bisphenol-A Epoxy Research Articles

Molecular dynamics investigation of epoxy resin adsorption mechanisms on clay surfaces and the mechanical properties of epoxy resin-clay

The strength of natural clay can be improved with epoxy resins. However, nanoscale curing mechanisms remain poorly understood, which is essential for enhancing stability. In this study, molecular dynamics simulation was employed to calculate the quantity of interface hydrogen bonds, adsorption energy, radius of gyration, and mechanical properties of clay cured by diglycidyl ether of bisphenol-A epoxy resin (DGEBA), diglycidyl ether 4,4’-dihydroxy diphenyl sulfone (DGEDDS), and Aliphatic epoxidation of olefin resin (AEOR). Adsorption behavior and mechanical properties of the clay cured by three epoxy resins were investigated: (1) The chain structure of AEOR led to 18.2% more hydrogen bonds than DGEBA and 59.1% more than DGEDDS. (2) The simulated adsorption energies for DGEBA, DGEDDS, and AEOR with kaolinite were 92.59, 98.25, and 116.87 kcal·mol−1, respectively. (3) The bulk and shear modulus of kaolinite increased by 4.93% and 4.80% when using AEOR. The interface stability and mechanical properties of kaolinite were also improved through strong hydrogen bonds and high adsorption energy. (4) The improvement in Young’s modulus of kaolinite was most significant with AEOR, followed by DGEDDS. AEOR excelled in the Z direction, while DGEDDS excelled in the X and Y directions. This research provided a theoretical foundation to effectively improve the properties of clay using epoxy resins.

Synergistic Effects of Liquid Rubber and Thermoplastic Particles for Toughening Epoxy Resin

This study aims to investigate the toughening effects of rubber and thermoplastic particles on epoxy resin (EP), and to understand the mechanism underlying their synergistic effect. For this purpose, three EP systems were prepared using diglycidyl ether of bisphenol-A (DGEBA) epoxy resin (E-54) and 4,4-Diamino diphenyl methane (Ag-80) as matrix resin, 4,4-diaminodiphenyl sulfone (DDS) as a curing agent, and phenolphthalein poly (aryl ether ketone) particles (PEK-C) and carboxyl-terminated butyl liquid rubber (CTBN) as toughening agents. These systems are classified as an EP/PEK-C toughening system, EP/CTBN toughening system, and EP/PEK-C/CTBN synergistic toughening system. The curing behavior, thermal properties, mechanical properties, and phase structure of the synergistic-toughened EP systems were comprehensively investigated. The results showed that PEK-C did not react with EP, while CTBN reacted with EP to form a flexible block polymer. The impact toughness of EP toughened by PEK-C/CTBN was improved obviously without significantly increasing viscosity or decreasing thermal stability, flexural strength, and modulus, and the synergistic toughening effect was significantly higher than that of the single toughening system. The notable improvement in toughness is believed to be due to the synergistic energy dissipation effect of PEK-C/CTBN.

Effects of Varying Nano-Montmorillonoid Content on the Epoxy Dielectric Conductivity

This study investigates the correlation between the interface structure and macroscopic dielectric properties of polymer-based nanocomposite materials. Utilizing bisphenol-A (BPA) epoxy resin (EP) as the polymer matrix and the commonly employed layered phyllosilicate montmorillonoid (MMT) as the nanometer-scale dispersive phase, nano-MMT/EP composites were synthesized using composite technology. The microstructure of the composite samples was characterized through XRD, FTIR, SEM, and TEM. Changes in the morphology of the nanocomposite interface were observed with varying MMT content, subsequently impacting dielectric polarization and loss. Experimental measurements of the dielectric spectrum of the nano-MMT/EP were conducted, and the influence of the material interface, at different nano-MMT contents, on the dielectric relaxation was analyzed. The study delves into the effect of the nanocomposite interface structure on ion dissociation and migration barriers, exploring the ionic conductivity of nano-MMT/EP. Lastly, an analysis of the impact of different nano-MMT contents on the dielectric conductivity is presented. From the experimental results, the arranging regularity of polymer molecules in the interface area raises. In the matrix, the ion migration barriers decrease significantly. The higher the MMT content in the interface, the lower the migration barrier is. Until the MMT content exceeds the threshold, the agglomerated micro-particles form, which decreases the polymers’ space distribution regularity, and the ions migration barrier raises. According to the changes in the rule of the ions migration barrier with the composite interface structure content, the reason for dielectric conductivity changes can be judged.

Thermal conductivity of epoxy/multilayered graphene composites prepared with different curing agents

Epoxy/multilayer graphene (ML-graphene) composites were prepared using different curing agents to control the graphene dispersion by changing the curing reactivity. With increasing initial reactivity, the aggregation size of the ML-graphene decreased and their thermal conductivity increased. In particular, the thermal conductivity of the composite prepared with p-phenylenediamine showed a maximum value of 1.46 W/(m·K) at 25 wt% ML-graphene loading because of the highest initial curing reactivity. The application of a magnetic field led to graphene alignment along the applied field, resulting in two times higher thermal conductivity than that of the corresponding system without magnetic field. The relationship between the interfacial affinity for epoxy/graphene and thermal conductivity was also investigated. As a result, resulting in a biphenyl epoxy composite showed higher thermal conductivity (6.17 W/(m·K)) than that of the bisphenol-A epoxy composite. This is derived that the π-conjugated and planar structure of biphenyl epoxy can easily interact with the surface of graphene.

Cross-Linking Reaction of Bio-Based Epoxy Systems: An Investigation into Cure Kinetics.

The cure kinetics of various epoxy resin mixtures, comprising a bisphenol epoxy, two epoxy modifiers, and two hardening agents derived from cardanol technology, were investigated through differential scanning calorimetry (DSC). The development of these mixtures aimed to achieve epoxy materials with a substantial bio-content up to 50% for potential automotive applications, aligning with the 2019 European Regulation on climate neutrality and CO2 emission. The Friedman isoconversional method was employed to determine key kinetic parameters, such as activation energy and pre-exponential factor, providing insights into the cross-linking process and the Kamal-Sourour model was used to describe and predict the kinetics of the chemical reactions. This empirical approach was implemented to forecast the curing process for the specific oven curing cycle utilised. Additionally, tensile tests revealed promising results showcasing materials' viability against conventional counterparts. Overall, this investigation offers a comprehensive understanding of the cure kinetics, mechanical behaviour, and thermal properties of the novel epoxy-novolac blends, contributing to the development of high-performance materials for sustainable automotive applications.

Mechanical and Thermal Properties of Epoxy Resin upon Addition of Low-Viscosity Modifier.

Thermoset-based polymer composites containing functional fillers are promising materials for a variety of applications, such as in the aerospace and medical fields. However, the resin viscosity is often unsuitably high and thus impedes a successful filler dispersion in the matrix. This challenge can be overcome by incorporating suitable low-viscosity modifiers into the prepolymer. While modifiers can aptly influence the prepolymer rheology, they can also affect the prepolymer curing behavior and the mechanical and thermal properties of the resulting matrix material. Therefore, this study investigates the effects that a commercial-grade low-viscosity additive (butyl glycidyl ether) has on a common epoxy polymer system (diglycidyl ether of bisphenol-A epoxy with a methylene dianiline curative). The weight percentage of the modifier inside the epoxy was varied from 0 to 20%. The rheological properties and cure kinetics of the resulting materials were investigated. The prepolymer viscosity decreased by 97% with 20 wt% modifier content at room temperature. Upon curing, 20 wt% modifier addition reduced the exothermic peak temperature by 12% and prolonged the time to reach the peak by 60%. For cured material samples, physical and thermo-mechanical properties were characterized. A moderate reduction in glass transition temperature and an increase in elastic modulus was observed with 20 wt% modifier content (in the order of 10%). Based on these findings, the selected material system is seen as an expedient base for material design due to the ease of processing and material availability. The present study thus provides guidance to researchers developing polymer composites requiring reduced prepolymer viscosity for successful functional filler addition.

Durability test study of laminated specimens for large glass fiber protective structures in seawater

The mechanical properties of glass fiber composite structures prepared by vacuum forming manufacturing process are influenced by various factors and have a certain degree of dispersion, resulting in unclear durability characteristics when applied in corrosive seawater engineering. Firstly, a variety of resin materials for underwater protective structures are tested for seawater degradation, and excellent resins that can still ensure the structural load-bearing capacity and stability after immersion are selected. Secondly, based on relevant standards and specifications, the article conducted seawater immersion aging tests at room temperature and accelerated seawater immersion aging tests at 60°C on glass fiber specimens of 430 epoxy bisphenol vinyl resin and 1967 polycyclic pentadiene resin. Finally, the degradation characteristics of strength, modulus, and impact toughness of the specimens were obtained through a series of mechanical property tests, such as bending, compression, shear and impact, under different aging time periods in room temperature and 60°C seawaters, respectively. The article summarizes the differences in the durability and mechanical properties degradation of large glass fiber protective structures with different resins during seawater immersion.

Preparation of Langmuir-Blodgett composite films based on Bisphenol fluorene and Epoxy bisphenol fluorene with photovoltaic properties

The Langmuir-Blodgett (LB) technique can be used to obtain highly ordered arrangement and assembly of high polymer molecular chains, and the obtained LB films exhibit the controllable structures and special physicochemical properties. Here, we successfully prepared the composite LB films based on bisphenol fluorene (BPF) and epoxy bisphenol fluorene (DGPF) by LB technique, as well as explored the microstructures of the composite LB films by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The different aggregation states of various dye molecules in the composite LB films are investigated by UV–vis. Interestingly, the composite LB film electrodes exhibit promising photoelectrochemical properties. In particular, BPF/MB and DGPF/MB LB films show better photoelectric conversion efficiency. It is attributed to the ordered arrangement of BPF and DGPF and their effective aggregation with dye molecules, which improves the light absorption ability and charge transfer efficiency of the materials. Therefore, the prepared LB films based on the synthetic polymers BPF and DGPF are expected to play an important role in microelectronics.

Dielectric Characterization and Machine Learning-Based Predictions in Polymer Composites with Mixed Nanoparticles

Our research described in this manuscript investigated the dielectric properties and structural characteristics of Bisphenol-A epoxy resin composites infused with various concentrations (5 wt.%, 10 wt.%, and 15 wt.%) of hybrid nanofillers, namely alumina (Al2O3) and zinc oxide (ZnO). Ultrasonic dispersion was utilized to integrate the nanofillers into the resin matrix. Structural properties were assessed using X-ray diffraction (XRD), which confirmed the presence of the Al2O3 and ZnO nanoparticles within the epoxy matrix. Dielectric properties were measured over a frequency range of 104 Hz to 2 MHz. The results provide new insights into the polarization mechanisms and structural characteristics of these composites, highlighting their potential for enhanced dielectric performance in high-frequency applications. To further understand and predict these dielectric properties, the CatBoost and LightGBM regression models were employed to predict the dielectric constant (ε'), loss tangent (tan δ), and AC conductivity (σac) of these composites. The models demonstrated strong predictive accuracy, with performance metrics, including Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and R-squared (R2), indicating the robustness and accuracy of the models in predicting the dielectric properties of the composites. The study’s findings underscore the significant potential of Bisphenol-A epoxy resin composites with hybrid nanofillers for high-frequency dielectric applications.

Enhanced dielectric properties of titanium dioxide/epoxy nanocomposites with different nanofiller shape

In this study, three different shapes of titanium dioxide, namely nanoparticles, nanowires, and nanosheets, were blended into a bisphenol-A epoxy resin. The dielectric properties of the epoxy nanocomposites were measured to investigate whether the shape of the nanofiller affects the behavior of the epoxy resin. Firstly, titanium dioxide nanowires and titanium dioxide nanosheets were synthesized. Secondly, three different fillers were added to the epoxy resin to obtain three types of nanocomposites. Finally, the performance of these epoxy nanocomposites were evaluated including complex permittivity dependence on frequencies, DC volume resistivity, AC breakdown strength, and thermally stimulated discharge current. Results indicate that different shapes of titanium dioxide fillers have varying effects on the characteristics of the epoxy resin. It was observed that the shape of the nanofiller influences the amount of trapped charge in samples which subsequently impacts the overall performance of the epoxy composite.

Enhanced dielectric properties of titanium Dioxide/Epoxy nanocomposites with different filler crystal form

In this work, two different types of titanium dioxide, anatase and rutile, were blended into a bisphenol-A epoxy resin. The dielectric properties of epoxy nanocomposites were measured to investigate whether the filler crystal form affects the behaviors of epoxy resin. All nanoparticles have a same size of ∼ 60 nm and the content of the nanocomposites is from 1 to 4 wt%. The dielectric properties of epoxy nanocomposites, including complex permittivity dependence on frequencies, volume resistivity, and breakdown strength were measured. Although the band gap of anatase-type titanium dioxide is smaller than that of rutile-type titanium dioxide, its epoxy nanocomposite has a higher volume resistivity and a higher breakdown strength at each filler content. The anatase-type titanium dioxide is more favorable than rutile-type titanium dioxide to improve the dielectric properties of epoxy resin.

Synthesis and Characterization of Bisphenol-C Epoxy Crotonate and Its Fiber-Reinforced Composites

Bisphenol-C epoxy crotonate resin was synthesized by reacting 8.09g epoxy resin of bisphenol- C, and 2.15g crotonic acid using 25 mL 1,4-dioxane as a solvent, and 1 mL triethylamine as a catalyst at reflux temperature for 1-6 h. Solid epoxy crotonate (ECCR) is highly soluble in common organic solvents. ECCR was characterized by its acid (24.5-1.5 mg KOH/g) and hydroxyl (504.5-678.4 mg KOH/g) values. The structure of ECCR is supported by FTIR and 1HNMR spectroscopic methods. A DSC endothermic transition at 229oC indicated melting followed by thermal polymerization of ECCR. ECCR is thermally stable up to 320oC and follows three-step degradation kinetics. The first step followed first-order degradation kinetics, while the second and third steps followed one-half-order degradation kinetics. High values of kinetic parameters suggested the rigid nature of the crosslinked resin. Jute-, Glass- and Jute-natural fiber-ECCR composites showed moderate tensile strength, flexural strength, electric strength, and volume resistivity due to the rigid nature and poor interfacial adhesion of the composites. J-ECCR and G-ECCR composites showed high water absorption tendency and excellent hydrolytic stability against water, 10% aq. HCl and 10% aq. NaCl and even in boiling water. Mechanical and electrical properties and water absorption tendency of the composites indicated their usefulness as low load-bearing housing and insulating materials. They can also be utilized in harsh environmental conditions.

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

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

In silico toxicity and immunological interactions of components of calcium silicate-based and epoxy resin-based endodontic sealers.

The present study aimed to determine in silico toxicity predictions of test compounds from hydraulic calcium silicate-based sealers (HCSBS) and AH Plus and computationally simulate the interaction between these substances and mediators of periapical inflammation via molecular docking. All chemical information of the test compounds was obtained from the PubChem site. Predictions for bioavailability and toxicity analyses were determined by the Molinspiration Cheminformatics, pkCSM, ProTox-II and OSIRIS Property Explorer platforms. Molecular docking was performed using the Autodock4 AMDock v.1.5.2 program to analyse interactions between proteins (IL-1β, IL-6, IL-8, IL-10 and TNF-α) and ligands (calcium silicate hydrate, zirconium oxide, bisphenol-A epoxy resin, dibenzylamine, iron oxide and calcium tungstate) to establish the affinity and bonding mode between systems. Bisphenol-A epoxy resin had the lowest maximum dose tolerated in humans and was the test compound with the largest number of toxicological properties (hepatotoxicity, carcinogenicity and irritant). All systems had favourable molecular docking. However, the ligands bisphenol-A epoxy resin and dibenzylamine had the greatest affinity with the cytokines tested. In silico predictions and molecular docking pointed the higher toxicity and greater interaction with mediators of periapical inflammation of the main test compounds from AH Plus compared to those from HCSBS. This is the first in silico study involving endodontic materials and may serve as the basis for further research that can generate more data, producing knowledge on the interference of each chemical compound in the composition of different root canal sealers.

Mechanical and electrical performance of glass fiber reinforced plastic insulation for cryogenic application in fusion magnet irradiated in fast breeder reactor

In a superconducting (SC) magnet fusion reactor, the insulation material used has to withstand significant fluxes of neutrons and neutron-induced gamma radiation. Epoxy-based glass fiber-reinforced plastic (GFRP) composites are the insulation system for fusion magnets and are highly demanding. This insulation system requires excellent mechanical and electrical performance under mixed neutron and gamma radiation at cryogenic temperatures. The insulation material developed consists of boron-free S-glass fiber impregnated with a two-component modified Diglycidyl ether of Bisphenol-A (DGEBA) epoxy resin. An anhydride-cured DGEBA resin system is not suitable for cryogenic temperatures. Therefore, to overcome this thermal stress issue in cryogenic components of SC magnets, a high-toughness, flexible, aromatic amine-cured epoxy resin system was developed for the insulation system. In order to assess the radiation resistance for mechanical and electrical properties, the composite samples were irradiated in the fast breeder test reactor (FBTR) at IGCAR, Kalpakkam, India. The irradiation experiment was carried out for a neutron fluence of 1.0E+21 n/m2 and a gamma dose of 0.4 MGy at a full reactor power of 32 MWt. The tensile strength, interlaminar shear strength, and breakdown strength measurements were investigated before and after irradiation at room temperature and 77 K. The test results indicate that no significant degradation was observed in the properties of the irradiated samples up to the above-mentioned radiation doses.

Synergistic flame retardancy and electrical conductivity in di-glycidyl ether of bisphenol-A epoxy composites with polyaniline and aluminum Tri-hydroxide

This study focuses on developing and characterizing multifunctional composites based on the diglycidyl ether of bisphenol-A (DGEBA) epoxy matrix. The aim is to enhance fire resistance and electrical conductivity properties for applications in various fields. To achieve this, aluminum tri-hydroxide (ATH) was incorporated as a flame retardant (FR) agent, while polyaniline (PANI) was added to impart electrical conductivity. The composites were categorized into three groups: the first containing flame retardant (FR), the second containing PANI for conductivity, and the third containing both PANI and FR for combined effects. E 60-FP emerged as the optimal multifunctional composite, exhibiting superior mechanical properties among the tested formulations. Thermogravimetric analysis (TGA) results provided valuable insights into the thermal stability of E 60-FP, revealing that it retained 42% of its initial mass at a temperature of 600 °C. Additionally, the composite achieved a V-0 rating in the UL 94 test, confirming its excellent fire resistance. Notably, E 60-FP displayed impressive mechanical strength, with a tensile strength of 7.2 MPa and a tensile modulus of 1117.6 MPa. Its flexural strength and modulus were measured at 31.2 MPa and 2800.2 MPa, respectively. Furthermore, the composite E 60-FP exhibited remarkable electrical conductivity, measuring 6.1 × 10–6 S cm−1. These findings highlight the potential of DGEBA epoxy composites containing PANI and ATH as promising materials for applications requiring fire resistance and electrical conductivity properties.

Rational design of waterborne biobased epoxy methacrylates using citric acid and epoxy soybean oil for UV-curable coatings

Waterborne biobased UV-curable coatings (WBUCs) with environmentally friendly, renewable and energy-saving characteristics have attracted increasing attention. However, waterborne epoxy soybean oil-based UV-curable resin is mainly synthesized by introducing a polyurethane acrylate segment, which involves the use of toxic isocyanates. It is highly desirable to develop a more environmentally friendly method to prepare waterborne epoxy soybean oil-based UV-curable coatings. In this work, a “green + green + green” method was provided to synthesize three kinds of epoxy methacrylates, in which a citric acid (CA)-derived functional precursor (GC) was used to modify epoxy soybean oil (ESO), hydrogenated bisphenol epoxy resin (HBPAEP), and bisphenol epoxy resin (BPAEP) via an epoxy ester reaction. After confirmation by FT-IR and 1H NMR, it was found that the obtained epoxy methacrylates contain abundant intrinsic hydroxyls and carboxyls and extrinsic hydroxyls by the epoxy ester reaction, thus endowing these epoxy methacrylates with excellent hydrophilicity, compatibility, and stability. Meanwhile, after UV curing, the obtained WBUCs exhibited superior adhesion and thermal and mechanical properties. Moreover, the differences in these performances were systematically studied for these WBUCs with different compositions. Our “green + green + green” method provides a novel and rational potential design for WBUCs with high biobased content and excellent performance.

Synthesis And Applications of Bisphenol-A Epoxide Resins - A Review

Epoxy resin is a widely used substance for coatings, adhesives, composites, electrical components, LEDs, paintbrush manufacturing, fiber-reinforced plastic materials, and consumer product manufacturing (such as cases, kits, and snowboards). Epoxy resin is highly versatile due to its properties. One of the most commonly used types of epoxy resin is Bisphenol-A Epoxy resin, which is excellent for high-temperature applications, the adhesion of a variety of substrates, compression, bends, electrical insulation, mortar, grouts, adhesion, and high-tensile-strength applications. There are several types and applications of Bisphenol-A epoxy resin. This paper aims to review the types, synthesis, and applications of Bisphenol-A epoxy resin.

Preparation and performance of silicone-modified 3D printing photosensitive materials

Abstract Herein, the performance of silicone-modified 3D printing photosensitive resin was examined. Bisphenol-A epoxy acrylate (EA) was used as the substrate and isophorone diisocyanate, hydroxy-silicone oil, and hydroxyethyl acrylate were used as the raw materials. A silicone intermediate was synthesized to modify the substrate to prepare the 3D printing photosensitive material. The as-synthesized materials were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. The tensile fracture morphology was also analyzed. The effects of the addition of silicone intermediates on the mechanical properties, thermal stability, and shrinkage of the prepared 3D printing photosensitive resins were investigated. The results showed that an organosilicone group was successfully introduced into the side chain of EA. When the ratio of n(silicone):n(EA) is 0.3:1, the material has a high impact strength of 19.4 kJ·m−2, which is 32.8% higher than that of the pure resin; in addition, the elongation at break is 8.65% (compared to 6.56% of the pure resin). The maximum thermal weight loss temperature is 430.33°C, which is 6°C higher than that of the pure resin.

Indigenous Development of Epoxy Resin System for Cryogenic Services and Fusion Application

An epoxy resin system is used in a superconducting tokamak to insulate the conducting components, such as superconducting windings, cooling pipes, metal electrodes, and bonding and sealing of dissimilar material joints at cryogenic temperature. The main aim is to develop and fabricate the dissimilar material joints of metal and glass fiber reinforced plastic (GFRP) polymer in the form of cryogenic components for the superconducting fusion magnet. To bond and fabricate the dissimilar joints, the epoxy resin needs to have low viscosity, good adhesion, resistance to moisture, long usable life, and high toughness at low temperatures. A two-component-modified diglycidyl ether of bisphenol-A (DGEBA) epoxy resin was formulated with a modified polyamine-based hardener. To increase the toughness and minimize the induced thermal stress at low temperatures, a silane coupling agent, gamma-aminopropyltrithoxysilane, was used for its superior bonding and fast curing process. The tensile strength examination test results were found to 85 MPa, as per the International Organization for Standardization standard ISO 527-2, and an interlaminar shear strength of 12 MPa was found, as per the American Society for Testing and Materials standard ASTM D5868 at 77 K, respectively. The mechanical performance enhancements at 77 K overcome the issue of cracks and helium leaks that develop at cryogenic temperatures, as reported. The dissimilar material joints fabricated using the epoxy resin in the form of a cryo component have been validated in machine with an acceptable helium leak tightness of 1.0E-08 mbar-l/s. In this work, we report on the development, mechanical, thermal, and electrical performance tests, the testing and failures of various epoxy resins systems used, and the cryo components at 300 and 77 K.