion of BINS within the epoxy matrix, leading to significant enhancements in mechanical performance and chemical resistance. Compared to neat epoxy, at 0.75 vol% m‐BINS, Young's modulus, impact strength and fracture toughness KIC were respectively enhanced by 30%, 88.6%, and 144.4% while these increments were 10%, 55.7%, and 97.8% for pristine BINS‐based epoxy nanocomposite. A 3D finite element model of the impact test of the nanocomposite was developed to predict its behavior under high‐strain rate loadings; the numerical model showed high agreement with experimental measurements. Epoxy/m‐BINS nanocomposites demonstrated exceptional chemical resistance, attributed to the small lateral dimensions of m‐BINS, which fill the spaces between cross‐linked epoxy molecules and uniformly distribute within the matrix. These findings highlight the crucial role of interface and dispersion in defining the mechanical properties of nanocomposites. Overall, this study provides a facile and scalable method for synthesizing and modifying bismuthene, showcasing its potential for developing functional polymer nanocomposites.Highlights Bismuthene nanosheets & modified BINS (m‐BINS) are prepared by eco‐friendly method. m‐BINS is ~1.5 nm thick and ~0.5 μm wide. m‐BINS shows good dispersion and strong interface adhesion within epoxy matrix. Impact strength and KIC of epoxy/m‐BINS nanocomposite are enhanced by 88.6% and 144.4%. Numerical model for impact strength is developed to predict behavior at high‐strain rate.

A length-free phase field model for epoxy adhesive materials based on modified Drucker–Prager criterion

Characterizing the cracking behavior of epoxy adhesive material is of great importance for composite structures. Recently, the phase field model has emerged as the preferred method for predicting the crack propagation. This paper presents a length-free phase field model considering the characteristics of epoxy adhesive materials. The proposed model is formulated within a framework that decomposes the phase field fracture driving force, ensuring that it adequately considers the tension/compression asymmetry of the epoxy adhesive materials. The effects of hydrostatic pressure, deviational stress, and friction are incorporated into the model by employing a modified Drucker-Prager failure criterion. The failure criterion is included in the phase field model using the effective stress invariants. Furthermore, the internal length scale, previously considered to lack real physical meaning, is reformulated based on material strength. This model addresses the challenge of measuring the internal length of epoxy materials. It serves as a valuable reference for applying phase field models to epoxy materials. The accuracy of the model is validated through an L-shaped plate simulation, and an attempt using the model to predict the crack development in thick epoxy adhesive joints is undertaken. Several representative samples are simulated, including three double cantilever beams with different configurations. The numerical results demonstrate a good correlation with experimental data, highlighting the potential of the model in simulating the crack propagation in epoxy adhesive joints.

Pre-structural patterning approach for enhancing flow characteristics of B-stage film-type epoxy molding compound

Epoxy molding compound (EMC) compositions of silica powder and epoxy matrix have been utilized as encapsulation for semiconductor packaging over the past decades. Among various forms of EMC, film-type EMC offers untapped potential. Utilizing EMC film as an encapsulation material allows larger and more uniform encapsulation behavior especially for panel-level and wafer-level packaging applications. In material aspects, as increases silica contents in EMC film, it can encounter a trade-off relationship between the coefficient of thermal expansion (CTE) and the material's viscosity. As silica content increases, the CTE tends to decrease, which enhances warpage behavior. However, viscosity also tends to increase, which reduces flowability. To overcome these tradeoff relationships, in our study, we have demonstrated a pre-structural patterning approach to enhance flowability of B-stage EMC film without changing the raw compositions of material. By doing that, we can suppose increased flowability of film while having similar thermomechanical properties. For patterning while maintaining B-stage, patterned protection film was fabricated using a brass-based metallic mold and a PDMS/PUA-based soft mold. Subsequently, pre-structural patterned EMC was fabricated by transferring the patterned protection film onto a B-stage EMC film using a laminator. The effectiveness of patterning on EMC film was investigated in both numerical and experimental molding analysis according to rheological, chemical, and thermomechanical characterization. The pre-structural patterning approach demonstrated enhanced flow characteristics via a shortened flow path despite the increased viscosity caused by higher silica content.

Influence of hybrid nanofiller on elastic behavior and stiffness of basalt/E-glass MWCNTs/SiO2 hybrid nanocomposites

Sustainable material development techniques help in finding and employing sustainable materials without compromising quality. Composite materials are crucial in structural design, automotive manufacture, and aeronautical engineering. Advanced materials that use reinforcement and filler ingredients must be developed strategically to improve strength and performance. Hence, this study develops hybrid nanocomposites with hybrid nanofillers (MWCNTs and SiO2) and hybrid fibers (basalt and E-glass) and optimizes the competition to maximize elastic behavior and stiffness. Using a hand layup approach, composite samples were made by altering mass fractions of two filler materials (0%, 1%, 1.5%, and 2% by weight) and epoxy matrices (40%, 38%, 37%, and 36%). Shore D hardness and dynamic mechanical analysis (DMA) were used to evaluate the composites. The storage modulus, loss modulus, and damping coefficients are examined using DMA. Specifically, the largest storage modulus is 4.86 × 1010 Pa at 61 °C, while the peak loss modulus is 1.01 × 1010 Pa at 80 °C. The highest damping coefficient is 0.25. Note that 1.5% MWCNTs and SiO2 filler materials independently contribute to the excellent storage and loss modulus. However, an outstanding damping coefficient was achieved without filler materials. The highest achieved shore D hardness value is 88. Filler materials are used to achieve this high hardness.

Fabrication of ramie/hemp fibers-reinforced hybrid polymer composite—A comprehensive study on biological and structural application

This study primarily investigates the antibacterial properties, tensile strength, flexural strength, impact strength, hardness, and microstructural characteristics of a composite, utilizing Scanning Electron Microscopy (SEM) for detailed analysis. The composite, crafted through a hand layup technique, optimally blends ramie and hemp fibers within an epoxy matrix. Its antibacterial efficacy was rigorously tested against common bacterial strains, demonstrating significant potential for medical and hygienic applications. The evaluation of tensile strength revealed the composite’s enhanced capability to withstand longitudinal stresses, with a peak strength of 37.81 MPa, achieved by increasing ramie fiber content. In addition, a flexural strength of 39.72 MPa underscored the material’s robust resistance to bending forces, crucial for structural uses. The composite’s impact strength, accessed via the Izod impact test, registered at 0.021 J/m2, indicating its ability to absorb and dissipate energy upon sudden impacts, making it ideal for automotive and protective gear applications. The Rockwell hardness test further quantified the composite’s resistance to surface indentation, vital for wear-resistant surfaces. SEM analysis offered a comprehensive view of the microstructural dynamics between the fibers and the matrix, especially under tensile stress, highlighting the intricacies of fiber–matrix adhesion, crack propagation, and overall composite integrity. Notably, the antibacterial properties were confirmed by an 18 mm inhibition zone, which showcases the composite’s ability to inhibit bacterial growth effectively.

Designing a high barrier, tough and self-repairing epoxy composite coatings with Ce-MOF decorated 2D α-ZrP smart nanofiller

Synergistical passive barrier enhancement and active self-healing has been an emerging tactic for developing prominent anti-corrosion coatings. Herein, a cerium/2-methylimidazole metal-organic framework (Ce-MOF) was that is in-situ grown on ultrathin α-ZrP nanosheets with outstanding dispersibility. The parallel arrangement of α-ZrP-based nanosheets within the epoxy matrix was driven by shear force from blade-coating technology optimizing the coating's physical barrier and self-repairing capability. This advancement may herald a new era in designing smart coatings and offering potent protection against diverse corrosion types such as filiform corrosion.

Terminal Chlorine Affected the Short-Term Electrical Properties of Epoxy Resin Materials

Terminal Chlorine Affected the Short-Term Electrical Properties of Epoxy Resin Materials

Nanocomposites for Load‐Bearing Structures Heatable Through Joule Heating

AbstractEpoxy resin based on carbon nanotubes with heating properties is studied to tune its heating performance by changing the applied voltage value. The developed self‐heating device, able to heat to high temperatures in a short time, can be applied in various areas. The electro‐thermal investigation shows the presence of both positive temperature coefficient (PTC) and negative temperature coefficient (NTC) behaviors with a predominance of NTC trend neat to the glass transition temperature of the epoxy matrix.

Enhanced mechanical, thermal properties and thermal conductivities of epoxy composites via incorporating graphene oxide‐grafted carbon nanotubes hybrids

AbstractA hetero‐structured hybrid was produced by grafting one‐dimensional (1D) amine‐functionalized multiwalled carbon nanotubes (MWCNTs) onto the basal plane of two‐dimensional (2D) graphene oxide (GO) via an amine‐epoxy ring‐opening reaction, and such hybrid was further applied for reinforcing epoxy composites. Based on this hybrid design, 1D MWCNTs anchored on the 2D GO nanosheets resisted the re‐stacking of GO nanosheets while GO improved the MWCNTs' dispersion state. Attributing to the synergistic effect of GO and MWCNTs, a multi‐dimensional conducting network within epoxy matrix was constructed and efficiently transferred stress and heat between hybrid and matrix. When just 0.5 wt% hybrids were incorporated, the mechanical properties, thermal stability and thermal conductivity of hybrid‐filled epoxy composites were significantly improved, compared with pure epoxies. This work gives a promising method for designing and preparing polymer composites for thermal management and protection applications.Highlights A hetero‐structured hybrid consisting of MWCNTs and GO was obtained. Better dispersion of GO–MWCNTs within matrix was achieved. A multi‐dimensional GO–MWCNTs conducting network in matrix was constructed. Enhanced properties were due to the synergistic effect of GO and MWCNTs. Structural performance of GO and MWCNTs was maximized.

Experimental Design and Analysis of MWCNT, Nanoclay and Zinc Oxide Nanofillers on Bi-directional-Chopped Stranded Glass Fibre Reinforced Epoxy matrix on Mechanical Properties using Multi Response Performance Index Approach

Experimental Design and Analysis of MWCNT, Nanoclay and Zinc Oxide Nanofillers on Bi-directional-Chopped Stranded Glass Fibre Reinforced Epoxy matrix on Mechanical Properties using Multi Response Performance Index Approach

A Novel Route to Glass Fiber‐Reinforced Epoxy Matrix Composites: Visible Light Activated Radical Induced Cationic Frontal Polymerization

AbstractIn the current study, a novel radical‐induced cationic frontal polymerization (RICFP) concept capable of rapid curing at room temperature via visible light irradiation is represented. Initially, the optimal formulation, which can be most effectively cured with visible light irradiation, is determined based on thickness, hardness, curing speed, and mechanical properties using FT‐IR, DSC, TGA, and flexural test methods. Subsequently, the viability of the method is illustrated by fabricating glass fiber‐reinforced composites through the hand lay‐up technique, employing the optimized formulation and glass fibers in various forms (chopped strand mat and biaxial). Mechanical properties of the obtained composites, including bending, tensile, and shear tests, are carried out according to relevant international standards and compared with reference composites thermally cured with amine‐based hardener by conventional method.

Enhancing the mechanical properties of CF-reinforced epoxy composites through chemically surface modification of carbon fibers via novel two-step approach by addition of epichlorohydrin

The chemical surface modification was carried out in this study to improve the interface connection between carbon fiber (CF) and epoxy matrix to study the mechanical and fracture behavior of CF-reinforced epoxy composites. Finite element analysis was carried out by using ABAQUS software to simulate the variation of the tensile strength (TS), interfacial shear strength (IFSS), and interlaminar shear strength (ILSS). The chemical surface modification was carried out by the chemical oxidation by nitric acid and subsequently, addition of monomer resin of epichlorohydrin in a solution at 80 °C. The Raman spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy were carried out to ensure the successful surface modification of CFs. Subsequently, surface-modified CF-reinforced epoxy composites were prepared through the hand lay-up method with the volume fraction of 20 wt.%, and curing was carried out at 80 °C for 4 h. The TS, IFSS, and ILSS values equaled 462.82 MPa, 156 MPa, and 4.1 MPa for modified CF/epoxy composites were achieved, respectively, which are improved remarkably compared to unmodified ones (380, 81, and 2.9 MPa). These improvements are attributed to the successful surface modification of CFs by epichlorohydrin. The surface modification causes the increase in wettability of CFs and the formation of mechanical interlocking and interaction between CFs and epoxy matrix was achieved through uniform and homogenous distribution of epichlorohydrin on the surface of CFs. Fractography was carried out, which indicated the sound and uniform adhesion between CF and epoxy matrix. Achieved results are consistent with simulated results.

Preparation and characterization of ox bone powder and bamboo fibers reinforced hybrid epoxy composites

Composite materials are one of the fastest growing when compared with metal, ceramic, and polymer due to their high specific strength, stiffness, and versatile application in various fields. This study aimed to develop an ox bone powder and bamboo fiber-reinforced hybrid epoxy composite for stock and bumper applications and investigate the effect of the reinforcements on the composite’s mechanical properties. The reinforcements used in this work were random orientations of animal bone (ox) powder of 75 microns and bamboo fiber. The matrix used for this work was epoxy resin. Composite materials were prepared using the hand layup method with a 40% weight fraction of reinforcement (bone powder and bamboo fiber) and a 60% weight fraction of epoxy resin matrix. Five different combinations of bone powder and bamboo fiber with a fixed amount of epoxy resin were used for this work. The combinations of bamboo fiber and bone powder were: 40% bamboo fiber with 0% bone powder; 30% bamboo fiber with 10% bone powder; 20% bamboo fiber with 20% bone powder; and 0% bamboo fiber with 40% bone powder. The mechanical properties studied were compressive strength, impact strength, and flexural strength. In addition, water absorption was studied for all combinations. The maximum results of the flexural and impact strengths were 278.91 MPa and 7.5 J/m, respectively, at a 0:40 (bone powder: bamboo fiber) composite. The maximum compressive strength and the lowest absorption obtained were 283.3 MPa and 1.05%, respectively, at the 40:0 (bone powder: bamboo fiber) composite. For the hybrid composite case, optimal flexural and impact strengths were 236.72 MPa and 6.66 J/m, respectively, and water absorption was 1.52% at 10:30 (bone powder: bamboo fiber). Since reasonable flexural strength, impact strength, and water absorption were obtained with the hybrid composite of 10:30 (bone powder: bamboo fiber), this combination of the hybrid composite is recommended for stock and bumper applications.

The Effect of Carbon Nanofibers on the Mechanical Performance of Epoxy-Based Composites: A Review.

This review is a fundamental tool for researchers and engineers involved in the design and optimization of fiber-reinforced composite materials. The aim is to provide a comprehensive analysis of the mechanical performance of composites with epoxy matrices reinforced with carbon nanofibers (CNFs). The review includes studies investigating the static mechanical response through three-point bending (3PB) tests, tensile tests, and viscoelastic behavior tests. In addition, the properties of the composites' resistance to interlaminar shear strength (ILSS), mode I and mode II interlaminar fracture toughness (ILFT), and low-velocity impact (LVI) are analyzed. The incorporation of small amounts of CNFs, mostly between 0.25 and 1% by weight was shown to have a notable impact on the static and viscoelastic properties of the composites, leading to greater resistance to time-dependent deformation and better resistance to creep. ILSS and ILFT modes I and II of fiber-reinforced composites are critical parameters in assessing structural integrity through interfacial bonding and were positively affected by the introduction of CNFs. The response of composites to LVI demonstrates the potential of CNFs to increase impact strength by reducing the energy absorbed and the size of the damage introduced. Epoxy matrices reinforced with CNFs showed an average increase in stiffness of 15% and 20% for bending and tensile, respectively. The laminates, on the other hand, showed an increase in bending stiffness of 20% and 15% for tensile and modulus, respectively. In the case of ILSS and ILFT modes I and II, the addition of CNFs promoted average increases in the order of 50%, 100%, and 50%, respectively.

Effect of MWCNTs on static, dynamic, and wear performance of Vacuum Assisted Resin Infusion Molding (VARIM) processed glass fabric/epoxy polymer composites

In the present work, MWCNTs were used in wt.% of 0.075, 0.15, and 0.3 in epoxy resin, and then glass fabric/epoxy polymer (GF/EP) composites were fabricated using VARIM setup. The mechanical and wear properties of GF/EP composites were compared with and without the addition of MWCNTs. Maximum improvement in tensile and flexural performance were seen in GF/EP composites at 0.15 weight percent MWCNT addition when compared to a neat GF/EP one, based on static testing such as tensile and flexural tests. High-cycle fatigue test results show a relatively higher cycle count with 0.15 wt.% MWCNTs addition in the GF/EP composite compared to the GF/EP without the addition of MWCNTs. The wear performance also improved with a lower friction coefficient as well as a lower track depth and width for MWCNTs with added GF/EP than plain GF/EP composite. Therefore, in addition to decreasing surface softening and improving the wear performance of glass fabric epoxy composites, MWCNTs (0.15 weight percent) increased the interfacial adhesion at the fiber/matrix interface. This study establishes an optimum ratio of 0.15 wt.% of MWCNTs addition in glass fabric/epoxy polymer composites for enhancement in their mechanical and wear performance.

Study on the mechanical and thermal properties of aramid fibre reinforced with sawdust particulates in an epoxy matrix composite: a novel material for structural applications

AbstractThis study investigates the development and characterization of a novel composite material for structural applications, aiming to address the growing demand for lightweight, durable and versatile materials. The composite integrates aramid fibre reinforced with sawdust particulates within an epoxy matrix. Methodologically, the composite was fabricated using a hand layup process, ensuring even distribution and strong adhesion between components. Mechanical testing revealed significant enhancements in tensile strength (up to 135.29 MPa) and flexural strength (up to 136.92 MPa) with the inclusion of sawdust particulates, optimizing stress distribution and impact resistance. Hardness was also improved, peaking at a Rockwell hardness number of 94. Thermal analysis demonstrated moderate thermal conductivity (1.92 W mK−1) and a high heat deflection temperature (109 °C), indicating excellent thermal stability. SEM provided insights into the composite's microstructure, confirming uniform sawdust distribution and robust fibre–matrix adhesion. These findings underscore the potential of this composite for lightweight, durable and thermally stable structural applications. © 2024 Society of Chemical Industry.

Mechanical performance of epoxy matrix composites reinforced by physically and chemically treated hemp fiber

AbstractHemp fiber is one of the most common reinforcements for polymer matrix composites and it is widely used in various applications due to its environmentally friendliness, favorable physical and mechanical properties. In spite of the numerous merits of the hemp fiber reinforced polymer composites, improvement of poor interfacial properties between the hemp fiber and polymer matrix is limited. The main objective of this work is to investigate the effect of increased fiber surface area and alkaline surface treatment on the mechanical performance of hemp fiber reinforced epoxy composites. An elevated temperature aqueous debundling treatment was employed to generate a large number of individual fibers from fiber bundles and was associated with a threefold increase in specific fiber surface area. The fiber dimension and surface properties were investigated through optical microscopy, confocal microscopy, and scanning electron microscopy. The effects of different debundling treatment times and additional alkaline treatment on the mechanical properties were studied. It was found that composites reinforced by the debundled hemp fiber with further alkaline treatment exhibited the best tensile and flexural properties in comparison to other composites reinforced with debundled hemp fiber without further alkaline treatment or with untreated hemp fiber.Highlights Provided a new physical method for separating hemp fiber bundle into individual hemp fibers using boiling water and blending. Debundled fibers resulted in a 3.5 times increase in fiber surface area for better bonding with epoxy matrix. Debundling process combined with chemical (alkaline) treatment to further improve the compatibility between individual fiber and epoxy. The effects of the debundling only, alkaline treatment only, and combined debundling + alkaline treatment on composite properties were studied.

Mechanical and physical properties of epoxy/SiC composites simulated

This study aimed to predict the mechanical properties of SiC-reinforced epoxy. The cross-linked reinforced epoxy was simulated using Material Studio 7.0 (Accelrys, Inc.). Various percentages of SiC (0, 4, 6, 8, and 10) wt% were used in the simulations. A density curve and cell size diagram are obtained from MD simulations of SiC-epoxy nanocomposites. Under a 0.5 GPa pressure, Forcite dynamic simulations showed that amorphous cells have densities that are close to epoxy density (1.2 g cm−3). Simulations have shown that epoxy/SiC composites respond well to a variety of mechanical strains. Increasing the SiC weight percentage increases the stiffness matrix coefficient of epoxy composites, which is demonstrated by increased stiffness matrix coefficients. Computational studies of epoxy/SiC composites have suggested up to 10% SiC nanoparticles by weight will maintain the epoxy matrix’s density in industrial applications.