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This paper presents a study of the flammability and thermal decomposition products of glass fiber-reinforced epoxy resin (GFRER) with the addition of cardanol-based phosphorus-containing benzoxazine monomer (CBz) and graphene and their combinations in different proportions (up to 20 wt.%). The addition of CBz alone or in combination with graphene resulted in an increase in the limiting oxygen index (LOI) and self-extinguishing in the UL-94 HB test. The flame-retardant samples had better tensile mechanical properties than the sample without additives. The differential mass-spectrometric thermal analysis (DMSTA) of the thermal decomposition products of GFRER without additives and with the addition of CBz and graphene was carried out. CBz addition promoted the thermal decomposition of high-molecular-weight products of epoxy resin decomposition in the condensed phase and at the same time decreased the time of release of low-molecular-weight thermal decomposition products into the gas phase. Graphene addition resulted in an increase in the relative intensities of high-molecular-mass peaks compared to GFRER without additives. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The usage of jute/cotton natural composites has surged in almost all fields of engineering due to their advantage of possessing high strength to weight ratio and biodegradability. This paper deals with the fabrication and investigation of mechanical properties of jute/cotton fiber reinforced epoxy composite which is relatively a hybrid composite. In this study, the composite is fabricated by a hand layup process followed by compression molding method with varying the number of layers of composite laminates also with different cutting angles. The composites are prepared with four different proportions of jute/cotton fibers. Various mechanical tests are conducted and the result shows that the 14-layer jute/cotton composite has optimum properties achieved and also observed that 90° has better properties than the others cutting angles. Statistical analysis of composites was done by ANOVA-table; based on mean effective plots, the optimum levels of parameters have been identified, and significant contribution of parameters is determined by analysis of variance Also, failure morphology analysis is done using a scanning electron microscope (SEM) through which the internal structures of the tested specimen are analyzed. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the dependence of the impact strength of impregnated 3D printed samples on the type of used hardener (PEPA and TETA) and the curing mode after impregnation for samples with different directions of plastic laying during the printing process. [ABSTRACT FROM AUTHOR]

Premature debonding between carbon fiber-reinforced polymer (CFRP) and concrete is a critical issue in structural reinforcement applications, often leading to a significant reduction in the load-carrying capacity of the system. This failure mode is typically initiated by inadequate adhesion at the interface, compromising the effectiveness of CFRP in enhancing the structural performance of concrete elements. To address these issues, this study explores the impact of silica sand on the mechanical and adhesion properties of epoxy resin composites. Initially, this paper investigates the physical and mechanical properties of epoxy resin composites by varying the ratios of silica sand from 0% to 15% by volume. Subsequently, it examines the effectiveness of these composites as sealing materials to enhance the bond strength between CFRP and concrete. Incorporating a 10% silica content improves the mechanical properties of the epoxy resin, with the tensile strength increasing from 29.47 MPa to 35.52 MPa and an elastic modulus from 4.38 GPa to 5.83 GPa. Furthermore, silica sand enhances the adhesion strength between CFRP and concrete, as confirmed by the increase in the pull-out force from 14.21 kN to 18.79 kN. Silica particles improve surface roughness and interlocking, contributing to a better load distribution and stress transfer at the interface. Therefore, silica-filled epoxy resin is an efficient material for CFRP–concrete bonding applications. [ABSTRACT FROM AUTHOR]

Epoxy resins were reinforced with different ZnO nanofillers (commercial ZnO nanoparticles (ZnO NPs), recycled ZnO and functionalized ZnO NPs) in order to obtain ZnO–epoxy composites with suitable mechanical properties, high adhesion strength, and good resistance to corrosion. The final properties of ZnO–epoxy composites depend on several factors, such as the type and contents of nanofillers, the epoxy resin type, curing agent, and preparation methods. This paper aims to review the preparation methods, mechanical and anti-corrosion performance, and applications of ZnO–epoxy composites. The epoxy–ZnO composites are demonstrated to be valuable materials for a wide range of applications, including the development of anti-corrosion and UV-protective coatings, for adhesives and the chemical industry, or for use in building materials or electronics. [ABSTRACT FROM AUTHOR]

This paper presents experimental results from three-point bending tests for a composite made of quadriaxial glass fiber fabrics and an epoxy resin. Two composites were tested, one with 8 layers and the other with 16 layers; both had the same matrix (the epoxy resin). Tests were carried out, using five different test rates from 10 mm/min to 1000 mm/min. The following parameters were recorded and calculated: Young's modulus, flexural stress, flexural strain, energy, force, and all four for the first peak. The experimental data reveal no sensitivity for these materials based on the test rates, at least for the analyzed range; but, the characteristics for the thicker composite, with 16 layers of fabric, are slightly lower than those for the thinner composite, with 8 layers. The results pointed out that, for the same thickness of composite, certain characteristics, such as stress at the first peak, the flexural modulus, strain at the first peak, and energy at the first peak, are not sensitive to the test rate in the range 10–1000 mm/min. The energy at the first peak is double for the 16-layer composite compared to the 8-layer composite, but the specific energy (as energy on cross-sectional area) has close values: 103.47 kJ/m2 for the 8-layer composite and 106.51 kJ/m2 for the 16-layer composite. The results recommend this composite for applications in components with resistance to bending or for low-velocity impact protection. [ABSTRACT FROM AUTHOR]

Copyright of Coatings & Protection / Tuceng yu Fanghu is the property of Coating & Protection Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Laser powder bed fusion (L-PBF) additive manufacturing technology can print multi-material parts with multiple functions/properties, and has great potential for working in harsh application environments. However, the metal blank formed by sintering metal powder material with binder added through L-PBF has an obvious porous structure and insufficient mechanical properties, and few studies have been conducted studying this. In this paper, epoxy resin was used to impregnate the blank of porous metal parts formed by L-PBF with iron-based powder material at a certain temperature, and a cross-linked curing reaction was carried out with three kinds of phenolic resin in different proportions under the action of a curing agent, so as to fill the pores and achieve the desired mechanical properties. The characteristic peaks of each group of epoxy resin were characterized using Fourier transform infrared spectroscopy (FT-IR) and H-nuclear magnetic resonance (1H-NMR) spectrums. The microstructure, decomposition temperature, and residue of four epoxy resin dispersion systems were analyzed with a scanning electron microscope (SEM), a thermal gravimetric analyzer (TGA), and derivative thermogravimetry (DTG). The results show that the density of the porous metal parts was obviously improved, the heat resistance temperature of the parts could reach 350 °C, and the tensile strength of the sample after EP2-1 impregnation was increased by 4–6 times after curing at 160 °C for 6 h. Therefore, the use of an epoxy resin dispersion system can increase the porosity of L-PBF porous metal parts, but can also significantly improve their mechanical properties, which can help them to meet the requirements of applications as model materials, biological materials, and functional materials to provide a feasible solution. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, h-BN-OH was obtained by hydroxylating h-BN and subsequently KH560 was grafted onto the surface of h-BN-OH, resulting in h-BN-KH560. The h-BN-KH560 was then dispersed in an epoxy resin (EP) to create an EP/h-BN-KH560 adhesive solution, with the content of h-BN-KH560 being varied. Graphene oxide (GO) was dispersed in PMIA precipitated fibers to produce PMIA/GO composite paper. Finally, the surface of the composite paper was evenly coated with the EP/h-BN-KH560 adhesive solution, and then PMIA/EP/GO/h-BN composites with different h-BN-KH560 contents and good thermal conductivity were prepared by hot pressing. The FTIR analysis confirmed the successful grafting of KH560 onto the surface of h-BN-OH. By utilizing h-BN-KH560 and GO as thermal conductive fillers, we achieved a higher thermal conductivity in the composite material, creating a "dual thermal conductivity network" compared to using a single filler. Additionally, the thermal conductivity increased as the content of h-BN-KH560 increased. At h-BN-KH560 contents of 20 wt%, 40 wt%, and 60 wt%, the thermal conductivities of the prepared PMIA/EP/GO/h-BN composites were 0.661 Wm−1K−1, 1.082 Wm−1K−1, and 1.206 Wm−1K−1, respectively. Importantly, the addition of the thermal conductive filler did not significantly affect the thermal stability of the composites. [ABSTRACT FROM AUTHOR]

This research paper presents a comparative experimental study on the impact of zinc oxide and zirconium dioxide nanomaterials on the chemical, mechanical, and crystalline properties of epoxy resin (diglycidyl ether of bisphenol-A). Nanomaterials were incorporated into the epoxy resin at three different concentrations (4%, 6%, and 8%) by weight. Results indicated enhanced properties of the epoxy resin, including tensile and compressive strengths, as well as improvements in chemical and crystalline characteristics, assessed through scanning electron microscope (SEM) and Fouriertransform infrared spectroscopy (FTIR). Notably, zirconium dioxide exhibited superior performance across all properties, enhancing tensile and compressive strengths by 67% and 50%, respectively. Zinc oxide, at the same concentrations, led to a 50% increase in tensile strength and a 40% increase in compressive strength. These outcomes were observed at the highest concentration (8%wt) of both nanomaterials and the pure epoxy resin. The presence of nanomaterials at this ratio promoted greater cohesion within the composite, as evidenced by SEM images of selected samples. SEM analysis highlighted the pivotal role of ZrO2 nanoparticles in improving epoxy integration, surface quality, crystallization, and imperfection removal, crucial factors for enhancing composite materials. FTIR analysis of the resin containing ZrO2 nanoparticles revealed shifts and alterations in peaks, indicating successful nanoparticle-epoxy interaction, resulting in notable structural changes. [ABSTRACT FROM AUTHOR]

In order to meet the increasing requirements of epoxy resin matrix materials for the electrical and electronics industry, this paper presents the design and synthesis of Si–Mg–B oxides using Mg, Si and B organic monomers, and preparation of Si–Mg–B/EP nanocomposites by ultrasonic dispersion and thermal curing. Mainly study the effect of composite oxide introduction on the dielectric properties of epoxy resin composites. With an increase in doping amount, the Si–Mg–B/EP nanocomposites show an increase in dielectric constant under working frequency test conditions; a decrease in dielectric loss followed by an increase, and the lowest value of 0.00238 is obtained at a doping amount of 8 wt%. The volume resistivity initially increases and then decreases, with the maximum value of 5.64 × 1016 Ω cm obtained at a doping amount of 8 wt%. Furthermore, the corona resistance life of Si–Mg–B/EP nanocomposites increases, with a value of 401.8 min obtained at a doping amount of 8 wt%, which is 4.65 times that of pure EP. And the morphology near the breakdown point of corona breakdown was analyzed. These results suggest that Si–Mg–B oxide is effective in improving the dielectric loss and corona resistance of epoxy resin. [ABSTRACT FROM AUTHOR]

Composite materials are a constantly evolving group of engineering materials, which has significantly changed their current, and potential role as structural materials over the past decades. Composites offer greater strength, stiffness, and less deformation to structural designers than previously available engineering materials. Resin matrix composites are widely used in the transportation, marine, aerospace, energy, and even sports industries. The manufacturing stage has a profound influence on the quality of the final product. This paper presents the production of composite materials by gravity casting in silicone moulds, using an epoxy/polyester resin matrix reinforced with wood chips and shredded glass fiber reinforced composite from recycled wind turbine blades. Some of the fabricated samples were degassed in a reduced-pressure chamber. The mechanical properties of the produced material were then examined. It was noted that the silicone moulds did not affect the resin self-degassing due to the large surface area to weight ratio, and the remaining small air bubbles had a limited effect on the mechanical properties of the samples. The filler used also played a significant role. Composites filled with crushed GFRC showed better strength properties than composites filled with wood chips. The conducted research is aimed at selecting materials for further testing with a view to their use in the manufacture of next-generation wood-based composite structural materials. [ABSTRACT FROM AUTHOR]

The use of asbestos in brake pads is being eliminated due to its carcinogenic effect. Due to this, there is a need for better alternative in the brake pad material to replace asbestos fibers. This leads to the development of more natural fibers/filler-based brake pads which are safer to the environment, cheaper, and readily available. Moreover, bio fillers-based brake pads have shown excellent performance compared to asbestos. This paper addresses the different composition of brake pad materials and manufacturing techniques. Common binders like epoxy resin, Phenolic resin-based brake pads were analyzed and its effect on the mechanical, tribological, and thermal performance were critically analyzed. Also, the performance of metal matrix-based brake pad has been analyzed in detail. It has been observed that utilizing natural fibers as a reinforcement provides an excellent braking performance compared to metallic and carbon fiber-based brake pads. This research will open new avenues towards "Net Zero." [ABSTRACT FROM AUTHOR]

Chemical grafting is commonly employed to functionalize carbon fiber (CF) surface to enhance the interfacial properties of CF reinforced polymer composites (CFRP) by forming a robust interface. However, an overly rigid interface layer can result in relatively poor interface toughness. To balance interfacial strength and toughness, this paper proposes an effective method to simultaneously strengthen and toughen the interface of CF/epoxy composites by grafting branched polyethyleneimine (PEI) on CF surface using hexachlorophosphazene (HCCP) as active intermediate, which features a rigid ring structure and six active P‐Cl groups. The introduction of PEI provided a large number of amine and imine groups on CF surfaces, which were contributive to improving surface wettability and reactivity of CF, thus resulting in strong chemical bonding between CF and epoxy matrix. Additionally, the long and flexible molecular skeleton of PEI constructed a rigid‐flexible composite interface, which could effectively reduce stress concentration and absorb impact energy. After surface modification with PEI, the interfacial shear strength and fracture toughness of CF/epoxy composite were increased to 89.9 MPa and 200.3 J m−2, by 64.3% and 149.7%, respectively, in compared with desized CF reinforced epoxy composites. Highlights: A rigid‐flexible interface was constructed between CF and epoxy resin.The interfacial strength and toughness of CFRP were synergistically improved.IFSS and interfacial toughness increased by 64.3% and 149.7%, respectively. [ABSTRACT FROM AUTHOR]

Highlights To improve the subpar lubricating performance of epoxy resin, this paper presents the preparation of a novel bimetallic phyllosilicate featuring a distinctive rice‐granular morphology, which incorporates nickel and iron metal cations through a facile hydrothermal process. These phyllosilicates were then integrated into the epoxy matrix to form composites. A comprehensive analysis of the target product validates the rationality of the synthesis strategy for the as‐prepared rice‐granular bimetallic nickel/iron phyllosilicate, demonstrating a homogeneous hierarchical structure with numerous tiny nanosheets of nickel/iron phyllosilicate grown in situ on the flat surfaces of the rice‐granular metal–organic frameworks. An adequate addition of nickel/iron phyllosilicates allows for excellent dispersion within the matrix and establishes strongly bonded interfaces, steadily increasing the elastic modulus and hardness. Notably, the average friction coefficients decrease from 0.515 for the pure resin to 0.450 for the composites when the filler content reaches 7%, indicating a significant solid lubrication effect. In contrast, adding just 1% nickel/iron phyllosilicate moderately improves wear resistance, elongation at break, and tensile strength. Furthermore, it was found that as the filler content increased, the weight loss rate was reduced by approximately 43.8%, while the residual char increased by 74.2%, significantly enhancing the thermal stability of epoxy composites at high temperatures. This study offers a promising approach to preparing self‐lubricated epoxy composites with favorable mechanical and thermal properties. NiFePS was successfully synthesized via a facile two‐step self‐polymerization. Excellent mechanical properties of composites could be achieved with low content of NiFePS. The friction coefficient and wear rate were lowered remarkably. The friction mechanism was solid lubrication. [ABSTRACT FROM AUTHOR]

In this paper, a dense and well‐adherent polydopamine‐Ti4O7/epoxy resin (PDA‐Ti4O7/EP) composite coating is successfully prepared. The modified grafting of Ti4O7 by polydopamine (PDA) is achieved through the coordination complexation of unstable catechol groups in PDA with coordination unsaturated Ti atoms in Ti4O7. The potentiodynamic polarization curve and electrochemical impedance spectroscopy test results show that the performance of the composite coating is improved compared with that of the pure epoxy coating, and the composite coating slows down the penetration of electrolytes and aggressive ions and improves the corrosion resistance. The composite coating with 2 wt.% PDA‐Ti4O7 filler shows the best corrosion resistance, and its |Z|0.01 Hz remains above 1011 Ω cm2 after 30 days of immersion in 3.5 wt% NaCl solution. This can be attributed to the good barrier property of PDA‐Ti4O7 filler, which carries NH2 and OH reactive groups, interacting with the resin and matrix to improve the dispersion of the filler and the adhesion of the composite coating. The NH2 group reacts with the epoxy group in the epoxy resin in a ring‐opening reaction, which avoids the agglomeration of the filler and the uniformly dispersed filler fills the pores in the coating due to curing to improve the denseness of the coating and give full play to the barrier property of the filler. At the same time, the hydrogen bonding between the filler and the OH group in the resin and the substrate increases the adhesion of the coating. In addition, the unstable catechol group in PDA chelates with iron ions to further improve the overall corrosion resistance of the coating. Highlights: A dense and well‐adherent PDA‐Ti4O7/EP coating is successfully prepared.PDA connect with Ti4O7 through coordination of catechol groups and Ti atom.PDA‐Ti4O7 are chemically bonded to the EP through a ring‐opening reaction.PDA‐Ti4O7 improves the crosslinking density and barrier ability of the coating. [ABSTRACT FROM AUTHOR]

In this paper, a dense and well‐adherent polydopamine‐Ti4O7/epoxy resin (PDA‐Ti4O7/EP) composite coating is successfully prepared. The modified grafting of Ti4O7 by polydopamine (PDA) is achieved through the coordination complexation of unstable catechol groups in PDA with coordination unsaturated Ti atoms in Ti4O7. The potentiodynamic polarization curve and electrochemical impedance spectroscopy test results show that the performance of the composite coating is improved compared with that of the pure epoxy coating, and the composite coating slows down the penetration of electrolytes and aggressive ions and improves the corrosion resistance. The composite coating with 2 wt.% PDA‐Ti4O7 filler shows the best corrosion resistance, and its |Z|0.01 Hz remains above 1011 Ω cm2 after 30 days of immersion in 3.5 wt% NaCl solution. This can be attributed to the good barrier property of PDA‐Ti4O7 filler, which carries NH2 and OH reactive groups, interacting with the resin and matrix to improve the dispersion of the filler and the adhesion of the composite coating. The NH2 group reacts with the epoxy group in the epoxy resin in a ring‐opening reaction, which avoids the agglomeration of the filler and the uniformly dispersed filler fills the pores in the coating due to curing to improve the denseness of the coating and give full play to the barrier property of the filler. At the same time, the hydrogen bonding between the filler and the OH group in the resin and the substrate increases the adhesion of the coating. In addition, the unstable catechol group in PDA chelates with iron ions to further improve the overall corrosion resistance of the coating. Highlights: A dense and well‐adherent PDA‐Ti4O7/EP coating is successfully prepared.PDA connect with Ti4O7 through coordination of catechol groups and Ti atom.PDA‐Ti4O7 are chemically bonded to the EP through a ring‐opening reaction.PDA‐Ti4O7 improves the crosslinking density and barrier ability of the coating. [ABSTRACT FROM AUTHOR]

Context: Traditional conductive adhesives based on epoxy resin system often encounter problems such as high brittleness and low heat resistance. Therefore, it is particularly important to improve the thermal and mechanical properties of the conductive adhesive. In this study, the effects of SWCNT-Ag and SWCNT fillers on the thermal properties of DGEBA/DETA/Ag conductive adhesive system were studied by using molecular dynamics to construct different cross-linking models. The final results show that the addition of SWCNT and SWCNT-Ag can significantly improve the thermal properties of the conductive adhesive. However, the nanosilver particles on the surface of SWCNT-Ag act as a bridge for the connection between SWCNT and Ag in the conductive adhesive. Therefore, SWCNT-Ag has a more positive impact on the thermal properties of DGEBA/DETA/Ag conductive adhesive system. Methods: In this paper, the influence of SWCNT-Ag on the thermal properties of traditional DGEBA/DETA/Ag conductive adhesive system was studied by using Materials Studio software. The volume shrinkage, glass transition temperature, thermal expansion coefficient, and thermal conductivity of the material were calculated based on COMPASS force field. The thermal conductivity is calculated by using reverse non-equilibrium molecular dynamics method. Finally, it is found that SWCNT-Ag has a positive effect on the thermal properties of the conductive adhesive system by comparing several groups of calculation data. [ABSTRACT FROM AUTHOR]

The present paper investigates the suitability of a vitrimeric epoxy resin for processing in the wet filament winding (WFW) process to manufacture fiber‐reinforced polymers (FRP). Comprehensive material characterization of a commercially available epoxy and vitrimeric resin based on disulfide exchange is carried out, and the processing in WFW is evaluated by analyzing thermomechanical, rheological, thermochemical properties, and chemical shrinkage. The direct comparison of a vitrimer and an established epoxy resin permits an indication of the processability and necessary adjustments in WFW. Based on the implications of modeling, we demonstrate the processing of the vitrimeric resin in the WFW process by increasing the resin bath temperatures. The vitrimer's and conventional resin's elastic modulus development and compression behavior were similar, highlighting the vitrimeric resin's potential. Further, the results confirm that established characterization and modeling routines can be transferred to vitrimeric resins and, therefore, path the way toward advanced process simulation of vitrimeric resin's processing. For this, the present publication gives essential advice for setting up testing schedules for characterizing epoxy vitrimers' processing behavior and their appropriate modeling. The present work underlines the potential of applying commercially available dynamic hardeners to manufacture recyclable and malleable FRP in established processes. Highlights: Material characterization and modeling of wet filament winding process.Wet filament winding of epoxy vitrimers.Thermomechanical and chemical shrinkage characterization of epoxy vitrimers.Rheological and kinetic modeling of epoxy vitrimer. [ABSTRACT FROM AUTHOR]

Ammonium polyphosphate (APP) is often used to construct intumescent flame retardant systems together, but it is faced with the problem of adding too much flame retardant. This paper envisions the construction of a modified APP flame retardant (TR@ZIFAPP) with a sandwich structure by the method of covering, which, in order to endow APP flame retardant with better flame retardant effect. By constructing a metal catalytic layer and a triazine carbon formation layer, the modified APP flame retardant has both catalytic carbon formation and phosphorus–nitrogen synergistic flame retardant functions. TR@ZIFAPP is expected to be used in flame‐retardant polymer composites with low addition requirements, adding it to epoxy resin (EP) reveals that the TR@ZIFAPP flame retardant could achieve the optimal flame retardant effect when the addition amount was only 3 wt%. The UL‐94 rating reached V‐0 grade, and the two off‐fire auto‐ignition time levels were only 0.7 s. The analysis of its flame retardant mechanism showed that the flame retardant in EP was mainly through the rapid formation of carbon to isolate oxygen and dilute the flammable gas to reach a strong flame retardant effect. [ABSTRACT FROM AUTHOR]

Epoxy resin (EP) has been widely utilized in electrical equipment and electronic devices due to its fascinating electric, thermal, and mechanical properties. However, the complex insulation structures of modern power devices in high-voltage direct current systems pose several challenges for EP-based dielectrics. The most significant among these challenges is the need for EP to stably operate under greater electric fields, requiring superior breakdown strength. This paper summarizes the key factors influencing the breakdown strength of EP and reviews reported methods for enhancing this property. Recognizing the limitations of existing approaches, we propose that the emerging technology of molecule design offers a potentially optimal solution for developing EP with enhanced breakdown strength. Furthermore, we anticipate the future development direction of EP with satisfactory insulation properties. We believe that enhancing the breakdown theory of solid dielectrics, exploring new research and development methodologies, and creating environmentally friendly EP with high performance are primary focus areas. We hope that this paper will offer guidance and support for the future development of EP with superior breakdown strength, proving valuable in advancing EP-based dielectrics.

Abstract Fibre reinforced polymer composites have become a new generation of structural materials due to their unique advantages such as high specific strength, designability, good dimensional stability and ease of large-area monolithic forming. However, the problem of interfacial bonding between the resin matrix and the fibres limits the direct use of reinforcing fibres and has become a central difficulty in the development of basalt fibre-epoxy composites. This paper proposes a solution for enhancing the strength of the fibre-resin interface using maize starch nanocrystals, which are highly yield and eco-friendly. Firstly, in this paper, corn starch nanocrystals (SNC) were prepared by hydrolysis, and were deposited on the surface of basalt fibers by electrostatic adsorption. After that, in order to maximize the modification effect of nano-starch crystals on the interface, the basalt fiber-epoxy resin composite samples were prepared by mixing in a pressureless molding method. The test results shown that the addition of basalt fibers alone led to a reduction in the strength of the sample. Deposition of 0.1 wt% SNC on the surface of basalt fibers can make the strength consistent with pure epoxy resin. When the adsorption amount of SNC reached 0.5 wt%, the tensile strength of the samples was 23.7% higher than that of pure epoxy resin. This is due to the formation of ether bond homopolymers between the SNC at the fibre-epoxy interface and the epoxy resin, which distorts the originally smooth interface, leading to increased stress concentration and the development of cracks. This enhances the binding of basalt fibers. The conclusions of this paper can provide an effective, simple, low-cost and non-polluting method of interfacial enhancement modification.

AbstractThe continuous integration and refinement of electronic equipment results in the more stringent requirements for epoxy resin (EP) based materials, such as excellent heat dissipation and low coefficient of thermal expansion (CTE). In order to improve the dispersion of silica powder (SP) in EP and thus expand the application of EP in the field of electronic packaging, our research described in this paper adopted the KH-550 coupling agent to modify the surface of SP (m-SP). The effects of KH-550 coupling agent on the characteristics of the composites were investigated in terms of thermal, rheological, electrical insulation and mechanical properties. The results showed that when the content of KH-550 was 2 wt% of the fillers, the best modification effect was achieved, and the surface properties of the fillers were changed accordingly. In particular, the materials filled with m-SP exhibited lower viscosity end, better mechanical and electrical insulation properties. It was also found that the adding of the KH-550 had different effects on the thermal degradation, dynamic thermo-mechanical properties and the thermal deformation behavior of the materials. According to our study, the thermal conductivity and the CTE of m-SP/EP filled with 70 wt% of modified fillers were 0.787 W/m.K and 28.3 ppm/°C respectively, corresponding to a significant thermal conductivity improvement and low CTE. [ABSTRACT FROM AUTHOR]

In this paper glass/chicken feathers reinforced epoxy composite and glass/chicken feathers reinforced polyester composite was prepared in the laboratory at different percentage of the glass and chicken feathers. Tensile properties, flexural properties, shore hardness and impact strength of the glass/chicken feathers reinforced epoxy composite and glass/chicken feathers reinforced polyester composite was studied experimentally and compared at different percentage of the glass and chicken feathers. The composite will be used in humid and corrosive environment; therefore, water absorption and acid corrosion test were performed. To understand the degradation behaviour of the composite, soil test was performed. Scanning electron microscopy analysis was carried out to find the fracture and interfacial characteristics of the composites after tensile test. This hybrid composite can be used in automobile, structural and defense sector. [ABSTRACT FROM AUTHOR]

In this paper, the rheological, electrical and mechanical properties of silver paste with different blends of epoxy resin and polyester resin were studied. The thixotropy and thixotropy recovery rate of resin silver paste were studied by rheometer, and the effect of rheology on printing film was discussed. In situ curving resistance test method was used to monitor the change of thermal curing resistance of silver resin paste. The results showed that the content of epoxy resin in silver paste had great influence on the resistance. The adhesion strength of resin silver paste on Al2O3 substrate was evaluated by the thrust test method, and the thermal impact performance of resin silver paste was evaluated. The results showed that when the ratio of epoxy resin to polyester resin was 1:0.6, the viscosity of C-1 silver paste was moderate, the thixotropic recovery rate was 58.03% after 10 s, and the printing surface was flat. After curing at 200 ℃ for 30 min, the resistance is about 2 Ω, the adhesion strength is about 10 N/mm², and the adhesion strength is not significantly deteriorated after thermal shock at 260 ℃. The comprehensive performance is better, and it is suitable for the process requirements of electronic components. [ABSTRACT FROM AUTHOR]

In this paper, the effects of different polyester resins, epoxy resins, fillers, different additives and extrusion processes on the surface scratch resistance of polyester epoxy matt powder coating and the improvement of surface bright marks are described. By adjusting the formula and process, the anti-scratch performance of the coating is improved. meanwhile, the bright mark defect on surface of coating is modified, which is useful to ensure product quality. [ABSTRACT FROM AUTHOR]

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Users of the microbond test assume that a microbond resin droplet’s properties are equivalent to a macroscale specimen. However, there is currently no standardised methodology for determining the cure state of droplet specimens used in the microbond test. In this paper, we present a technique for microbond test users to better understand the properties of thermoset droplet specimens. Utilising a conventional benchtop spectrometer, a novel sample preparation technique involving curing epoxy droplets on thin-steel filaments allowed for high-throughput determination of the microbond droplet cure state. The parity between steel filament and glass fibre microbond samples was confirmed by infrared microspectroscopy. It is shown that cure schedules used in manufacturing composite parts produced microbond droplets with degrees of cure lower than that of bulk matrix specimens subjected to an identical thermal history. Testable microbond droplets could only be prepared for commercial resin systems when introducing a room temperature pre-curing time of at least 2 h. It is concluded that microbond testing should be supported by some droplet cure state characterisation methods to ensure that interfacial effects are not artefacts of droplet sample preparation. [ABSTRACT FROM AUTHOR]

In this paper, a safe, non-toxic, and low-cost method was adopted to modify ultra-high molecular weight polyethylene (UHMWPE) fibers. gallic acid (GA) and polyethyleneimine (PEI) were co-deposited on the surface of UHMWPE fibers by Michael addition and Schiff base reaction in an alkaline solution with pH 8.5. The structure and properties were analyzed and characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analyzer (TG), etc. The morphology of the UHMWPE fibers and the degree of firmness of the surface coatings were observed by Scanning Electron Microscope (SEM), and the effects of different mass ratios of GA-PEI on the UHMWPE fibers were investigated. The results showed that the surface active functional groups of the modified UHMWPE fibers increased, and the bending properties and interfacial shear strength of the composites with epoxy resin were significantly improved, with the bending strength and interfacial shear strength increased by 33.1% and 45.9%, respectively. [ABSTRACT FROM AUTHOR]

Rapid solidification molding is one of the main low‐cost forming methods for composite materials, and the reasonable selection of the solidification molding process is the key to achieving material performance. The curing system used in this paper is the widely used, inexpensive, and readily available epoxy resin (WSR618) and the transparent, colorless, and less toxic 593 curing agent, which cures at room temperature. Through the study of various temperature formulations, a rapid curing system was determined that has a 10‐min cure at 80°C. The results showed that when the mass ratio of epoxy (EP) resin to curing agent was 5:1, the curing system was selected at 80°C for 10 min, and the bending strength could reach 100.19 MPa, and the impact strength could reach 12.82 kJ/m2. However, the difficulty caused by quick solidification was a reduction in mechanical characteristics, which required modification. Microcrystalline cellulose is cheap and readily available and widely available, so microcrystalline cellulose (MCC) was chosen for modification in this study. The experimental results showed that the addition of MCC reduced the fracture brittleness of EP composite materials. When 0.75% MCC was added, the bending and tensile strengths reached 116.88 and 52.53 MPa, respectively, which were 16.66% and 18.74% higher than unmodified EP. The elongation at break reached 11.57%, which is 14.13% higher than unmodified. [ABSTRACT FROM AUTHOR]

Corrosion is a significant challenge in many practical applications, leading to the deterioration of metal infrastructure and equipment. A literature review indicates that various epoxy resins (ERs) and epoxy phenolic resins (EPRs) based coatings are available and are effectively applied on steel and aluminum surfaces for protection against a corrosive environment. The corrosion-resistant performance of ERs and EPRs can be further improved by incorporating numerous chemical compounds through improved bonding, such as inorganic compounds and carbon-based materials, e.g., zinc oxide (ZnO), titanium dioxide (TiO2), silicon dioxide (SiO2), carbon fiber, carbon nanotube (CNTs) and graphene oxide (GO). Surface heterogeneity (surface pores) of coatings contributes to reduced corrosion protection as corrosion species can diffuse to these inconsistencies and break the coating structure of the organic coating. However, after over a hundred years of research and development, the degradation/failure mechanism of organic coatings is still under study. This paper provides an overview of the current state-of-the-art knowledge of the numerous protective organic coatings and coating approaches and examines coating performance and mechanism for the coating degradation and failure in a corrosive environment. Finally, a summary is presented on the understanding of the mechanisms and challenges associated with, and critical factors influencing, coating durability and predictive formulation against coating damage. [ABSTRACT FROM AUTHOR]

Self-luminous pavement materials can autonomously absorb solar energy and emit light at night, offering a novel approach to improving nighttime road visibility and reducing energy consumption. Despite their potential, current self-luminous pavement coatings face challenges related to insufficient durability and anti-skid properties. To address this, this paper aims to develop a novel sustainable and durable self-luminous pavement material and thin layer. The development involved optimizing high-transparency epoxy resin based on mechanical properties and ultraviolet aging resistance, as well as selecting long afterglow materials based on luminous performance. Subsequently, a novel self-luminous pavement thin layer, comprising an anti-skid layer, a bonding layer, a self-luminous layer, and a sub-bonding layer, was proposed and tested. The results indicate that this novel self-luminous thin layer maintains a brightness level of 4–6 mcd/m2 after 6 h of light emission, which is still a bright level for the human eye. Additionally, it shows robust performance against ultraviolet aging, water damage, and long-term abrasion. The material cost of this thin layer is approximately 32.00 USD/m2, offering an economic advantage over mixture and pouring-in type, and it also provides benefits such as energy savings, improved traffic safety, and enhanced aesthetic appeal of scenic roads. Future efforts should focus on analyzing the economic benefits of these functions to better understand the full lifecycle advantages of this innovative material. In general, the novel durable self-luminous thin layer proposed in this study provides a practical and sustainable solution for self-luminous pavements. • A novel thin-layer structure and materials for self-luminous pavement is proposed. • The properties of different epoxy resins and long afterglow materials were analyzed. • Verified the afterglow brightness and durability of the self-luminous pavement thin-layer. [ABSTRACT FROM AUTHOR]

Corrosion of metallic materials can have a detrimental impact on their performance, leading to a shortened service life of engineering equipment and posing risks to both people and the environment. This paper presents a novel epoxy resin (EP)-based composite coating (PFANI-GO/EP) that offers triple corrosion protection functions: barrier, passivation, and corrosion inhibition. Perfluorooctanoic acid-doped polyaniline modified graphene oxide (PFANI-GO) demonstrates superhydrophobicity, effectively enhancing the coating's barrier ability against corrosive substances. The combination of PANI and perfluorooctanoic acid (PFOA) in composite materials aids in the formation of a passivation film and hydrophobic layer, which prevent metal corrosion. After a 15-day immersion in brine, the PFANI-GO/EP coating demonstrates the highest impedance modulus of 1 × 109 Ω·cm2 at 0.01 Hz, compared to pure EP coating, GO/EP coating, and PFANI/EP coating. Therefore, due to its corrosion resistance and prolonged corrosion aging time, PFANI-GO/EP coating shows promising potential for mitigating metal corrosion. • PFANI-GO with superhydrophobicity enhances the barrier effect of coatings against corrosive media. • PFANI-GO with passivation and corrosion inhibition properties is designed as a multifunctional nanofiller. • PFANI-GO/EP composite coatings with excellent barrier, passivation and corrosion inhibition properties. • The PFANI-GO/EP composite coating still possesses excellent corrosion protection properties after prolonged immersion at 3.5 wt%. [ABSTRACT FROM AUTHOR]

Fire dangers have grown to be a serious potential issue that could endanger people's health and safety in recent years. A lot of emphasis has been paid to the employment of straightforward techniques to create multifunctional synergistic flame retardants in order to create multifunctional flame retardant epoxy curing compounds. In this paper, a flame retardant TFD with DOPS and phenoxytriazine as flame retardant core groups was synthesized by molecular structure design using cyanuric chloride, p-hydroxybenzaldehyde, and DOPS as the raw materials, and it was melt blended with EP to construct a flame retardant thermoset resin EP/TFD. The results show that the addition of only 10% TFD enables EP to pass the UL-94 V-0 test with an LOI of up to 35.3%. Moreover, TFD was able to effectively reduce the peak heat release rate, total heat release, and fire growth index of epoxy curing compounds, whereas the fire performance index was significantly improved compared with that of pure EP, indicating that TFD could confer higher fire safety to EP. Moreover, TFD can significantly enhance the mechanical toughness of EP with appropriate additive amount. That is, the maximum rise compared with the pure EP enhancement of 46.3%. This program serves as a valuable resource for the advancement of halogen-free flame retardants with superior efficiency. [Display omitted] • Homemade sulfurized DOPO flame retardant. • Synthesis of bifunctional group synergistic flame-retardant epoxy thermoset resins based on sulfurized DOPO flame retardants. • Low dosage, excellent flame retardant performance. • EP/TFD has good thermal stability; fire safety. • Excellent char formation and mechanical toughness. [ABSTRACT FROM AUTHOR]

Natural fibre-reinforced polymer composite (NFRPC) has been introduced as one of the solutions to overcome the ecological and environmental problems accompanying the widespread usage of polymeric materials in every facet of life. However, the organic nature of both natural fibres (NFs) and polymers increases their flammability behaviour, and this, in turn, limits their application. In this regard, this work concentrates on studying the effect of adding flame retardants (FR) to jute-reinforced epoxy composites (JRECs), either by treating the jute fabric with diammonium phosphate (DAP) or adding DAP powder to the epoxy resin matrix on the flame retardancy performance as well as the mechanical properties. The results showed that the effect of the incorporation method of DAP either to jute fabric or to resin matrix has a significant difference on the flammability test results at low concentrations; however, at higher concentrations, the flame retardancy performance is not affected by the technique of adding FR to the composite system. On the other hand, the mechanical properties are significantly affected by the method of incorporating FR to JRECs at all concentrations. Moreover, the results obtained from JRECs with FR systems were evaluated and compared with the literature by constructing selection charts that relate the flame retardancy level to mechanical properties. [ABSTRACT FROM AUTHOR]

There are many kinds of hot-mixed epoxy resins on the market with uneven performance, which makes it difficult to select the excellent performing material. This study investigated the effects of glass transition temperature (Tg) on epoxy resins, epoxy asphalts, and epoxy asphalt mixtures, aiming to confirm the Tg is an effective way to quickly select optimum epoxy resin materials. Specifically, the macromechanical properties, microproperties, and rheological properties of epoxy resins, epoxy asphalts, and epoxy asphalt mixtures were evaluated by a tensile and viscosity test, a dynamic mechanical thermal analysis test, a scanning electron microscope (SEM) test, and a dynamic shear rheometer test. Results indicate that the performances of epoxy resins, epoxy asphalts, and epoxy asphalt concretes have closely related with Tg. With Tg increasing, the tensile strength, Marshal stability, and dynamic stability are increased, while the elongation at the break, flexural tensile strains, fracture energy, and viscosity are decreased. In addition, the enhanced Tg may boost the deformation resistance of epoxy asphalts. Furthermore, the activity energy of HB, CW-HBP, and TAF is −42.86 kJ/mol , −40.79 kJ/mol , and −53.97 kJ/mol respectively, which demonstrate that Tg has no correlation with the activity energy. Besides, according to the SEM test result, the lower Tg can make epoxy resins experience ductile fracture, while higher Tg can make the HB epoxy resin experience brittle fracture. Finally, the Tg can be used to qualitatively compare and quickly select the optimum hot-mix epoxy resin used in long-span steel bridge deck pavement. [ABSTRACT FROM AUTHOR]

In this study, a microbial–enzymatic strategy was pursued to address the challenge of degrading thermoplastic and thermosetting polymers. Environmental microorganisms were isolated, and their enzymatic activities were assessed using colorimetric assays to evaluate their potential for producing enzymes capable of degrading these polymers. Microorganisms demonstrating higher activity in the enzymatic assays were selected for a 30-day biodegradation experiment, in which epoxy resins, polyethylene terephthalate, or polystyrene served as the sole carbon source. The effectiveness of biodegradation was assessed through the ATR-FTIR analysis of the chemical composition and the SEM examination of surface characteristics before and after degradation. The results indicated that thermoplastic compounds were more susceptible to microbial degradation, exhibiting greater changes in absorbance. In particular, PET treated with Stenotrophomonas sp. showed the most significant efficacy, achieving a 60.18% reduction in the area under the curve with a standard error of ± 3.42 when analyzed by FTIR spectroscopy. Significant alterations in surface morphology were noticed in thermoplastic compounds. In contrast, thermosetting compounds demonstrated lower reactivity, as evidenced by the absence of band shifts in FTIR spectra and minor changes in bond absorbance and surface morphology. [ABSTRACT FROM AUTHOR]

A silica/aminated kaolin (SiO2@AK) composite was prepared by modifying kaolin and loading silica, using intercalation complex method and sol–gel method. Quantitative composites were dispersed in epoxy resin to obtain a silica/aminated kaolin/epoxy resin composite coating (SiO2@AK/EP) on stainless steel. The results showed that the thickness of the dry coating was approximately 110 ± 10 μm, and the surface was flat without evident agglomeration. As the SiO2@AK composite was introduced, the water contact angle increased from 40° to 88°, the average surface roughness of the prepared composite coating was reduced from 10.3 nm to 3.19 nm, and the corrosion current decreased by nearly three orders of magnitude. After the coating was soaked in 3.5 wt% NaCl solution for 30 days, the impedance modulus of the composite coating remained above 2.511 × 109 Ω cm2, reflecting that the introduction of the composite could effectively improve the anticorrosion property of the epoxy resin. [ABSTRACT FROM AUTHOR]