Standard Epoxy Research Articles

Glass fibre hybridization to improve the durability of circular flax fibre reinforced composites with off-the-shelf recyclable polymer matrix systems for large scale structural applications

Natural fibre composites (NFCs) are not durable in the long run because of the susceptibility of natural fibres to environmental conditions and specifically moisture. Hybridizing NFC laminates externally, with synthetic fibre reinforcements, may improve durability, due to their inherent environmental resistance. This work aims to investigate the effects of glass hybridization, on flax fibre composites, studied via accelerated ageing. In specific, the durability of hybrid flax/glass fibre reinforced polymer composites, with two recyclable polymer matrices was investigated. Unidirectional (UD) flax and UD glass fibre reinforcements were employed to fabricate laminates, with two fully-recyclable off-the-shelf resin systems, as matrix: (i) a bio-based epoxy resin and (ii) an acrylic liquid thermoplastic (Elium®). In addition, a standard petroleum-based epoxy polymer matrix was for reference purposes. Weathering and hygrothermal ageing were used to test the durability of coupons, exposed to UV radiation/condensation/water spray environment (weathering ageing), and full-immersion in distilled water at 23, 40, and 60°C (hygrothermal ageing). In all cases, ageing was performed for a total duration of 56 days. The performance of the unaged and aged composite coupons was assessed and compared in terms of flexural and viscoelastic performance as well as SEM (Scanning Electron Microscopy) analysis. It was revealed that the addition of glass fibres with flax fibres in the hybrid composites improves the performance and better resistance against ageing environments than their neat flax fibre composites.

Advancing corrosion protection in confined spaces: a solvent-free UV LED-curable coating for steel pipelines with enhanced barrier properties and harsh environment performance

This study investigates a novel solvent-free, UV LED-curable coating as a robust corrosion protection solution for the inner surface of steel pipelines. The properties of the UV-cured film were characterized in terms of reactivity, thermomechanical properties, and adhesion to metal substrates. The coating was applied to the inside steel pipelines and cured using a patented UV LED lamp designed to fit in confined spaces. Finally, electrochemical impedance spectroscopy characterization and an accelerated cyclic electrochemical technique were performed on the coated pipes to study the corrosion protection properties of the coating, both with and without the addition of inorganic fillers. The results were compared to a commercially available thermally cured coating. It was found that the UV-cured coating confers high barrier properties, effectively preventing liquid penetration even under elevated temperature conditions. Furthermore, the corrosion protection performance in harsh environments was comparable to and, in some cases, higher than standard epoxy linings.

Mechanical Behaviour of As-Manufactured and Repaired Aligned Discontinuous Basalt Fibre-Reinforced Vitrimer Composites.

The aim of this research is to investigate basalt as a natural mineral-based fibre together with a vitrimeric resin as a sustainable alternative to standard composite materials. Vitrimers combine the properties of thermoset and thermoplastic polymers, enabling the repair of specimens and hence prolonging the lifetime of the composite material. The micro-mechanical characteristics between the basalt fibres and the vitrimer resin are reported and shown to match those of a standard Skyflex K51 epoxy resin. Discontinuous (4 mm) basalt fibres were employed to produce aligned discontinuous fibre-reinforced composites (ADFRCs) using the high-performance discontinuous fibre (HiPerDiF) technology. The mechanical characteristics of the laminates were investigated through tensile testing and the fracture zones were analysed under a scanning electron microscope. By normalising the results by their respective fibre volume fraction, it was discovered that the vitrimer-basalt ADFRCs exhibited, on average, a 4% higher strength and a 25% higher stiffness compared to their basalt epoxy counterparts. The repair potential of the vitrimer ADFRC specimens was explored during low-temperature compression repair. Two approaches were tested using double-sided local- and full-patch repair. Both successfully recovered a significant amount of their prime strength. In conclusion, the potential of the sustainable vitrimer-basalt composite is shown by its competitive mechanical performance. Combining this with the manufacturing flexibility, repair potential, and recyclability of the material, the vitrimer-basalt composite seems to be a competitive alternative to standard glass epoxies.

Enhancement of hydrophobic, resistive barrier and anticorrosion performance of epoxy coating with addition of Clay-Modified Green Silico-Graphitic Carbon

Under this study, a straightforward method for producing clay-modified silico-graphitic carbon (CGSGC) was developed and applied to create CGSGC/epoxy coatings for carbon steel (CS). The CGSGC was synthesized using a mixture of 25 % pond clay, and 75 % remnant agricultural biomass by mass via pyrolysis route. The aim was to evaluate the barrier and anti-corrosion properties of these coatings. The results demonstrated that adding 0.1 wt.% of CGSGC in the epoxy (EP) matrix enhanced its anti-corrosion inhibition capabilities by 99.8 % when compared with standard EP coating. The 0.1 wt.% CGSGC/EP mixed coating also exhibited robust hydrophobicity with WCA of 142.2° and thermal stability up to 250 °C with 2–3 % coating weight reduction. The microhardness of the optimized sample shows a 59.18 % improvement compared to standard EP coating. SEM images revealed improved EP compactness and reduction in microstructural defects (holes and cracks), with the incorporation of 0.1 wt.% CGSGC. 3D profilometry showed a smoother surface for the 0.1 wt.% CGSGC/EP coating. Similar such materials, while being abundantrly and renewably available, can be a safer alternative to conventional hazardous chemicals for protecting carbon steel from corrosion; not to mention the carbon credit benefits they entail.

Experimental Analysis of the Effect of Limescale on the Wettability of Indirect Evaporative Cooling System Plates

Indirect evaporative cooling systems have attracted much interest in recent years as they guarantee good cooling effectiveness, with lower energy demand with respect to traditional systems, thus helping to address the issue of climate change. Many studies have shown that an increase in the wettability of recuperator plates results in an improvement in the system performance. However, if the water injected into the system comes from the city water supply, it will contain calcium carbonate residuals, which will form limescale layers on the plates, thus possibly changing their wetting behavior. Therefore, the wettability of three surfaces (an aluminum uncoated surface, AL, a standard epoxy coating, STD, and a hydrophilic lacquer, HPHI) was analyzed in the presence of limescale formations, and compared with that obtained in a previous study for corresponding clean surfaces. The results showed that the HPHI contact angle was reduced in the presence of limescale (median: 50°), that for STD was slightly increased (median: 81°), and that for AL was again reduced (median: 75°). Consequently, HPHI was confirmed to be the most wettable surface in both clean and limescale conditions. Finally, an analysis was undertaken evaluating the spreading factor and the reversible work of adhesion, which were in good agreement with the qualitative visual observations of the plates covered with limescale.

A Preliminary Study of Thermosets from Epoxy Resins Made Using Low-Toxicity Furan-Based Diols.

Glycidyl ethers are prepared from a series of furan-based diols and cured with a diamine to form thermosets. The furan diols demonstrate lower toxicity than bisphenol-A in a prior study. The diglycidyl ethers show improved thermal stability compared to the parent diols. Cured thermosets are prepared at elevated temperature using isophorone diamine (IPDA). Glass transition temperatures are in the range of 30-54 °C and depend on the structure of the furan diol. Coatings are prepared on steel substrates and show very high hardness, good adhesion, and a range of flexibility. Properties compare favorably with a control based on a bisphenol-A epoxy resin. The study demonstrates that epoxy resins based on furan diols, which have been shown to have lower toxicity than bisphenol-A, can form thermosets having properties comparable to a standard epoxy resin system; and thus, are viable as replacements for bisphenol-A epoxy resins.

Nucleophilic amino acids as a renewable alternative to petrochemically-derived amines in glycerol epoxy resins

The standard epoxy resin curing agents revealed are from unsustainable petroleum-based sources, which produce poisonous exhaust when cured. Amino acids, a bio-based epoxy curing agent with amino and carboxyl groups, are another potential curing agent. Water-soluble epoxy resins cured with lysine (Lys), glutamic acid (Glu), leucine (Leu), and serine (Ser) as amino acids were investigated. The results showed that the water-soluble epoxy resin (glycerol epoxy resins, GER) was cured with Lys and Glu after reacting. Fourier transform infrared (FT-IR) spectroscopic analysis of the GER-Lys showed that the amino and carboxyl groups of Lys primarily reacted with the epoxy groups of GER. The elongation at break of Lys-cured GER (GER-Lys) cured at 70 ℃ with a molar ratio of 1꞉0.75 was 75.32%. The fact that elongations at break of GER-Lys (79.43%) were higher than those of GER-Glu (17.33%), respectively supports the decrease of crosslinking density by the amino acid-cured GER reaction. The potential of Lys and Glu alternatives for petrochemical amines is demonstrated and provides promising opportunities for industrial application.

Investigation of the ductile deformation potential of microscale epoxy materials

In fiber reinforced polymers (FRP), the matrix, e.g. an epoxy system, usually has a microscopic size and therefore may have other properties than the standard bulk samples. It is known that a size effect exists, for epoxy also in terms of ductility or plasticity. However, to date, there is no physical, mechanochemical or molecular explanation for the correlation of plasticity and gauge volume, especially for an archetypical brittle standard epoxy matrix. The specific limits of the gauge volume for these ductile effects are unknown as well. Therefore, a new manufacturing method to produce thin epoxy films with thicknesses between 15 and 100μm is developed. These films are investigated by differential scanning calorimetry (DSC) with regard to the degree of cross-linking. The mechanical properties are determined by tensile and creep test, also at different temperatures. In the next step, a suitable analysis method for the correlation of molecular structure and mechanical deformation behavior is developed. Manufactured films are investigated by ex situ and in situ infrared spectroscopy (IR) to analyze the molecular mechanisms caused by load introduction. Various pre-processing and interpretation methods for the determination of spectral changes, such as peak shifts, are used to figure out the specific molecular changes related to the mechanical stress from the raw spectral data. It was possible to detect molecular changes of the highly cross-linked macromolecules as a result of plastic deformation caused by tensile load. Shear bands and necking are visualized by photoelastic analysis and a better understanding of the brittle material’s ability to form shear bands is achieved.

Composite material with enhanced recyclability as encapsulant for photovoltaic modules

Encapsulation of photovoltaic cells was carried out using a transparent glass fiber reinforced composite with enhanced chemical recyclability based on a matrix of an epoxy resin containing cleavable functional groups. The current-voltage curves showed a decrease of 6.3% on the short-circuit current (Isc) after encapsulation of the cell, lower than the one observed for the reference non-recyclable standard epoxy composite. Its performance stability under thermal cycling, ultraviolet (UV), and damp-heat exposure was evaluated and compared with the one of the reference standard epoxy. Both resins showed good stability performance under UV exposure and thermal cycling accelerated aging. Moreover, a power loss below the 5% allowed by the photovoltaic standard was observed for the recyclable resin after 1000 h of damp-heat exposure, even the pronounced loss of 4.7% in power remains a concern. Regarding the recyclability, the composite was dissolved in acetic acid dissolution and glass fiber fabrics were successfully recovered. A new module was manufactured with these fabrics, showing this time a loss of 12% in Isc comparing with the non-encapsulated cell. Further work will consider improving the moisture barrier properties of the composite, and adjusting the recycling conditions to allow component recovery valid for new modules.

Effect of accelerated weathering on the performance of natural fibre reinforced recyclable polymer composites and comparison with conventional composites

This work investigated the long-term performance of unidirectional (UD) flax fibre reinforced recyclable polymer composites (FFRPs), after accelerated weathering for a total of 56 days, in laboratory environment. The employed recyclable polymer matrices were a bio-based epoxy and a liquid thermoplastic acrylic resin. The performance of the developed composites, were compared with traditional UD glass fibre composites (GFRPs), employing a standard petro-based epoxy resin, in terms of flexural and viscoelastic properties, while visual inspection and Scanning Electron Microscopy (SEM) were employed to investigate further the effects of ageing after exposure. It was revealed that the reinforcing fibres dominated the performance of the composites after ageing, whilst the choice of polymer matrix exhibited less influence.

A New Look at Silicon Carbide

Silicon Carbide, SiC is one of the most widely used materials that plays a critical role in industries such as: aerospace, electronics, industrial furnaces and wear-resistant mechanical parts among others. Although SiC is widely used in electronics and other high technology applications, the metallurgical, abrasive, and refractory industries are dominate by volume. It is only in the last five or six years that SiC has gained a new and important role in the semiconductor industry. SiC has become a key material in the drive towards electrification. It’s unique physical properties, wide band gap, especially, high temperature performance and “ease of manufacturability makes it a key material going forward. The physical properties that make SiC so unique also represent some serious problems to large scale manufacturing of SiC diodes, transistors and modules. SiC is a very tough material, it has a Mohs hardness rating of 9.5 approaching that of diamond. Just as the semiconductor industry needed high quality defect free silicon wafers to move forward, so did the SiC industry. High quality defect free wafers have just come into the market. They are 4 and six wafers that will allow SiC. These boules can be “sliced” in wafers and run on a standard CMOS fabrication process. Next comes the dicing of the wafers into devices. A diamond saw has to be run at a very slow rate to a material almost as hard as the diamond itself. Die attach brings an interesting problem the devices are generally rate at 200+ deg C and voltages >1000W. Standard epoxy and even Au/Si eutectic die attach has issues has issues at these extreme operating conditions. Lastly, the epoxy molding compound has to be capable of withstanding the harsh conditions and not breakdown. These are all challenges that are being met today. This is a continuing story of how the semiconductor industry adapts to ever changing requirements

The analysis of the bond strength between natural fiber reinforced polymer (NFRP) sheets and concrete

This study was conducted to develop an empirical model for predicting the bond strength between Natural Fiber Reinforced Polymer (NFRP) sheets and concrete. This was achieved through the production of 22 concrete block specimens with a size of 100 mm × 100 mm × 300 mm, having a single longitudinal reinforcing bar with a diameter of 10 mm in the center of its cross-section and a pre-existing crack in the middle of its length on 2 opposite sides. NFRP composites with a size of 50 mm × 240 mm were subsequently applied to both sides containing a crack. It is important to note that the NFRP was produced from fabric using 4 different types of fibers including jute, silk, pineapple, as well as dense and non-dense abaca fibers. Moreover, three different types of bonding adhesives were applied to bond the NFRP composite produced from abaca fiber to the concrete surface, and these include the standard epoxy resin, polyester resin, and thixotropic epoxy resin. Meanwhile, those produced using other types of fibers only required the standard epoxy resin. The NFRP was also made with different numbers of fabric layers ranging from 1 to 3, thereby, resulting in different thicknesses for the sheets. A tensile load was later applied through both ends of the reinforcing bar to rupture the NFRP sheets. It is pertinent to state that the bond strength model was proposed as a function of NFRP sheet thickness with due consideration for the influence of fiber density, fiber type, and bonding adhesive type. It was discovered that the bond strength calculated using the proposed model was very similar to the value obtained from the experiment. This study also determined the load-strain relationship and strain distribution along NFRP sheets. Moreover, the use of 2 and 3 layers of fabrics enhanced the bond strength by 118–350% and 312–400% respectively depending on the fiber and bonding adhesive types.

Experimental Characterization of the Wettability of Coated and Uncoated Plates for Indirect Evaporative Cooling Systems

Indirect Evaporative Cooling (IEC) is a very promising technology to substitute and/or integrate traditional air conditioning systems, due to its ability to provide cooling capacity with limited power consumption. Literature studies proved that a higher wettability of the IEC plates corresponds to better performance of the system. In this work, wettability of three different surfaces used for IEC systems plates—uncoated aluminum alloy (AL), standard epoxy coating (STD), and a hydrophilic lacquer (HPHI)—is studied and characterized in terms of static and dynamic contact angles. The static contact angle resulted to be the lowest for the HPHI surface (average 69°), intermediate for the STD surface (average 75°), and the highest for the AL surface (average 89°). The analysis of the dynamic contact angles showed that their transient behavior is similar for all the surfaces, and the advancing and receding contact angles obtained are consistent with the results of the static analysis. These results will be useful as input parameters in models aimed at predicting the IEC system performance, also using computational fluid dynamics.

Infusible Thermoplastic Composites for Wind Turbine Blade Manufacturing: Fatigue Life of Thermoplastic Laminates under Ambient and Low‐Temperature Conditions

Traditionally, thermoset resins such as polyesters (PE) and epoxies are used as the polymer matrix for construction of wind turbine blades. However, concern about their end‐of‐life treatment garners interest to use thermoplastics for increased recyclability. However, the high viscosity of molten thermoplastics inhibits their use in manufacturing wind turbine blades with injection or compression molding. A recently developed, infusible, reactive thermoplastic resin overcomes this technological barrier. Toward verifying that this recyclable resin is suitable for use in wind turbine blades, a dataset of R = 0.1 and R = 10 fatigue data for glass fiber–reinforced acrylic composites is provided and equal fatigue life to industry standard epoxy and unsaturated PE resin systems is demonstrated. Specifically, R = 0.1 fatigue data for acrylic composites at room temperature and −30 °C for verification of low‐temperature performance are tabulated. To elucidate failure mechanisms, in situ mechanical testing with X‐ray computed tomography demonstrates that damage accumulation occurs by crack propagation along the fiber–matrix interface under cyclic loading. Infrared (IR) thermography predicts failure points in composites specimens with porosity defects introduced from nonideal manufacturing processes. Furthermore, these manufacturing defects are shown to compromise the fatigue life of the acrylic laminates by an order of magnitude.

Effect of using fibre reinforced epoxy adhesive on the strength of the adhesively bonded Single Lap Joints

In this paper, the static strength and elongation of the adhesively bonded Single Lap Joints (SLJs) at failure are enhanced by using glass fibres reinforced with epoxy adhesive. Commercially available Araldite, a standard epoxy adhesive, is utilised as the binding agent, while Aluminium plate and Glass Fibre Reinforced Plastic (GFRP) are used as metal and composite adherend materials, respectively, in the experiment. The performance of glass fibre reinforced epoxy adhesives in terms of strength improvement has been tested for two types of SLJs: MTM (Metal-to-Metal) and MTC (Metal-to-Composite). The strength controlling parameters considered during the experiment are certain variables such as the alignment of the bundle of long glass fibres along the loading direction, the size of glass fibres and the weight ratio of short glass fibres reinforced with epoxy adhesive in the overlap region of the SLJ. The effects of these controlling parameters on the strength and elongation have been discussed. In addition, the bundles of long glass fibres are overlaid at the fillet region along the loading axis, extending beyond the overlap ends to observe the effect of the peel stress at the overlap ends and examine its effect on the failure strength of the SLJ. The experimental results show that there is a substantial increase in failure load and elongation. Fractography analysis has also been carried out to analyse the fracture surfaces using a Scanning Electron Microscope (SEM).

Cleavable epoxy networks using azomethine-bearing amine hardeners

This work is a proof-of-concept of the use of azomethine-bearing diamines as novel hardeners of standard epoxy compounds to yield cleavable and thermoformable covalent adaptable networks (CANs), with functional properties otherwise comparable to conventional epoxy networks. A suitable aromatic diamine (TPA-o-PD) was synthesised at acceptable purity for the intended use and successfully reacted with DGEBA. The resulting azomethine-bearing cured epoxy networks exhibited glass transition temperature values and a thermal stability profile similar to conventional epoxy network counterparts. In contrast to their conventional counterparts however, the azomethine-bearing networks were shown to dissolve in mixtures of chloroform and methanesulfonic acid, due to acid hydrolysis of at least some of the azomethine bonds of the network. The resulting recyclate material after evaporating the solvent was consistent with the profile of a thermoplastic polymer of high molecular weight, suggesting limited depolymerisation/network cleavage during dissolution in the chloroform/methanesulfonic acid mixture. The recyclates were soluble in polar aprotic solvents and showed good thermal stability, high Tg and molecular weight values, consistent with the attributes of engineering thermoplastics. Lastly, the cured networks were shown to be thermoformable at 200 °C, yielding self-standing films with only minor reduction of properties.

Interlaminar fracture toughness behaviour of carbon fibre reinforced polymer with epoxy-dicarboxylic acid vitrimer matrix

Healable and recyclable fibre reinforced vitrimer composites have been developed by taking advantage of the mechanical strength and topological rearrangement via bond exchange reaction. While the tensile properties of vitrimer laminates have been extensively studied, interlaminar properties have yet to be demonstrated. Experiments on mode I interlaminar fracture toughness and flexural characteristics of carbon fibre reinforced polymer (CFRP) composites based on epoxy-dicarboxylic acid vitrimer with various epoxy:acid ratios are presented in this paper. By hand lay-up and hot press, two vitrimer laminates with epoxy:acid ratio of 1:0.5 (off-stoichiometric, C50/CF) and 1:1 (stoichiometric, C100/CF) were successfully fabricated. From the flexural test, both C50/CF and C100/CF reveal marvellous stiffness of ∼60 GPa. Additionally, C50/CF also shows excellent flexural strength of 821 MPa which is in a similar range to conventional anhydride epoxy CFRP composites. In terms of interlaminar fracture properties under mode I loading, vitrimer CFRP composites outperform standard epoxy laminates on mode I fracture energy at initiation and propagation zones. At the initiation stage, fracture energies of C50/CF and C100/CF are two times higher than those of epoxy/CF. Furthermore, the average fracture energies during crack propagation of C50/CF and C100/CF were increased by ∼42% and ∼63%, respectively, when compared to epoxy/CF. The fracture surfaces of vitrimer laminates revealed matrix residue on the fibres, demonstrating that vitrimer and carbon fibres had good interfacial adhesion. These findings revealed a huge potential for further development of vitrimer CFRP composites for advanced applications.

Experimental and Numerical Comparison of Impact Behavior between Thermoplastic and Thermoset Composite for Wind Turbine Blades.

Damage generated due to low velocity impact in composite plates was evaluated focusing on the design and structural integrity of wind turbine blades. Impact properties of composite plates manufactured with thermoplastic and thermoset resins for different energy levels were measured and compared. Specimens were fabricated using VARTM (vacuum assisted resin transfer molding), using both matrix systems in conjunction with carbon, glass and carbon/glass hybrid fibers in the NCF (non-crimp fabric) architecture. Resin systems used were ELIUM 188O (thermoplastic) from Arkema Co., Ltd. and a standard epoxy reference, EPR-L20 from Hexion Co., Ltd. (thermoset). Auxiliary numerical finite element analyses were performed to better understand the tests physics. These models were then compared with the experimental results to verify their predictive capacity, given the intrinsic limitations due to their simplicity. Based in the presented results, it is possible to observe that ELIUM is capable to replace a conventional thermoset matrix. The thermoplastic panels presented similar results compared to its thermoset counterparts, with even a trend of less impact damage. Additionally, for both thermoplastic and thermoset resin systems, glass layups showed the lowest levels of damage while carbon panels presented the highest damage levels. Hybrid laminates can be applied as a compromise solution.

Self-healing epoxy coatings with microencapsulated ionic PDMS oligomers for corrosion protection based on supramolecular acid-base interactions

To obtain a self-healing coating and improve the corrosion resistance of coated low-carbon steel surfaces, a commercial epoxy coating was modified by adding microcapsules composed of a poly(methyl methacrylate) shell and a core of ionic polydimethylsiloxane (PDMS) oligomers. The encapsulation of amino- and carboxylic acid-terminated PDMS was achieved by a solvent evaporation process after the emulsification of core and shell materials, dissolved in CH2Cl2, in a suitable colloidal solution. A high core loading of nearly 50% wt. was successfully obtained by carefully increasing the interfacial tension of oil-in-water emulsion before the solvent evaporation. The microcapsule morphology was evaluated by SEM and optical microscopy analyses, which showed a particle diameter range of 20–70 μm. The presence of ionic PDMS oligomers as core materials was demonstrated by FTIR spectroscopy and thermogravimetric analysis (TGA), which was also employed to determine the core loading. The newly prepared microcapsules were then incorporated into the matrix of a commercial two-component epoxy coating. Corrosion protection abilities were assessed by comparing samples coated with a standard epoxy coating modified with a 20% wt. of microcapsules and the pristine epoxy coating. The corrosion protection performance of the modified coating was evaluated through electrochemical impedance spectroscopy (EIS) tests and potential vs time measurements, which showed that the microcapsules in the coating matrix caused a beneficial increase in barrier properties of a scratched coating. The surface damage triggered the release of functional PDMS oligomers, leading to the formation of a supramolecular ionic network and providing self-healing abilities to the modified coating.

Mixed-Mode Interlaminar Fracture Toughness of Glass and Carbon Fibre Powder Epoxy Composites-For Design of Wind and Tidal Turbine Blades.

Powder epoxy composites have several advantages for the processing of large composite structures, including low exotherm, viscosity and material cost, as well as the ability to carry out separate melting and curing operations. This work studies the mode I and mixed-mode toughness, as well as the in-plane mechanical properties of unidirectional stitched glass and carbon fibre reinforced powder epoxy composites. The interlaminar fracture toughness is studied in pure mode I by performing Double Cantilever Beam tests and at 25% mode II, 50% mode II and 75% mode II by performing Mixed Mode Bending testing according to the ASTM D5528-13 test standard. The tensile and compressive properties are comparable to that of standard epoxy composites but both the mode I and mixed-mode toughness are shown to be significantly higher than that of other epoxy composites, even when comparing to toughened epoxies. The mixed-mode critical strain energy release rate as a function of the delamination mode ratio is also provided. This paper highlights the potential for powder epoxy composites in the manufacturing of structures where there is a risk of delamination.