Fiber-matrix Interface Research Articles

Assessment of interface characteristics and durability aspects of manufactured sand (M-sand) in engineered cementitious composites

Concrete structures usually tend to crack and cause several distresses, thus resulting in regular maintenance activities. Engineered Cementitious Composites (ECC) in structural applications are becoming popular due to their cracking resistance and deformability. However, the conventional mix design of ECC with silica sand levied a negative influence on cost and drying shrinkage, thereby affecting their practical implementation. In this study, the matrix properties and interface characteristics of ECC tailored with Manufactured sand (M-sand) replacing the river sand at varying proportions were investigated. The study conducted mechanical characterization, matrix fracture toughness, and single-crack tension tests to evaluate the micro-mechanical properties and fiber-matrix interaction. Furthermore, the shrinkage characteristics and permeability properties of ECC mixtures were also evaluated at various replacement levels of M-sand. The natural river sand adhered to the finer gradation, characterized by a fineness modulus of 1.63, while the M-sand exhibits a coarser gradation, having a fineness modulus 2.74. The experimental results showed that the ECC mixtures with M-sand improved the compressive strength (up to 29 %) at 100 % replacement level and marginally influenced the tensile strength. However, the tensile ductility and fiber bridging characteristics showed a noticeable decrease as the percentage replacement increased in the mixtures. On the other hand, the drying shrinkage of all M-sand ECC mixtures showed a notable reduction irrespective of the curing ages. It is also seen that the permeability properties were slightly increased compared to that of the control mixture. In summary, the study observed a trade-off between mechanical strength and tensile ductility, highlighting the effects of fiber-matrix interface tailoring on the overall performance of ECC mixtures with M-sand for various structural applications.

Micromechanics stiffness upscaling of plant fiber-reinforced composites

Fiber-reinforced green composites made from natural plant fibers are an increasingly popular sustainable alternative to conventional high-performance composite materials. Given the variety of natural fibers themselves, and the even larger variety of possible composites with specific fiber dosage, fiber orientation distribution, fiber length distribution, and fiber–matrix bond characteristics, micromechanics-based modeling is essential for characterizing the macroscopic response of these composites. Herein, an analytical multiscale micromechanics model for elastic homogenization is developed, capable of capturing the variety. The model features (i) a nanoscopic representation of the natural fibers to predict the fiber stiffness from the universal stiffness of the fiber constituents, mainly cellulose, (ii) a spring-interface model to quantify the compliance of the fiber–matrix bond, and (iii) the ability to model any (and any combination of) orientation distribution and aspect ratio distribution. Validation is performed by comparing the predicted stiffness to experimental results for as many as 73 composites available in the literature. Extensive sensitivity analyses quantify the composite stiffening upon increasing fiber volume fraction, fiber alignment, fiber length, and fiber–matrix interface stiffness, respectively.

Investigation of Fiber-Matrix Interface Strength via Single-Fiber Pull-Out Test in 3D-Printed Thermoset Composites: A Simplified Methodology.

The emergence of additive manufacturing technologies for fiber-reinforced thermoset composites has greatly bolstered their utilization, particularly within the aerospace industry. However, the ability to precisely measure the interface strength between the fiber and thermoset matrix in additively manufactured composites has been constrained by the cumbersome nature of single-fiber pull-out experiments and the need for costly instrumentation. This study aims to introduce a novel methodology for conducting single-fiber pull-out tests aimed at quantifying interface shear strength in additively manufactured thermoset composites. Our findings substantiate the viability of this approach, showcasing successful fiber embedding within composite test specimens and precise characterization of fiber pull-out strength using a conventional mechanical testing system. The test outcome revealed an average interfacial strength value of 2.4 MPa between carbon fiber and the thermoset epoxy matrix, aligning with similar studies in the existing literature. The outcome of this study offers an affordable and versatile test methodology to revolutionize composite material fabrication for superior mechanical performance.

Fabrication of bamboo-inspired continuous carbon fiber-reinforced SiC composites via dual-material thermally assisted extrusion-based 3D printing

Ceramic matrix composites (CMCs) structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerospace field. To address various functional requirements, this study integrates a biomimetic strategy inspired by gradient bamboo vascular bundles with a novel dual-material 3D printing approach. Three distinct bamboo-inspired structural configurations Cf/SiC composites are designed and manufactured, and the effects of these different structural configurations on the CVI process are analyzed. Nanoindentation method is utilized to characterize the relationship between interface bonding strength and mechanical properties. The results reveal that the maximum flexural strength and fracture toughness reach 108.6 ± 5.2 MPa and 16.45±1.52 MPa m1/2, respectively, attributed to the enhanced crack propagation resistance and path caused by the weak fiber-matrix interface. Furthermore, the bio-inspired configuration enhances the dielectric loss and conductivity loss, exhibiting a minimum reflection loss of −24.3 dB with the effective absorption band of 3.89 GHz. This work introduces an innovative biomimetic strategy and 3D printing method for continuous fiber-reinforced ceramic composites, expanding the application of 3D printing technology in the field of CMCs.

Silane treatment for sisal fibers to improve the degradation resistance and interface with cement matrix

In order to improve the degradation resistance of sisal fibers in the alkaline cement matrix and enhance the fiber-matrix interface adhesion, silane treatment on fiber was studied. Four kinds of commonly used silane coupling agents were selected to modify the sisal fibers via the simple dip-coating method. Contact angle, water retention, and semi-immersion tests were performed on the sisal fibers to determine the influence of silane treatment on their hydrophilicity and barrier property. The interfacial bonding between the sisal fibers and cement matrix was studied by a self-designed fiber pull-out test. Furthermore, the degradation of sisal fibers embedded in cement matrix and sisal fiber reinforced cementitious composites (SFRCC) was evaluated based on the changes of mechanical properties with accelerated aging. The results indicate that silane treatment is an efficient approach to mitigate the degradation of SFRCC.

Improving mechanical and thermal expansion properties of aluminum matrix composites reinforced by silicon carbide fiber

Combining the colloidal dispersion method with the squeeze melt infiltration technique, aluminum matrix composites with different volume fractions of silicon carbide fiber were fabricated at 680 °C under vacuum. Microstructure analysis found that composite presented a dense structure and fibers were homogeneously distributed in matrix. The hardness, yield strength and elastic modulus of the composite monotonically increased with increasing the volume fraction of fiber. The highest flexural strength for composite with 10 vol% SiC fiber was achieved. The improved mechanical properties could be attributed to the dispersion strengthening and enhanced load transferring ability by fibers as well as the dislocation strengthening. On the other hand, the coefficient of thermal expansion of composites was measured at temperature up to 400 °C. It was found that the uniform introduction of silicon carbide fiber could significantly low the CTE of aluminum matrix composite, which could be attributed to the low CTE of SiC fiber and good fiber–matrix interface bonding.

Lignocellulosic-Based/High Density Polyethylene Composites: A Comprehensive Study on Fiber Characteristics and Performance Evaluation

Lignocellulosic-based polymer composites have gained significant interest due to their ‘’green’’ character as a response to environmental concerns. A diverse array of lignocellulosic fibers is utilized, depending on fiber dimensions, chemical composition, moisture content, and the fiber–matrix interface. The aim of this study is to establish an alternative standardized methodology, aimed at comparatively estimating the performance of polymer composites through the examination of individual plant fibers. The fibers studied are ramie, hemp, flax, and kenaf, and HDPE-based corresponding composites were analyzed for their performance across various fiber-content levels (10, 20, and 30 wt.%). It was found that kenaf showcases the largest average fiber diameter, succeeded by hemp, ramie, and flax. Additionally, ramie and kenaf exhibit elevated levels of crystallinity, suggesting increased cellulose content, with kenaf having the lowest crystallinity index among the fibers compared. Based on Thermogravimetric analysis, ramie displays the lowest moisture content among the examined fibers, followed by hemp, flax, and ultimately kenaf, which is recorded to have the highest moisture content, while, similarly, ramie exhibits the lowest mass loss at the processing temperature of the corresponding composites. Composites containing fibers with smaller diameters and higher crystallinity indexes and lower moisture absorptions, such as ramie and hemp, demonstrate superior thermal stability and exhibit increased Young’s modulus values in their respective composites. However, poor interfacial adhesion affects mechanical performance across all composites. Understanding fiber morphology, inner structure, and thermal stability is important for developing new composite materials and optimizing their selection for various applications.

Measurement of tensile and shear strength of interfacial bonding in fiber reinforced soft composites combining experiments and simulation

Interfacial bonding strength plays a key role in the mechanical performance of fiber reinforced polymers. However, measurement of interfacial bonding strength in fiber reinforced soft composites (FRSCs) becomes a challenging issue, because the large deformation capability of soft matrix invalidates most of current testing methods. This paper demonstrates an advanced method combining experiments and simulation, which provides a convenient and reliable means to measure both tensile strength and shear strength of interfacial bonding for FRSCs. The specimen is made by embedding a fiber bundle in a soft plate for transverse tensile test. Various stress states along the fiber–matrix interface can be realized by controlling the inclination angle of fiber bundle to the stretching direction. Tensile strength and shear strength of interfacial bonding in FRSCs can be estimated based on the analysis of critical stress states. The comparison with the widely adopted fiber pull-out test indicates that the nominal shear strength obtained in pull-out test is severely underestimated.

Production and characterization of sustainable biocompatible PLA/walnut shell composite materials

Various treatments, such as alkaline and silane treatments, are commonly applied to natural fillers before production to enhance their quality, thermal stability, and water absorption capacity and improve the fiber–matrix interface properties. However, these processes are not environmentally friendly and may escalate the production cost of composites due to the need for additional processing steps in mass production. This study delves into the impact of untreated walnut shell (WS) filler material, employed in varying ratios (ranging from 10 to 40%) as a filler, on the mechanical, thermal, morphological, and physical properties of environmentally friendly polylactic acid (PLA) matrix composites. The experimental results highlight a significant decrease in tensile modulus by 28%, tensile strength ranging from 32 to 65%, a decrease in flexural modulus by 22%, and flexural strength ranging from 24 to 58% with varying WS filler ratios. Time-dependent water absorption and increased density were observed. FT-IR analysis indicates structural similarities, while DSC results show minimal effects on glass transition temperature and crystallinity. TGA results reveal reduced thermal stability with increasing WS content. SEM microstructure imaging demonstrates homogeneous WS particle distribution, but higher WS content leads to increased brittleness and diminished resistance properties. In conclusion, this study underscores the importance of balancing sustainability through WS filler ratios while preserving mechanical performance.

Fatigue and post-fatigue behavior of FRCM-concrete specimens under direct shear and bending conditions

The combined effect of cyclic loading and steel rebar corrosion can determine the premature deterioration of reinforced concrete (RC) structures subjected to dynamic and environmental actions. The use of fabric-reinforced cementitious matrix composites (FRCM) is a promising solution to extend the fatigue life of RC structures. Externally bonded FRCMs are applied to the tension side of structural members to reduce the rebar stress level, thus delaying fatigue crack nucleation and/or propagation. A key aspect for the design of FRCM strengthening of these structures is the matrix-fiber bond behavior under fatigue loading. In this paper, a critical review of currently available studies on the fatigue behavior of FRCM-strengthened RC beams is presented. Then, the results of 25 bond tests on PBO FRCM-concrete specimens are provided and discussed. These tests include both single-lap direct shear and modified beam tests performed in quasi-static and cyclic mode. The results obtained show that the cyclic load may induce progressive debonding at the matrix-fiber interface with rupture of fiber filaments. Modified beam tests are more affected by these phenomena than direct shear tests. The rupture of fiber filaments is confirmed by the results of post-fatigue tests that show capacities lower than those of corresponding quasi-static tests.

Enhancement of the contact behavior of a quasi-isotropic carbon fiber/epoxy matrix laminate with an elastic body by modifying the fiber-matrix interphase using graphene nanoplatelets

This study analyzed the effect of incorporating graphene nanoplatelets in the fiber-matrix interphase on the behavior of a multiscale composite laminate based on carbon fibers and epoxy resin subjected to contact loads. The selected loading mode was the contact between an elastic surface and a cylinder. The multiscale composite material used was a quasi-isotropic laminate with graphene nanoplatelets (GnPs) added at the fiber-matrix interface. The specimens were prepared with 0.0%, 0.1%, and 0.25% by-weight GnPs. Laminate beams were used according to the ASTM D7264 standard, and contact was studied in two configurations, applying the load at the edge of the laminate and in the other, in the plane of the test pieces. The normal strains in the contact region were determined experimentally using the interferometric Moiré technique. These results were compared with estimations using the Hertz contact theory and the finite element method (FEM). The normal strains in the contact area of specimens with fibers modified with 0.1% GnPs were lower than those with 0.25% or fibers without surface modification. Excellent agreement between the experimental results along lines in the contact zone with those estimated with the FEM. The normal strains in a direction perpendicular to the applied load obtained by the Hertz theory for the maximum deformation were slightly higher than those obtained by FEM. Except for those calculated for the normal strain in εy for the load in the direction of the thickness, although the distribution was very similar to those obtained by FEM as well as the experimental one.

Strengthening Mechanism and Damping Properties of SiCf/Al-Mg Composites Prepared by Combining Colloidal Dispersion with a Squeeze Melt Infiltration Process.

SiC-fiber-reinforced Al-Mg matrix composites with different mass fractions of Mg were fabricated by combining colloidal dispersion with a squeeze melt infiltration process. The microstructure, mechanical and damping properties, and the corresponding mechanisms were investigated. Microstructure analyses found that SiCf/Al-Mg composites presented a homogeneous distribution of SiC fibers, and the relative density was higher than 97% when the mass fraction of Mg was less than 20%; the fiber-matrix interface bonded well, and no obvious reaction occurred at the interface. The SiCf/Al-10Mg composite exhibited the best flexural strength (372 MPa) and elastic modulus (161.7 GPa). The fracture strain of the composites decreased with an increase in the mass fraction of Mg. This could be attributed to the strengthened interfacial bonding due to the introduction of Mg. The damping capacity at RT increased dramatically with an increase in the strain when the strain amplitude was higher than 0.001%, which was better than the alloys with similar composition, demonstrating a positive effect of the SiC fiber on improving the damping capacity of composite; the damping capacity at a temperature beyond 200 °C indicated a monotonic increase tendency with the testing temperature. This could be attributed to the second phase, which formed more strong pinning points and increased the dislocation energy needed to break away from the strong pinning points.

Performance analysis of fiber-reinforced polypropylene composite laminates under quasi-static and super-sonic shock loading conditions for impact application

In the present research, glass and basalt fiber-reinforced polypropylene composites’ behaviour in quasi-static and dynamic conditions is studied. Composites were fabricated by vacuum assisted Compression molding method. Composites failure under quasi-static tension and compressive conditions was studied along with its failure behaviour under low-velocity impact and super-sonic shock loading under dynamic conditions. The study results showed that basalt fiber-reinforced polypropylene (Basalt/PP) composite’s tensile and compressive strength is higher than glass fiber-reinforced polypropylene (Glass/PP). The Basalt/PP showed no penetration against low velocity impact (LVI) with negligible deformations till 50 J. However, the Glass/PP perforated at 50 J with various failure patterns occurring at back side. The fiber-matrix interface adhesion plays an important role in super-sonic shock loading by absorbing shock wave energy due to ductile nature of polypropylene and the two composites absorbed energy via matrix and fibers failure, no brittle failure of laminates occurred under shock loading.

Damage evolution of CFRP laminates by normal and oblique impact erosion of pulsating water jets

Impact direction is one of the critical factors affecting the waterdrop erosion behavior of materials. In this paper, rain erosion damage behavior of a typical carbon fiber reinforced polymer (CFRP) laminate is investigated as a function of the impingement angle (0° as normal impact and 15°, 30°, 45° as oblique impact deviated from the normal) and the relative fiber orientation (parallel PA and perpendicular PE to the fiber direction of the surface layer) under the waterjet velocity of 320 m/s and the impact frequency of 50 Hz via a pulsating waterjet erosion test rig. After continuous impact of multiple waterjets, the typical damage of CFRP laminates is mainly composed of the central erosion crater and the upheaval of the surrounding surface layer. The onset and evolution of damage are mainly driven by the shear action of lateral jetting and stress concentration of hydraulic penetration exerted at the surface irregularities. There is no significant difference in the damage modes between the normal and oblique impacts, except for the asymmetric distributions of matrix cracking in PA-orientation and delamination in PE-orientation caused by the angle inclination. With the impingement angle increasing, the volume loss and erosion depth decrease while the incubation period increases mainly due to the decreases of water hammer pressure and contact area. The PA-orientation can cause lower incubation period and larger erosion mass loss than PE-orientation before the surface ply is penetrated, with the underlying mechanism related to the distinct tensile properties of CFRP laminates along longitudinal and transversal directions and the asymmetric properties of fiber–matrix interface. According to the fitting results of erosion curves, it is possible to describe the incubation period and the erosion rate of CFRP laminates under oblique impact using a two-branch equation, and Springer model can give reasonable prediction for the average incubation period and PA-orientation erosion rate of a certain oblique impact occasion with known 0° impact erosion results.

Enhancing carbon fiber reinforced aluminum laminates with cellulose paper interlayers: experimental characterization of tensile, flexural, and interlaminar fracture toughness

ABSTRACT The mechanical properties of fiber metal laminates (FML) are influenced by several various factors. Interface adhesion plays a particularly crucial role in interlaminar strength. Enhancing the interlaminar strength of carbon fiber reinforced aluminum laminate (CARALL) composites present a persistent challenge due to inherent weaknesses between metal and composite elements. Therefore, this study focuses on improving the interlaminar performance of CARALL composites by introducing cellulose paper interlayer at the metal/composite interface. The cellulose paper interlayer offers the advantage of being cost-effective and sustainable. Cellulose paper-interleaved CARALL composites were fabricated by vacuum bagging method and exhibited noteworthy improvements in mechanical properties. Comparative analysis with pristine samples revealed substantial enhancements, including a 15% increase in tensile strength, a remarkable 42% improvement in flexural strength, and a significant enhancement in mode-I fracture toughness by 65%. Furthermore, the cellulose paper interleaving played a crucial role in stabilizing fracture formation at the fiber-matrix interface, with mode II fracture toughness witnessing a 3% increase. Visual examination revealed the underlying toughening processes occurring in the interfacial area. This innovative approach of interleaving laminated composites with cellulose paper emerges as a sustainable and effective strategy, demonstrating the potential to fortify and toughen the interlaminar zones of CARALL composites.

An experimental review on enhancing the low and high-velocity impact resistance of NFCs through nanoparticle reinforcement

Nanoparticles are widely used in biocomposite materials due to their ability to improve the mechanical properties of composites. This comprehensive review analyzes the use of nanoparticles to enhance the experimental low and high-velocity impact resistance of natural fiber composites. Various nanoparticles like carbon nanofibers, carbon nanotubes, boron nitride, zinc oxide, and titanium dioxide were investigated as reinforcements at different loading levels. The addition of nano-ZrO2 alone or with graphene oxide yielded the highest impact resistance and interlaminar shear strength of basalt fiber/epoxy composites. Cloisite 20A clay improved the mechanical properties of an epoxy matrix. Carbon/epoxy laminates showed improved maximum impact force, energy absorption, and displacement with 2wt% carbon nanofibers loading. Nanoparticles were found to enhance moisture and temperature resistance by strengthening the fiber–matrix interface. The literature demonstrated that small amounts of well-dispersed nanoparticles can meaningfully improve natural fiber composites’ impact resistance, strength, stiffness, toughness, and energy absorption through mechanisms like crack arresting and bridging. Hybrid carbon-basalt fibers and calcium carbonate nanoparticles also enhanced composite performance. Balancing the nanoparticle loading is crucial to prevent agglomeration effects. Future studies on their toxicity and environmental impacts would be needed for widespread commercial applications of Biocomposites.

Autogenous healing of the interface between hollow natural fiber (HNF) and reactive magnesia cement (RMC) matrix

The fiber-matrix interface healing determines the restoration of tensile strength of fiber reinforced cementitious composites (FRCCs). This work first-timely investigates the autogenous healing of debonded interface between hollow natural fiber (HNF) and reactive magnesia cement (RMC) matrix and subsequent tensile strength recovery. HNF-RMC single-fiber specimens are preloaded to induce interfacial debonding, and then conditioned under water-air cycles for healing. The healing-induced recovery of the interfacial properties in the HNF-RMC group are significantly higher than the control PVA-RMC and PVA-PC groups. Tensile test of notched FRCCs demonstrated that the tensile strength of HNF-RMC can be more than doubled after cracking-healing, and its healing efficiency is around 50% higher than that of PVA-PC and PVA-RMC. Based on microstructural characterization in situ and finite element modeling, the increased healing degree is attributed to two new mechanisms related to the special porous microstructure of HNF. First, the lumens and micropores within cell of HNF can be the pathway for CO2 and water penetration, which promotes the formation of healing products (e.g., hydrated magnesium carbonates) within fiber-matrix interface and hence the recovery of chemical and frictional bonds. Second, the healing products formed within lumens caused lateral fiber expansion, and thus prominently enhanced the frictional bond.

Incorporation of Graphene Nanoplatelets into Fiber-Reinforced Polymer Composites in the Presence of Highly Branched Waterborne Polyurethanes.

Enhancing interfacial interactions in fiber-reinforced polymer composites (FRPCs) is crucial for improving their mechanical properties. This can be achieved through the incorporation of nanomaterials or chemically functional agents into FRPCs. This study reports the tailoring of the fiber-matrix interface in FRPCs using non-functionalized graphene nanoplatelets (GNPs) in combination with a waterborne, highly branched, multi-functional polyurethane dispersion (HBPUD). A unique ultrasonic spray deposition technique was utilized to deposit aqueous mixtures of GNP/HBPUDs onto the surfaces of carbon fiber fabrics, which were used to prepare epoxy-prepreg sheets and corresponding FRPC laminates. The influence of the polyurethane (PU) and GNP content and their ratio at the fiber-matrix interface on the tensile properties of resulting high-performance composites was systematically investigated using stress-strain analysis of the produced FRPC plates and SEM analysis of their fractured surfaces. A synergistic stiffening and toughening effect was observed when as low as 20 to 30 mg of GNPs was deposited per square meter of each side of the carbon fiber fabrics in the presence of the multi-functional PU layer. This resulted in a significant improvement in the tensile strength from 908 to 1022 MPa, while maintaining or slightly improving the initial Young's modulus from approximately 63 to 66 MPa.

The effect of imperfect bonding on stress distribution in fibrous composites

An attempt was made to map the distribution of stress in fibrous composites with imperfect bonding. Two analytical micro-mechanics models were developed. In the first model, the composite was subjected to axial tensile loading, parallel to the fiber direction, and the assumption of iso-strain was employed to derive the control equations. In the second model, the composite was loaded in the direction transverse to the fiber. An iso-stress condition was employed, and Airy stress function was utilized to articulate the stress and displacement equations. An assumption of how the stress is transferred between the matrix and the fiber was introduced in both models. To investigate and validate the models, specimens were fabricated using a carbon plain weave fabric and a geopolymer matrix. Single fiber pullout and three-point bending tests were carried out. The maximum average tensile stress obtained from the three-point bending tests, as well as the mechanical properties of the fiber and geopolymer, served as input for the models. Results indicate that the effect of the level of bonding is very high in the transverse direction while almost negligible in the axial direction. The difference in the maximum value of the axial tensile stress at the fiber-matrix interface was used to calculate the numerical value of the interfacial shear strength, and the numerical result matched the data obtained from the single fiber pullout test.

Improvement of tensile strength and toughness in aramid/epoxy composites by sequential air plasma and (3-glycidyloxypropyl) trimethoxysilane treatments

This work explores sequential surface treatments involving atmospheric-air plasma and (3-glycidyloxypropyl) trimethoxysilane (GLYMO) to enhance the tensile properties of aramid/epoxy composites. To prove the technical advantages of this approach, aramid fibers received individual (atmospheric-air plasma or GLYMO) or sequential (plasma followed by GLYMO, and vice versa) surface treatments. Single fiber tensile tests (SFT) and X-ray photoelectron spectroscopy (XPS) were employed to characterize changes in aramid fibers upon the surface modifications. SFT revealed that none of the surface treatments compromised their tensile strength (σ max ). Applying GLYMO, whether individually or in sequence (GLYMO followed by plasma and plasma followed by GLYMO), led to a significant enhancement in the fibers’ elastic modulus (E). Composites with plasma-treated fibers displayed a 5% increase in E and an 8.5% increase in σ max , with no changes in toughness. However, the most notable improvements were achieved through sequential plasma followed by GLYMO treatments, resulting in a ~ 10% increase in σ max and a remarkable ~ 40% improvement in toughness. Plasma introduces oxygen-containing groups to the fiber surface, facilitating GLYMO grafting. Subsequent crosslinking of GLYMO with the epoxy resin strengthens the fiber-matrix interface. This sequential surface modification offers an alternative pathway for fabricating composites with superior toughness and σ max .