Search

Although numerous investigations study the improvement of flame retardancy of epoxy resins using additives, maintaining the flame retardant (FRs) modes of action present in the resins upon transfer to composites is challenging. In this study, ammonium polyphosphate (APP) and inorganic silicate (InSi) are loaded at 10%, 30%, and 50% by weight, in a diglycidyl ether of bisphenol A (DGEBA) resin cured with dicyandiamide and transferred to bidirectional (BD) glass fiber (GF) composites. Although a 50% loading of the FRs impacts the curing kinetics of the resin system, the effect on the glass transition temperature of the resin system remains negligible compared to reactive FRs in the state of the art integrated into the resin's chemical structure. Increasing the FR content improved the heat release characteristics in both the resins and composites. However, the charring mode of action is completely suppressed in the formulation with 10% APP + InSi. A 30% concentration of the FRs restored the charring action in the composite and the GFs provide increased protective layer action upon transfer to the composites. This study highlights the importance of accounting for the changing dynamics related to processing and flame retardancy upon transferring FRs from resins to composites. [ABSTRACT FROM AUTHOR]

Highlights In this work, silicone polymer (PSOL)/glass fiber (GF)/epoxy (EP) composites were prepared by employing PSOL as interfacial modifier into GF/EP composites. The mechanical and dynamic mechanical properties of the composites were investigated to determine the optimal PSOL content. The effect of PSOL on the wettability of EP on GF was investigated. The micromorphology of the GF/EP composites was also examined by scanning electron microscope. The results demonstrate that the interfacial bonding between GF and epoxy resin was improved significantly by the addition of PSOL. Specifically, the interlaminar shear strength, tensile strength, elongation at break, and blending strength of the PSOL/GF/EP composites increased by 9.28%, 13.61%, 12.66%, and 19.22%, respectively. Moreover, the original thermal stability of the composites was improved by the incorporation of PSOL. This study highlights the effectiveness of PSOL as an interfacial modifier, enhancing the overall performance of GF/EP composites while improving their thermal stability. Silicone polymer (PSOL)/glass fiber (GF)/epoxy (EP) composite material is made of glass fiber and epoxy resin by hand paste molding. Silicon polymers as interface modifiers can improve the interface between glass fiber and epoxy resin. PSOL/GF/EP composites have good mechanical properties. The glass transition temperature of GF/EP composites was increased by silicon polymer. [ABSTRACT FROM AUTHOR]

Highlights S2‐glass fiber reinforced plastics (S2‐GFRP) and basalt fiber reinforced plastics (BFRP) have emerged as crucial materials due to their exceptional mechanical properties, and milling of composite materials plays an important role in achieving desired properties. However, they have proven challenges due to relative inhomogeneity compared with metals, resulting unpredictability in quality of milling operations. The objective of this work is to investigate the effect of cutting parameters, tool geometry and tool surface materials on the surface quality of composites using burrs as a metric. S2‐GFRP and BFRP composites were produced by the vacuum infusion method. Helical and straight flute end mills were manufactured from high‐speed steel (HSS) and carbide rounds, and half of them were coated with titanium nitride using reactive magnetron sputtering technique. Taguchi L18 orthogonal array is used to determine the effect of tool material, tool angle, coating, cutting direction, spindle speed, and feed rate on the machining quality of S2‐GFRPs and BFRPs with respect to burr formations. Milling experiments were conducted under dry conditions and then the burrs were imaged to calculate the total area and length. Statistical analysis was also performed to optimize the machining parameters and tool type for ensuring the structural integrity and performance of the final composite parts. The results showed that the selection of tool material has the most significant impact on the burr area and length of the machined surface. The novel image analysis allows to analyze the extent of the burr size with a desirable operation speed for industrial applications. Aerospace grade S2‐Glass (S2‐GFRP) and basalt fiber reinforced plastics (BFRP) were manufactured. Carbide and HSS end mills were fabricated and coated with titanium nitride protective layer. FRPs were machined at various process parameters designed by Taguchi method. Distinctive image processing was firstly used to compute milling induced Burr area and length. Statistical analysis was performed to quantify the contribution of parameters and optimize milling. [ABSTRACT FROM AUTHOR]

This research investigates the influence of kevlar and glass fiber reinforcements on the mechanical and thermal properties of epoxy/vinyl ester (hybrid resin) composite. The hybrid resin was synthesized by achieving an interpenetrating network between epoxy and vinyl ester. The composites were characterized using tensile, flexural, impact, and thermo‐gravimetric analysis (TGA). Scanning electron microscopy was employed to analyze surface morphology whereas Fourier‐Transformation Infrared Spectroscopy (FT‐IR) was used to investigate the possible interaction between the constituents of the composites. The findings have shown a notable improvement in the mechanical properties after the hybridization of the resin. For reference, the tensile strength of glass/hybrid resin and kevlar/hybrid resin composites were observed to increase by 8.33% and 23.65%, as compared to glass/epoxy and kevlar epoxy composites respectively, whereas, the bending strength of these composites was improved by 8.36% and 30.61%, respectively. TGA also showed an enhanced thermal stability of the hybrid resin‐based composites. Such improvements are noticed due to multi‐resin incorporation (the oxirane group of epoxy reacts with the hydroxyl group of vinyl ester), confirmed by the FTIR, TGA, and morphological analysis. This study signifies that the proposed hybrid composites are better in terms of strength and modulus relative to conventional metallic materials. Highlights: The paper presents the development of novel hybrid resin, reinforced with synthetic fibers.Hybrid resin is imparted positively and is highly favorable in improving the mechanical properties of composites.The tensile strength of novel composites is increased by 8.33% and 23.65% relative to their base specimens, and a similar trend is observed in flexural and impact analysis.Fractured analysis showed that composite laminates deteriorated more intensely due to cohesive matrix fracture; adhesion failure was not observed at all, as evidenced by the emergence of micro‐cracks in resin.Developed novel composites exhibited maximum thermal stability; residual char in glass/epoxy/vinyl‐ester composite attained 17.81% higher, whereas kevlar/epoxy/vinyl‐ester achieved 3.56% relative to glass/epoxy and kevlar/epoxy base samples. [ABSTRACT FROM AUTHOR]

This study focused on the wear behavior of unidirectional, thick GF epoxy composites produced using the autoclave method. The thermal aging process was applied for 250 and 500 cycles to understand the wear behavior of the material as it ages over time. To evaluate the wear behavior of the samples, wear tests were carried out under three different loads (10, 20, and 30 N) and three different sliding distances (150, 300, and 450 m). Taguchi‐based regression analysis was used to analyze the experimental results. The results obtained were evaluated using ANOVA tables and main and contour graphs. When the test results are examined, it is surprisingly observed that the wear resistance of the composite material increases positively with the aging effect. With thermally aging while the coefficient of friction value of composite samples increases from approximately 0.12 to 0.3, the wear volume decreases from approximately 4 to 1.3 mm3. Taguchi based regression analysis showed that the relationship between wear and thermal cycle sliding distance and load can be established by reducing the number of experiments in wear studies. Highlights: Thermal aging effect on wear properties of thick GFRP was determined.Minimum wear volume and COF values were determined by applying ANOVA.It was determined that a load increment has the most impact on wear volume.Worn surface images supported the reduction in the wear rates of the thick GFRP.Empirical regression models developed for the mathematical prediction. [ABSTRACT FROM AUTHOR]

In recent years, the growing environmental awareness has prompted increased attention towards the substitution of nonrecyclable thermosetting epoxy resin composite materials with recyclable thermoplastic composite materials. The objective of this study is to utilize a laboratory‐made polymethyl methacrylate (PMMA)/methyl methacrylate (MMA) binary liquid resin (PMBLR) to prepare thermoplastic resin/glass fiber (GF) composite materials using the vacuum‐assisted perfusion method. These composites are then compared with GF‐reinforced thermosetting epoxy resin composites. The investigation reveals a significant influence of benzoyl peroxide (BPO) content on the mechanical properties of pure MMA and PMBLR casting resins, which also incorporate N‐methyl‐N‐((1‐methyl‐1H‐indol‐3‐yl) methyl) aniline (DMA) as redox composite initiators. The optimal mechanical properties for both types of casting resins are achieved at a DMA:BPO:MMA ratio of 0.5:1.2:100. Additionally, at a PMMA concentration of 24 wt% in PMBLR under this specific initiator ratio, the composites demonstrate the most desirable properties. Furthermore, a comparative analysis of PMBLR/GF composites and epoxy/GF composites indicates that the former exhibit superior 90° tensile strength, bending strength, and short beam shear strength. The fracture morphology analysis highlights discernible micro‐ductile fracture characteristics in PMBLR/GF composites, distinguishing them from epoxy/GF composites. Dynamic thermomechanical analysis (DMA) results further reveal a higher storage modulus and loss factor in PMBLR/GF composites when compared to epoxy/GF composites. Highlights: Glass fiber‐reinforced composites were fabricated at ambient temperature.A degradable PMMA/MMA binary thermoplastic resin (PMBLR) was developed as a replacement for non‐degradable epoxy.PMBLR composites exhibit enhanced strength compared to epoxy: tensile (+18.8%), bending (+27.4%), and short beam shear (+34.3%). [ABSTRACT FROM AUTHOR]

The main objective of the research is developed toward adsorption electronic devices (Interface material) with the performance examined by the physical, mechanical, and thermal properties of the E‐glass fiber reinforced with the epoxy composite and particulate dispersed into the matrix in partial fulfillment of tiny amount of aluminum powder particles and MWCNT. Composite membranes with 15 wt.% E‐glass fiber and 2 wt.%, 4 wt.%, and 6 wt.% fine aluminum powder particle concentrations were partially filled with 0 wt.%, 0.5 wt.%, and 1.0 wt.% MWCNTs. Vacuum lay‐up technique is used to create the better adhesive hybrid composite, which is then assessed of the characteristics of the materials. The maximum thermal conductivity of EAEM2 (E‐Epoxy, A‐Aluminum particle, E‐E‐glass fiber, M‐MWCNT) is 0.3057 W/mK. The tensile, bending, and impact strengths of EAEM1 composites are higher than those of EAEM2 and EAEM3 (average values of EAEM1 composites: 86 MPa, 123.33 MPa, and 90.66 J/m2). However, the Shore‐D hardness of EAEM3 is 95.33. The test findings demonstrate a significant improvement in thermal properties with minimal marginal decrements in mechanical capabilities when carbon allotropes are increased. The composite system's morphology (EAEM3) demonstrates a clustered distribution of aluminum powder particles in the matrix. [ABSTRACT FROM AUTHOR]

This study explores the application of abrasive waterjet drilling (AWJD) for varied patterns of GF/Al mesh hybrid composites (neat glass NG, AG: Al in the exterior surface, and GA: Al in the center). Key parameters such as jet pressure (P), standoff distance (S), and traverse speed (V) are systematically varied, influencing material removal rate (MRR), hole taper ratio (Tr), and roundness error (Re). Employing a Taguchi approach with an L9 design. It was indicated that the optimal conditions for maximum MRR are (P: 150 MPa, S: 2 mm, and V: 900 mm/min). V and S are the main influential parameters on Tr and Re. Gray relational analysis (GRA) is employed for simultaneous optimization, enhancing drilling performance. The optimal parameters P of 150 MPa, S of 2 mm, and V of 300 mm/min are determined. Validation trials confirm the effectiveness of the determined parameters. A robust multiple regression equation is formulated, providing a predictive model that aligns closely with experimental observations. Highlights: The hybrid composites were drilled via a nontraditional process.The attributes of the hole geometry and the material removal impacts were studied.Operation parameters were optimized to improve MRR, Re, and Tr.A multiple regression model and a confirmation test were performed and validated. [ABSTRACT FROM AUTHOR]

Three‐dimensional woven spacer composites (3DWSCs) with lightweight and excellent mechanical properties have promising application in communication, transportation, aerospace and other fields. However, traditional single‐layer 3DWSCs exhibit insufficient strength, especially when dealing with high thickness, as the pile yarns tend to buckle. In this study, inspired by the structural features of the Thalia dealbata, 3D woven integrated double‐layer glass fiber/epoxy resin spacer composites by mimicking were fabricated. Innovative integrated double‐layer structure design effectively improves the performance and failure mode of 3DWSCs under bending loads. Compared to single‐layer 3DWSCs, the resulting double‐layer 3DWSCs exhibited a 41.79% increase in peak bending load, a 46.85% increase in bending stiffness, and a 99.38% increase in energy absorption. In addition, the double‐layer 3DWSCs showed a low density of 0.52–0.55 g/cm3. This work introduces bioinspired double‐layer 3DWSCs with characteristics of lightweight and superior bending performance, potentially offering novel ideas for the design of high‐performance composites. Highlights: Inspired by the structural features of the Thalia dealbata, a 3D integrated woven double‐layer glass fiber/epoxy resin spacer composites by mimicking were fabricated.3D woven double‐layer spacer composites are lightweight (0.52–0.55 g/cm3) and can effectively improve the bending properties of single‐layer structures.Based on the analysis of the fracture morphology, the significant improvement of the fracture pattern of the single‐layer structure by the double‐layer structure is effectively demonstrated.This study introduces novel design strategies for multi‐layer lightweight composite materials and holds broad applications. [ABSTRACT FROM AUTHOR]

Frontal polymerization (FP) is a self-sustaining reaction that relies on polymerization exothermicity and heat transfer. This study explores the inplane and in-depth FP mechanisms of continuous fiber-reinforced epoxy composites. First, the effects of initiator and diluent concentrations on the FP behaviors of neat epoxy resins were examined. It was found that the frontal velocity and frontal temperature of the neat resins increase with an increase of either the initiator concentration or the diluent content, depending on the polymerization enthalpy and curing kinetics. Then, the FP behaviors of continuous carbon fiber and glass fiber-reinforced epoxy woven composites were investigated. The results showed that the in-plane FP behavior of the composites was primarily controlled by the thermal conductivity and specific heat capacity of the continuous fibers, whereas the in-depth FP behavior mainly depended on the pores of the woven fabrics. Highlights • Frontal velocity and temperature of neat resins are controlled by the polymerization enthalpy and curing kinetics. • The in-plane FP behavior of continuous fiber reinforced composites is dependent on the thermal conductivity and specific heat capacity of the fibers. • The in-depth FP behavior of composite is determined by both the thermal conductivity of fibers and the pores of fabrics. [ABSTRACT FROM AUTHOR]

In this study, we compare the effect of various precursor‐based graphene oxide (GO) nanofillers on enhancing the mechanical performance of E‐glass fiber‐reinforced epoxy resin composites (EGFPs). GO derived from bituminous coal (BC‐GO) and graphite (Gr‐GO) were dispersed into an epoxy resin matrix. The resulting mixture was combined with E‐glass fiber mats using vacuum‐assisted resin infusion molding. Notable improvements (38.9% in flexural strength, 22.9% in tensile strength, and 21.6% in impact strength) were observed in BC‐GO‐reinforced EGFPs at 0.25 phr loading of BC‐GO. The improvements for Gr‐GO‐reinforced EGFPs were 28%, 9.3%, and 6.8%, respectively. XRD analysis of BC‐GO showed a diffraction peak at 2θ = 20.9°. Except for this peak, no other crystalline peaks were observed when BC‐GO was incorporated into EGFPs. FTIR spectra of both composite samples, with or without the nanofiller, were similar due to the spectral peaks overlap. TEM demonstrated the exfoliated morphology of BC‐GO in EGFPs. These findings underscore the potential of BC‐GO as a cost‐effective reinforcement for polymer nanocomposites across various industrial applications, including the development of lightweight and strong materials for aerospace and automotive industries, protective coatings, petroleum, and aerospace production systems. Highlights: BC‐GO demonstrates superior mechanical performance compared to Gr‐GO in EGFPs.0.25 phr BC‐GO improves 38.9% flexural, 22.9% tensile, and 21.6% impact strengths.Beyond 0.25 phr, BC‐GO and Gr‐GO showed a decline in mechanical enhancement.Role of particle size, loading & adhesion to matrix analyzed using XRD, FTIR, and DLS.Coal‐GO is an attractive alternative nanofiller for EGFPs. [ABSTRACT FROM AUTHOR]

Glass fibers (GFs) are frequently employed as reinforcement fibers for polymer resins such as epoxy and polyester. The mechanical behaviors of GFs polymer composites are nevertheless constrained by weak interfacial adhesion between polymer matrix and GFs. Herein, we invented a cross‐linking modified sizing agent using polyethyleneimine and bisphenol A epoxy emulsion, and studied the effect of cross‐linking extent on GF surface characteristics and GF/epoxy interfacial adhesion. The treatment of GFs with cross‐linking modified sizing agent facilitated the formation of interpenetrating polymer networks in composites for strengthening interface interaction. The results show that the modified GFs have a rough surface and improved interfacial adhesion with epoxy matrix. When sizing agents with cross‐linking extent of the 23.0%, the GF/epoxy composites show advanced interfacial shear strength (IFSS) and transverse fiber bundle tension (TFBT) strength. This work demonstrates that the cross‐linking extent of sizing agent could regulate interfacial adhesion, which is a facile and promising strategy in reinforcing glass fiber polymer composites. Highlights: Crosslink the sizing agent to enhance GF mechanical properties was reported.GF surface energy was enhanced and thickness of GF/epoxy interphase increased.IFSS and TFBT strength of the GF/resin composites increased by 23.65% and 30.54%, respectively. [ABSTRACT FROM AUTHOR]

Glass fiber‐reinforced polymer‐matrix (GFRP) composites are used to manufacture devices such as radomes, electrical insulators, and radar‐absorbing structures, many of which are used in applications with strict mechanical and dielectric property requirements. As such, designs and properties of GFRP composite materials should be regularly improved to guarantee their safe operation and meet their constantly evolving application requirements. In this study, glass fiber (GF) particles and epoxy resin 128 (EP‐128) were used to manufacture high‐performance EP/GF‐X composites with GF particle contents ranging from 5% to 40%. An investigation into their mechanical and dielectric properties revealed that EP/GF‐20 composite specimens presented the best mechanical performance with their bending strength and modulus reaching 159.68 MPa and 6521.92 MPa, respectively, and an average dielectric constant of 4.862 within the 10–105 Hz frequency range. A theoretical analysis of the EP/GF‐X composite specimens' dielectric constants using classic dielectric models based on the Lichtenecker, Bruggeman, Jaysundere‐Smith, and Maxwell‐Garnett rule‐of‐mixture equations indicated that the dielectric model based on the Bruggeman rule‐of‐mixture equation provided the dielectric constants closest to the measured values with a maximum deviation of less than −0.321% for EP/GF‐40 composites. This study provides a feasible strategy to control the mechanical and dielectric properties of GFRP composites. Highlights: Glass fiber (GF) particles and epoxy 128 (EP‐128) resin were used to manufacture high‐performance glass fiber‐reinforced epoxy (EP/GF‐X) composites.The composite manufacturing process was carefully controlled to ensure uniform distribution and orientation of GF particles in the EP‐128 resin.The mechanical and dielectric properties of the manufactured EP/GF‐X composites were effectively tailored by controlling the content and distribution of GF particles in the EP‐128 resin matrix.The dielectric constants of the EP/GF‐X composites were measured experimentally and predicted using various theoretical dielectric models.The Bruggeman model provided the dielectric constants of the EP/GF‐X composites closest to the measured values. [ABSTRACT FROM AUTHOR]