Plain Epoxy Research Articles

Experimental investigation of pseudo-ductility in plain weft-knitted epoxy composite laminates under tension

The inherent brittleness of unidirectional fiber-reinforced composites represents a major complication in their broad practical applications. However, exploiting different reinforcement architectures can offer an opportunity for highly desirable ductile fracture nature. This article is aimed at investigating experimentally the tensile behavior of an epoxy laminate reinforced by different layers of plain weft-knitted fabrics. The fabricated laminates were subjected to uniaxial tension in different loading directions, and the corresponding tensile responses were recorded. Basic mechanical properties were characterized and digital image correlation (DIC) was employed to capture surface deformations. Tensile test results demonstrated strong nonlinearity and pseudo-ductility as well as loading-direction dependence in this type of composite laminates. Fracture tests were conducted showing high fracture toughness ranging from 10 to 20 MPa·m1/2. Typical damage modes were characterized using microscopy, which were coupled to a few distinct tensile deformation stages. This work demonstrates that weft-knitted composites are promising in permitting great amounts of pseudo-ductility with clear warning before complete failure. It is also expected to contribute to the understanding of the specific role of weft knit fabrics in composite laminates.

Dual-scale reinforcement of co-cure single lap joints through graphene nanoparticles and CFRP Z-pin

This study presents the report of the dual scale strengthening process to the co-cure (CC) single lap joint (SLJ) reinforced by Graphene nanoparticles (GNP) and carbon fiber reinforced polymer (CFRP) Z-Pin. The shear test indicated that inner and outer reinforcing with GNP in adhesive and Z-pin in SLJ improved shear properties. The combined reinforcement of GNP and 90°/Z-pin enhances shear strength under static loading with 99.89% compared to plain epoxy CC SLJ. After testing, microscopic images of the fractured specimen surface were used to investigate failures. The fractography studies reveal that adding GNP to the adhesive and Z pin in SLJ roughens the surfaces, strengthening adhesive-adherend contact.

Advanced adhesive repairs and reinforcements for curved glass/epoxy composite laminates

This study investigates the repair of damaged curved glass/epoxy composite laminates through various adhesive reinforcements and adhesively bonded external patches. The experimental procedures involve fabricating laminates, conducting four-point bending tests, quasi-static indentation tests, and optimizing damaged areas. Results demonstrate the influence of repairs on curved beam strength and interlaminar tensile strength. Adhesive repairs with chopped fiber reinforcement outperform plain epoxy and particle fiber-reinforced repairs, preserving 51.28% of curved beam strength. Adhesively bonded external patches, both single and double, with chopped fiber reinforcement exhibit significant strength recovery 72.08% and 80.78% compared to virgin samples. The study emphasizes the effectiveness of adhesively bonded external patches, particularly those with chopped glass fiber reinforcement, in enhancing curved beam strength and interlaminar tensile strength. This research provides valuable insights for repairing angled structures, such as those in airplane components, showcasing potential applications of these techniques for structural maintenance.

Mechanical and Ballistic Properties of Epoxy Composites Reinforced with Babassu Fibers (Attalea speciosa).

The mechanical and ballistic performance of epoxy matrix composites reinforced with 10, 20, and 30 vol.% of babassu fibers was investigated for the first time. The tests included tension, impact, and ballistic testing with 0.22 caliber ammunition. The results showed an improvement in tensile strength, elastic modulus, and elongation with the addition of babassu fiber, and the 30 vol.% composite stood out. Scanning electron microscopy analysis revealed the fracture modes of the composites, highlighting brittle fractures in the epoxy matrix, as well as other mechanisms such as fiber breakage and delamination in the fiber composites. Izod impact tests also showed improvement with increasing babassu fiber content. In ballistic tests, there was an increase in absorbed energy. All composites surpassed plain epoxy by over 3.5 times in ballistic energy absorption, underscoring the potential of babassu fiber in engineering and defense applications.

Investigation of vibration, flexural, tribological and flame retardant properties on rubber crumb-reinforced polymer composites

This research aims to fabricate polymer matrix composites with improved mechanical, flame retardant, and damping properties by incorporating waste rubber crumbs as the reinforcement. The damping characteristics of the polymer matrix composites reinforced with different weight percentages of rubber crumb such as 0, 2.5%, 5%, and 7.5% were analyzed using a free vibration test. The experimental results confirmed that the addition of rubber crumb significantly improved the damping characteristics of the material. In addition, the rubber crumb-reinforced composites showed improved mechanical and fire-retardant properties. The flexural strength improved exceptionally with the increase in rubber reinforcements up to 7.5%, whereas the tensile strength increased up to 2.5% weight and reduced with the further increase in rubber. Enhanced flame-retardant properties were witnessed in the polymer composites reinforced with rubber crumb than that of the plain Epoxy - Glass fibre composites. Thermogravimetric analysis (TGA) were also used to ascertain the thermal properties. The scanning electron microscope was employed to analyze the surface and fractography of the polymeric composites. The overall results showed the contemporary effect of rubber crumbs on polymer composites.

Dynamic analysis of GPLs reinforced microcapsules subjected to moving micro/nanoparticles using mathematical modeling and deep-neural networks

In the realm of engineering, the use of cylindrical microcapsules containing moving micro/nanoparticles is crucial. Therefore, biomechanical engineers must focus on increasing its stability so that it may be used in a variety of scenarios. Thus far, graphene nanoplatelets, or GPLs, have shown their efficacy as an epoxy reinforcement in enhancing the material's characteristics in comparison to plain epoxy. This indicates that GPL-reinforced epoxy has the potential for use as the fiber composite's matrix phase. Thus, bending data of the thick cylindrical microcapsule with GPL reinforcement under a moving load is reported in this study. A modified couple stress theory or MCST with a single length scale parameter is proposed for simulating the micro-size structure. The high-order shear deformation theory are used to represent the displacement fields while taking the shear-strain function into account. The space-dependent equations are solved using the Laplace transform approach and the double Fourier series, respectively, using forced vibration analysis. The results are compared and validated with another published study in the literature after the modeling and solution of the governing equations of the GPLs reinforced microcapsules exposed to moving micro/nano particles. With the help of the findings from the mathematical modeling section, deep neural networks (DNN) with output, input, and hidden layers are used to mimic the existing microcapsule in order to provide further verification and introduce machine learning methodologies for addressing engineering challenges. A cylindrical microcapsule under motion under a micro/nanoparticle may be modeled in the area of biomechanical engineering using the current outputs obtained from mathematical modeling and DNN sections.

Thermal and Colorimetric Parameter Evaluation of Thermally Aged Materials: A Study of Diglycidyl Ether of Bisphenol A/Triethylenetetramine System and Fique Fabric-Reinforced Epoxy Composites.

The main modifications of thermal and colorimetric parameters after thermal aging of DGEBA/TETA system (plain epoxy) and fique-fiber woven fabric-reinforced epoxy composites are described. As a preliminary study, thermal analysis was carried out on epoxy matrix composites reinforced with 15, 30, 40 and 50% fique-fiber woven fabric. After this previous analysis, the 40% composite was chosen to be thermally aged, at 170 °C. Three exposure times were considered, namely, 0, 72, 120 and 240 h. Samples were studied by thermogravimetric analysis (TGA), differential thermal analysis (DTA), differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and colorimetry analysis. Significant color changes were observed after thermal aging combined with oxidation. It was also found that the thermal behavior of the plain epoxy showed greater resistance after thermal exposure. By contrast, the composites were more sensitive to temperature variations as a result of thermal stresses induced between fique fibers and the epoxy matrix.

Synthesis and characterization of polypyrrole‐fly‐ash‐adenosine composite reinforced epoxy coating for anticorrosive applications

AbstractPolypyrrole (PPy), PPy‐fly ash, and PPy‐fly ash‐adenosine composite in an epoxy resin system were studied for potential applications in the field of corrosion protection. The composite was prepared using a simple and cost‐effective in‐situ chemical oxidative method by interfacial polymerization technique. The synthesized composites were added into the epoxy coating matrix. All the studied formulations show excellent adhesion (5B) and good chemical resistance and passed flexibility test without any crack formation. Pencil hardness increases from 2H to 4H while scratch resistance increases from 1.5 to 2 kg for both PPy‐Ash 3wt% and PPy‐Ash‐adenosine 3 wt% as compared to plain epoxy. The contact angle observed to be 80.4° for plain epoxy and with PPy‐Ash‐adenosine 5 wt% it is 98.75°. Anticorrosive properties of the coatings were evaluated using electrochemical impedance spectroscopy bode plot analysis and salt spray tests. There was an increase in impedance from 2.5 to 4.25 ohm, as the addition of PPy‐Ash‐adenosine composite. The results indicated that the composite coatings exhibited significantly higher corrosion protection properties compared to the pure epoxy coating. The enhanced corrosion protection performance of the composite coatings was attributed to the synergistic effect of PPy, fly ash, and adenosine.

Ballistic Behavior of Epoxy Composites Reinforced with Amazon Titica Vine Fibers (Heteropsis flexuosa) in Multilayered Armor System and as Stand-Alone Target.

Seeking to improve personal armor equipment by providing mobility and resistance to penetration, this research aimed to explore the potential of sustainable materials in order to assess their ability in ballistic applications. Titica vine fibers (TVFs) extracted from aerial roots of Heteropsis flexuosa from the Amazon region were incorporated at 10, 20, 30, and 40 vol% into an epoxy matrix for applications in ballistic multilayered armor systems (MASs) and stand-alone tests for personal protection against high-velocity 7.62 mm ammunition. The back-face signature (BFS) depth measured for composites with 20 and 40 vol% TVFs used as an intermediate layer in MASs was 25.6 and 32.5 mm, respectively, and below the maximum limit of 44 mm set by the international standard. Fracture mechanisms found by scanning electron microscopy (SEM) attested the relevance of increasing the fiber content for applications in MASs. The results of stand-alone tests showed that the control (0 vol%) and samples with 20 vol% TVFs absorbed the highest impact energy (Eabs) (212-176 J), and consequently displayed limit velocity (VL) values (213-194 m/s), when compared with 40 vol% fiber composites. However, the macroscopic evaluation found that, referring to the control samples, the plain epoxy shattered completely. In addition, for 10 and 20 vol% TVFs, the composites were fragmented or exhibited delamination fractures, which compromised their physical integrity. On the other hand, composites with 30 and 40 vol% TVFs, whose Eabs and VL varied between 166-130 J and 189-167 m/s, respectively, showed the best physical stability. The SEM images indicated that for composites with 10 and 20 vol% TVFs, the fracture mode was predominantly brittle due to the greater participation of the epoxy resin and the discrete action of the fibers, while for composites with 30 and 40 vol% TVFs, there was activation of more complex mechanisms such as pullout, shearing, and fiber rupture. These results indicate that the TVF composite has great potential for use in bulletproof vests.

Thermal Behavior of Curaua-Aramid Hybrid Laminated Composites for Ballistic Helmet.

Hybrid composites are expanding applications in cutting-edge technology industries, which need materials capable of meeting combined properties in order to guarantee high performance and cost-effectiveness. This original article aimed for the first time to investigate the hybrid laminated composite thermal behavior, made of two types of fibers: synthetic Twaron® fabric and natural curaua non-woven mat, reinforcing epoxy matrix. The composite processing was based on the ballistic helmets methodology from the North American Personal Armor System for Ground Troops, currently used by the Brazilian Army, aiming at reduced costs, total weight, and environmental impact associated with the material without compromising ballistic performance. Thermal properties of plain epoxy, aramid fabric, and curaua mat were evaluated, as well as the other five configurations of hybrid laminated composites. These properties were compared using thermogravimetric analysis (TGA) with its derivative (DTG), differential thermal analysis (DTA), and thermomechanical analysis (TMA). The results showed that the plain epoxy begins thermal degradation at 208 °C while the curaua mat at 231 °C and the aramid fabric at 477 °C. The hybrid laminated composites curves showed two or three inflections in terms of mass loss. The only sample that underwent thermal expansion was the five-aramid and three-curaua layers composite. In the third analyzed temperature interval, related to the glass transition temperature of the composites, there was, in general, an increasing thermal stability behavior.

Effect of GO-modified epoxy on the bond behavior of old-new concrete and comparison with different surface preparation techniques

The interface of old to new concrete is the weakest plane during retrofitting and repairing of concrete structures, resulting in the interface or adhesive failure of the composite formed. Various surface preparation techniques and adhesives have been used and reported in the literature to improve the bond behavior of concrete-to-concrete interface. Epoxy is a commonly used adhesive to bond existing concrete with new overlay concrete, as it provides high adhesion and chemical resistance; however, inadequate roughness and low strength negatively affect the epoxied concrete joints, causing poor bonding at the concrete interface. On the other hand, the use of graphene oxide (GO) in epoxy showed significant enhancement in its mechanical properties. Hence, in the present study, GO-modified epoxy has been proposed as an adhesive to improve the bond performance of the interface between existing and new concrete by conducting split tensile, bi-surface shear, and slant shear tests. Simultaneously, a comparison has been carried out with other frequently used surface preparation techniques such as grinding wire brushing (GW), grooves, and adding carbon and glass fiber laminate over the existing concrete with and without neat (plain) epoxy. The GO-modified epoxy has been prepared using three different GO concentrations; out of them, 0.05% by weight turned out to be the optimum concentration and performed best under all bond strengths and resulted in concrete failure instead of adhesive failure. Furthermore, scanning electron microscopy (SEM) revealed homogeneous dispersion of GO at 0.05% by weight and formation of the bond between GO and cement hydrates with both concrete interfaces. As a result, GO-modified epoxy turned out to be a high-strength adhesive to join existing concrete with fresh overlay concrete for strengthening, retrofitting, and repairing concrete structures and shows an effective composite action.

Carbon nanotube‐based polymer nanocomposites: Evaluation of barrier, hydrophobic, and mechanical properties for aerospace applications

AbstractThe anticorrosive and mechanical properties of carbon nanotubes (CNTs) in epoxy resin (EP) coatings have been improved by the integration of molybdenum disulfide (MoS2) and 3‐aminopropyltrimethoxysilane (APTMS) for surface modification based on CNTs. SEM/EDX, TEM, TGA/XRD, XPS, and XRD techniques were used to characterize the composites for the various formulations, including APTMS/CNTs, CNTs/MoS2, and APTMS/CNTs‐MoS2. By including APTMS/CNTs‐MoS2 composite, the EP coating exhibits improved anticorrosive and mechanical performance, as demonstrated by electrochemical methods and mechanical testing. Superior hydrophobic property of EP‐APTMS/CNTs‐MoS2 is confirmed by its WCA of 167°. Additionally, it was discovered that the EP‐APTMS/CNTs‐MoS2 had a resistance that was significantly larger (17,421 kΩ.cm2) than the plain epoxy (102 kΩ.cm2), and its hardness (1695 MPa), adhesion (19.7 MPa), and tensile (237 MPa) properties all are improved significantly. Therefore, the newly developed EP‐APTMS/CNTs‐MoS2 could act as the vital material for coating AA7475 aluminum alloy used in aerospace applications.

CNC drilling and comparative investigation on machinability of novel epoxy composite

To investigate the rate of material removal (MRR) of CNC machined (drilling) epoxy based novel hybrid composite included with synthetic glass, natural banana fibers and carbon particles. The samples of both the groups under investigation were made by conventional hand-lay technique. Samples were prepared as per standards and machining (drilling) is performed using a vertical milling CNC machine. The rate of material removal of the samples was investigated and compared between the groups by doing 9 experiments per group and also repeated once, and accordingly 18 experiments per group. Independent t tests were performed using SPSS statistical software tool for investigating the rate of material removal. The observations made on results, Group-1 comprising plain epoxy (PE) displays an average of 4.38 mm3/sec, while Group-2 encompassing of carbon particles (Cp) (5 wt.%)/Banana fiber (BF) (5 wt.%)/glass fiber (GF) (15 wt. %)/epoxy (75 wt. %) showed an average of 5.54 mm3/sec. The statistical analysis of the T-test reveals that there is a significant (P0.05) variation of MRR amid Group-1 and Group-2. This finding is based on the fact that there is a change in the mean variance of MRR. It is clearly understood that the inclusion of BF and Cp along with GF have significant influence on the improvement in MRR.

The effect of fiber orientation and stacking sequence on carbon/Kevlar/epoxy intraply hybrid composites under dynamic loading conditions

AbstractThis work investigated the thermo‐mechanical behavior of (carbon/Kevlar) intraply hybrid composites. The carbon/Kevlar plies' orientation and sequential arrangement were varied. Carbon and Kevlar composites, as well as five different intraply hybrids (HFRPs) composite such as carbon‐0°/Kevlar‐90°, carbon‐45°/Kevlar‐135°, carbon‐90°/Kevlar‐0°, carbon/Kevlar (inter‐changing layer), and carbon/Kevlar‐45° (inter‐changing layer) composites, and a plain epoxy panel, have been developed. The thermo‐mechanical characteristics of the fabricated composites were estimated using a dynamic automated analyzer under changing mechanical and thermal load conditions. The DMA technique measured the HFRPs composite visco‐elastic parameters by increasing the temperature from 30°C to 150°C at frequencies ranging from 1 to 20 Hz. Flexural test characteristics for neat epoxy, carbon fiber‐reinforced composites, Kevlar fiber‐reinforced composites, and carbon/Kevlar fiber‐reinforced composites were estimated to aid the study. The experimentally measured versus analytically calculated viscoelastic parameters were related. The results revealed that carbon‐90° oriented in warp direction/Kevlar‐0° oriented in weft direction exhibited higher modulus and lower loss tangent followed by carbon/Kevlar plies oriented in alternate layers and carbon/Kevlar plies oriented in inter‐changing layers at 45°. Carbon‐0° introduced in the weft direction/ Kevlar‐90° introduced in the warp direction, and carbon‐45°/Kevlar‐135° exhibited intermediate storage and loss modulus and a moderate loss tangent at the various frequency levels considered in the study.

Thermal, mechanical and dielectric properties of glass fiber reinforced epoxy-lanthanum manganite nanocomposites

Abstract The mechanical, thermal and dielectric properties of lanthanum manganite (LaMnO3) epoxy nanocomposites reinforced with silane coated E-glass fiber are reported. Structural and morphological characteristics of the LaMnO3, synthesized by the solution combustion method, were studied via X-ray diffraction, EDAX and scanning electron microscopy. LaMnO3/epoxy composites containing various percentages of LaMnO3 (LME) were prepared via hand lay-up method and tested for tensile, flexural and impact strength. Improved properties were obtained with the addition of LME compared to plain epoxy composites. The thermal stability of the composites remains almost unaltered by the filler loading. Variation in the dielectric characteristics with filler loading is attributed to the percolation of charge carriers due to the interfacial zonal overlapping in the nanocomposite resulting in a change of the dielectric characteristics.

A study on the influence of silanized clay on the barrier, hydrophobic and mechanical properties of epoxy coated steel in natural seawater

ABSTRACT Diethoxy(3-glycidyloxypropyl) methylsilane (GPMS), a surface modification agent, is used to give halloysite nanoparticles a hydrophobic behaviour and improve their ability to disperse in epoxy polymers (EP). Surface roughness and hydrophobicity (WCA: 144°) are both quite high in EP-GPMS/Clay coatings. The corrosion behavior of coated steel surfaces was investigated using electrochemical methods. The EP-GPMS/clay nanocomposite coating was shown to have about 63 times higher coating resistance than the EP coating. The EP-GPMS/Clay displayed better coating resistance (6687.71 kΩ.cm2) and a lower corrosion current density (4.25 μA/cm2) than plain epoxy (1.01 kΩ.cm2; 287.21 μA/cm2) even after prolonged exposure to the electrolyte, according to electrochemical studies. Compared to the pure EP (0.0599 mm/year), the EP-GPMS/clay coated sample had the lowest corrosion rate (0.0017 mm/year). According to SECM data, at 15 d of immersion, the Fe dissipation at the surface of the EP-GPMS/Clay coating (2.6 nA) is much smaller than the plain EP (14.7 nA). Additionally, the EP-GPMS/Clay showed enhanced adhesive properties. The EP with silanized clay offers an outstanding oxygen and water repellent, hydrophobic, and barrier properties. Due to the environmental safety of clay/silane, this kind of coating might be employed as a workable coating substance for industrial applications.

Yttrium doped ZnO nanofillers reinforced epoxy coating for anticorrosion application

In the present study, synthesized pure and Yttrium (0.5, 1.0, 1.5, 2.0 and 2.5 mM) doped Zinc Oxide (YZO) nanoparticles by chemical precipitation method. X-ray diffractogram asserts the hexagonal wurtzite structure of ZnO nanoparticles. The average crystallite size was found to be 22–17 nm. The hexagonal shape, surface morphology, particle size and elemental composition of the samples were analyzed by FESEM, HRTEM and EDAX. The anticorrosive property of nanoscopic size (17 nm) YZO/epoxy nanocomposite was studied by electrochemical impedance spectroscopy (EIS) technique in both neutral and acidic media. Epoxy/YZO nanocomposites were prepared using different loadings (0.05, 0.10 and 0.15 wt%) of yttrium doped ZnO nanoparticles. The results obtained confirm that 0.10 wt% is the optimum concentration to get superior anticorrosion activity Epoxy/YZO nanocomposites were applied on mild steel substrates. The acquisition of yttrium doped ZnO nanofillers into the plain epoxy coating materially increased the charge transfer resistance Rct by 3.5 times in oxalic acid solution as against epoxy/ZnO coating. This encapsulates that the YZO nanoparticles are a potential anti-corrosive filler in coat on mild steel.

Dynamic Mechanical Analysis and Ballistic Performance of Kenaf Fiber-Reinforced Epoxy Composites.

Several industry sectors have sought to develop materials that combine lightness, strength and cost-effectiveness. Natural lignocellulosic natural fibers have demonstrated to be efficient in replacing synthetic fibers, owing to several advantages such as costs 50% lower than that of synthetic fibers and promising mechanical specific properties. Polymeric matrix composites that use kenaf fibers as reinforcement have shown strength increases of over 600%. This work aims to evaluate the performance of epoxy matrix composites reinforced with kenaf fibers, by means of dynamic-mechanical analysis (DMA) and ballistic test. Through DMA, it was possible to obtain the curves of storage modulus (E′), loss modulus (E″) and damping factor, Tan , of the composites. The variation of E′ displayed an increase from 1540 MPa for the plain epoxy to 6550 MPa for the 30 vol.% kenaf fiber composites, which evidences the increase in viscoelastic stiffness of the composite. The increase in kenaf fiber content induced greater internal friction, resulting in superior E″. The Tan was considerably reduced with increasing reinforcement fraction, indicating better interfacial adhesion between the fiber and the matrix. Ballistic tests against 0.22 caliber ammunition revealed similar performance in terms of both residual and limit velocities for plain epoxy and 30 vol.% kenaf fiber composites. These results confirm the use of kenaf fiber as a promising reinforcement of polymer composites for automotive parts and encourage its possible application as a ballistic armor component.

Enhancing bonding behavior between carbon fiber-reinforced polymer plates and concrete using carbon nanotube reinforced epoxy composites

Externally bonded carbon fiber reinforced polymer (CFRP) composites have been widely used as repairing or strengthening materials for deteriorated reinforced concrete (RC) structures. This study discusses whether carbon nanotube (CNT) can be used as an additive to enhance bonding strength between concrete and CFRP. In this study, two CNT types: single walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), were mixed with two different types of epoxies. CNTs were added at 0.25%, 0.5%, and 1.00% by weight of epoxy to obtain the optimal performance. Single-shear test were conducted to investigate bonding behavior including bond strength, ultimate slip, effective bond length, bond stress-slip relationship, interfacial fracture energy, and crack formation between CFRP plate and concrete. The results showed that epoxy modified by 0.5% SWCNTs and 1.0% MWCNTs by weight of epoxy enhance the ultimate load and slip, bond strength, and interfacial fracture energy when compared to plain epoxy. However, high density epoxy modified with SWCNTs/MWCNTs showed diminished bonding properties.

Incorporation of crosslinked polydicyclopentadiene nanoparticles into epoxy thermosets via ring opening metathesis polymerization-induced self-assembly

In this contribution, we reported the generation of crosslinked polydicyclopentadiene nanoparticles in epoxy thermosets via polymerization-driven self-assembly approach. First, poly(ε-caprolactone)s (PCLs) with single cis -2-butene moieties in the main chains were synthesized, which were then employed as the macromolecular chain transfer agents (Macro-CTAs) for the ring-opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD). The ROMPs were carried out with the precursors of epoxy ( i.e., trimethylolpropane triglycidyl ether + 4,4′-methylenebis(2-chloroaniline)) as the medium of dispersion. At a lower temperature ( e.g. , 60 °C), the ROMPs were undergone completion and then the systems were heated to elevated temperature to start the curing reaction. It was found that the nanostructures were created in the cured thermosets, in which the crosslinked PDCPD nanoparticles were well dispersed in the thermosetting matrix. The crosslinked PDCPD nanoparticles displayed spherical, cylindrical and lamellar morphologies, influenced by the contents of modifier ( viz. DCPD + Macro-CTA) and the molecular weights of Macro-CTAs. Both dynamic light scattering and transmission electron microscopy showed that the generation of nanostructures followed a typical polymerization-induced self-assembly mechanism. Compared to plain epoxy, the nanostructured thermosets significantly displayed improved fracture toughness. The fracture toughness was readily modulated by controlling the contents of DCPD and the molecular weights of Macro-CTAs. • ROMP-induced self-assembly was performed with epoxy precursors as dispersion medium. • Crosslinked polydicyclopentadiene nanoparticles were generated in epoxy thermosets. • The nanostructured epoxy thermosets displayed improved fracture toughness.