Epoxy Content Research Articles

Investigation and Evaluation of the Emulsified Asphalt with Waterborne Epoxy Resin

Compared with SBR latex, waterborne epoxy resin has obvious advantages. The cured epoxy resin emulsified asphalt material has stronger mechanical properties, but it is less used in asphalt modification applications. Aiming at this problem, this paper uses waterborne epoxy resin as the modified material of emulsified asphalt, and carries out performance characterization and road performance evaluation of waterborne epoxy resin modified emulsified asphalt and its mixture under different dosages. Fluorescence microscopic analysis of waterborne epoxy asphalt with a content of 8wt%, 15wt%, 30wt%, and 50wt%, respectively, shows that the resin content should not exceed 30wt% to ensure the performance of asphalt. The bonding properties of SBR modified emulsified asphalt and waterborne epoxy resin modified emulsified asphalt with different dosages at 20 °C and 60 °C were analyzed. The results show that the tensile strength and oblique shear of waterborne epoxy modified emulsified asphalt. The strength is higher than SBR modified emulsified asphalt, and its high temperature resistance is better than SBR modified emulsified asphalt material. The road performance analysis was carried out on the mixture prepared by the aqueous epoxy modified emulsified asphalt with the content of 0wt%, 8wt%, 15wt% and 30wt% respectively. The results show that with the increase of waterborne epoxy content, the Marshall stability, splitting strength and high temperature rutting resistance of the mixture increase more obviously. The freeze-thaw splitting strength of the waterborne epoxy resin mixture is 13% higher than that of the pure emulsified asphalt mixture, and the splitting strength is also significantly improved. Due to the high stiffness of the waterborne epoxy resin after curing, the maximum bending strain of the mixture is reduced, and the recommended dosage is not more than 30% by weight. On the whole, the introduction of waterborne epoxy resin could greatly improve the strength and road performance of the asphalt, and could be used as a proper road repair material.

Electrochemical Investigation of Corrosion Behavior of Epoxy Modified Silicate Zinc-Rich Coatings in 3.5% NaCl Solution

In order to develop waterborne silicate anticorrosive coatings to replace solvent-based anticorrosive coatings used widely in the shipping industry, epoxy modified silicate emulsions were synthesized with different contents of epoxy resin, then aqueous silicate zinc-rich coatings were prepared with the synthesized silicate emulsion, triethylamine, and zinc powder. The influence of the content of epoxy on the properties and chemical structure of the modified emulsion, mechanical properties of the silicate coatings, and corrosion behavior of the silicate zinc-rich coatings in 3.5% NaCl solution were investigated. The coating samples on steel were measured by the immersion test, Tafel polarization test, and electrochemical impedance spectroscopy (EIS) test with different immersion times. The results showed that epoxy modified silicate emulsions were successfully synthesized. With the increase in epoxy content, the viscosity and solid content of the modified emulsion increased, the impact resistance of the silicate coating rose, the pencil hardness decreased, but the adhesion was not affected. Epoxy modification can reduce, to a certain extent, the corrosion driving force of the zinc rich coating and increase the impedance of the zinc-rich coating, which decreases with the increase of immersion time in 3.5% NaCl solution. With the increase in the epoxy content, the impedance value of the zinc-rich coating increases, indicating that the ability of the coating to resist corrosive media is enhanced.

Effects of phase-inversion waterborne epoxy resin on properties of cold patch waterborne epoxy emulsified asphalt

In order to evaluate effects of waterborne epoxy resin prepared by the phase-inversion method (phase-inversion waterborne epoxy resin) on properties of waterborne epoxy emulsified asphalt for cold patch engineering of asphalt pavement, a series of methods for evaluating properties of emulsified asphalt and casting resin were used. Results show that, with an increase in waterborne epoxy resin content, penetration, ductility, surface curing time of waterborne epoxy emulsified asphalt decrease and its adhesion degree, shear strength and bond strength increase. Moreover, its penetration, ductility and adhesion degree remain unchanged when the content of waterborne epoxy resin exceeds 20%, and its shear strength and bond strength increase most remarkably when the content of waterborne epoxy resin increases from 10% to 20%. The test results are explained by the surface fluorescent micromorphology of cured waterborne epoxy emulsified asphalt that, with the increase in waterborne epoxy resin content, epoxy resin particles firstly appear as segregated spots, and then change from spotted status to clustered status, and the epoxy resin phase gradually becomes a continuous phase. In conclusion, phase-inversion waterborne epoxy resin has effects on properties of the cold patch waterborne epoxy emulsified asphalt, and recommended content of waterborne epoxy resin is 20%.

Influence of TAS on photocrosslinking of the coatings on the base of acrylate, epoxide oligomers and monomers

AbstractThe influences of the triarylsulfonium hexafluoroantimonate salts (TAS) content in the range from 1 to 9 % of the total resin and monomer weight on photocrosslinking and properties of UV‐cured coatings based on epoxy diacrylate (EDA), hexanediol diacrylate (HDDA), epoxy resin modified by castor oil (CE) and 3,4‐epoxycyclohexyl‐methyl 3,4‐epoxycyclohexane carboxylate, a biscycloaliphatic diepoxide (BCDE), have been studied. It was shown that under UV‐exposure, photoinitiated radical polymerization of acrylate groups of EDA, HDDA and cationic polymerization of epoxy groups of CE, BCDE occurred very fast, leading to formation of interpenetrating polymer networks. The relationship between TAS content and polymerization of epoxy, acrylate groups as well as performance of UV‐cured coatings had optimal particularity with highest conversion rate of the groups and properties of the cured coatings containing 5 and 7 % of TAS.

Influence Mechanism of Epoxy Resin and Curing Agent on High-Temperature Performance of Asphalt

To deeply show the internal reasons for the effects of epoxy resin and curing agent on the high-temperature performance of asphalt, nine kinds of asphalt with different content of epoxy resin and curing agent were prepared. On the premise of ensuring that the softening point, penetration and ductility of epoxy asphalt no attenuation, the dynamic shear rheology test and Saybolt viscosity test were used to examine the rutting factor (G*/sin δ), complex shear modulus (G*), phase angle (δ), and viscosity of asphalt with different epoxy resin and curing agent contents. With the help of fluorescence microscopy, microscopic morphology was analyzed, and the micro-image was further analyzed quantitatively by using 3Dsurface and particle statistics. The results show that adding epoxy resin and curing agent into asphalt can significantly improve the rutting factor and complex shear modulus of asphalt and reduce the phase angle and the viscosity growth rate of asphalt changed from fast to slow. Fluorescence and 3Dsurface imaging results indicate when the epoxy resin and the curing agent are uniformly distributed and forms microflocculent structures, the epoxy resin can fully swell in asphalt, and the fluorescence intensity is uniform. The statistical analysis of particles shows that the improvement in high-temperature performance of asphalt by epoxy resin and curing agent results from the distribution of particle area above 26.7346 μm2. The high-temperature performance of epoxy asphalt is optimal when the content of epoxy resin and curing agent is 6 %.

Study of imidazole performance as pseudo-affinity ligand in the purification of IgG from bovine milk

The spherical sepharose CL-6B beads were activated by epichlorohydrin in different epoxy contents (80, 120 and 160 μmolepoxide/mLgel) and, l-histidine and imidazole as pseudo-affinity ligands were covalently immobilized to them. Some linkers with different length, (1,2-ethanediol diglycidyl ether and 1,4-butanediol diglycidyl ether) were synthesized for activation of sepharose and the activated sepharose beads modified with imidazole and the performance of these adsorbents in the purification of immunoglobulin G from bovine milk were evaluated. Among the l-histidine bearing adsorbents, higher adsorption of IgG (0.28 mg/mL) was obtained by adsorbent with the lower concentration of l-histidine. The highest amount of IgG adsorption (0.53 mg/mL) was obtained by imidazole bearing adsorbent with the highest amount of imidazole and Among the adsorbents with synthesized linkers, the adsorbent with 1,2-ethanediol diglycidyl ether showed better performance and was able to purify 0.25 mg/mL IgG with high purity. The synthesized pseudo-affinity adsorbents represented the abbility to purify immunoglobulin G in one-step process with high purity and efficiency.

Silica-Filled Composites from Epoxidized Natural Oils

Thermosetting cast resins, filled with varying levels of silica, were prepared from epoxidized soybean oil (ESO) and epoxidized triolein (ETO) in order to study matrix-filler interactions and effects of cross-linking density on physical properties. While ESO is characterized by a highly heterogeneous composition, ETO had very regular structure but lower epoxy content. Room temperature ring opening polymerization initiated with butanediol was catalyzed by fluoroboric acid. Epoxy matrices were almost entirely made from natural oils, with cross-link densities correlated with epoxy oxygen content in the epoxidized oils. In spite of high cross-link density, glass transitions of ESO and ETO matrices were below room temperature, which was attributed partially to the plasticizing effect of “dangling chains” and side reactions (cyclization). Ground silica particles increased strength and modulus but did not shift glass transition in a predictable way. The impact of filler on mechanical properties was more pronounced in composites prepared with lower functionality ETO. These rapidly setting materials were prepared by a simple process of mixing and casting. The resulting inexpensive epoxy composites displayed relatively low polarity and low dielectric loss, particularly in the glassy state, and therefore may show utility in electrical insulation applications.

Influence of Epoxy Content on the Properties and Marine Bacterial Adhesion of Epoxy Modified Silicone Coatings

This study addresses the issue of enhancing the mechanical properties and adhesion of silicone antifouling coatings. In this paper, γ-aminopropyltriethoxysilane was used to pretreat bisphenol A epoxy resin to obtain epoxy-silicone prepolymer, which was then mixed with hydroxyl-terminated polydimethylsiloxane to obtain epoxy-modified silicone. It was cured with polyamide curing agent and dibutyltin dilaurate catalyst to form film, and a three-component epoxy-modified silicone coating was prepared. Fourier transform infrared (FTIR) spectroscopy was used to characterize its chemical structure. The effects of epoxy content on the surface properties, mechanical properties and antibacterial properties of the coatings were characterized by confocal laser scanning microscope (CLSM), contact angle measurements, tensile test and bacterial adhesion test. The results show that adding epoxy makes the adhesion of the coating at level 1 and the surface free energy of the coating was between 15–21 mJ/m2. When its content is less than 22.1 wt %, the coating is in a ductile material state. Once it is higher than 22.1 wt %, the coating was in a brittle material state. As the content increases, material’s hardness and fracture strength increases; elastic modulus decreases first and then increases, but bacteria removal rate decreases. The modification of the epoxy to silicone can effectively improve the adhesion and mechanical properties of the coating, while maintaining the characteristics of the low surface of the coating. It plays a positive role in improving the performance of silicone antifouling coatings.

Improvement in phase-change hybrid nanocomposites material based on polyethylene glycol/epoxy/graphene for thermal protection systems

Polyethylene glycol (PEG) is established as an organic solid–liquid phase-change material (PCM) offering a wide range of enthalpies and phase transition temperatures as a function of its molecular weight. PCMs are known for their high-energy absorbance; however, they also have two main drawbacks of leakage and enthalpy reduction during melting. In this work, polyethylene glycol as a phase-change material and graphene oxide (GO), expanded graphene (EG), and epoxy resin (EP) as shape stabilizing materials were used and designed based on experimental design—Taguchi method to find the composition with the least molten PEG leakage and the highest enthalpy of melting. Based on improvements made on main drawbacks, two samples were introduced, while their only difference was epoxy content. The results showed that the epoxy resin and graphene oxide caused a significant reduction in molten PEG leakage by hydrogen bonding and trapping of PEG between GO plates and the barrier effect. Also, the expanded graphene by heterogeneous nucleation of molten PEG in a cooling cycle caused a dramatic increment in crystallinity and enthalpy of melting. Among the achievements of this research is the attainment of hybrid nanocomposites samples without leakage (less than 5 wt%) and samples with enthalpy of melting more than that of pure polyethylene glycol (8%).

Sustainable access to fully biobased epoxidized vegetable oil thermoset materials prepared by thermal or UV-cationic processes.

Beyond the need to find a non-toxic alternative to DiGlycidyl Ether of Bisphenol-A (DGEBA), the serious subject of non-epichlorohydrin epoxy resins production remains a crucial challenge that must be solved for the next epoxy resin generations. In this context, this study focuses on the valorization of vegetable oils (VOs) into thermoset materials by using (i) epoxidation of the VOs through the “double bonds to epoxy” synthetic route and (ii) synthesis of crosslinked homopolymers by UV or hardener-free thermal curing processes. A thorough identification, selection and physico-chemical characterization of non-edible or non-valuated natural vegetable oils were performed. Selected VOs, characterized by a large range of double bond contents, were then chemically modified into epoxides thanks to an optimized, robust and sustainable method based on the use of acetic acid, hydrogen peroxide and Amberlite® IR-120 at 55 °C in toluene or cyclopentyl methyl ether (CMPE) as a non-hazardous and green alternative solvent. The developed environmentally friendly epoxidation process allows reaching almost complete double bond conversion with an epoxy selectivity above 94% for the 12 studied VOs. Finally, obtained epoxidized vegetable oils (EVOs), characterized by an epoxy index from 2.77 to 6.77 meq. g−1 were cured using either UV or hardener-free thermal curing. Both methods enable the synthesis of 100% biobased EVO thermoset materials whose thermomechanical performances were proved to linearly increase with the EVOs' epoxy content. This paper highlights that tunable thermomechanical performances (Tα from −19 to 50 °C and Tg from −34 to 36 °C) of EVO based thermoset materials can be reached by well selecting the starting VO raw materials.

A green approach toward epoxy-benzoxazine copolymers with shape-memory ability

In the frame of green-based chemistry, advanced shape memory polymers are designed from benzoxazine (RSBOX) and epoxy (R-EP) resins basing on potential natural raw materials, such as resorcinol and stearylamine. Thermal curing, investigated by differential scanning calorimetry, shows several overlapping peaks suggesting a complex curing mechanism. Dynamic mechanical analysis of cured RS-BOX/R-EP copolymers demonstrates an increase in the glass temperature and narrower glass transition by the increase of the RS-BOX ratio. In contrast, crosslinking density increases with higher epoxy resin content. All investigated materials possess one-way dual shape memory ability triggered by glass transition temperature with excellent shape fixity, while the shape recovery values ranged between 95 and 100%. The duration of the recovery process is significantly influenced by the RS-BOX amount. Additionally, the mechanical and shape memory properties of fully bio-based SMPs might be suitably tailored for advanced applications by merely varying the initial composition.

Durability of epoxy polymer and ordinary cement concrete in aggressive environments

Polymer concrete is well-known for quick repairing of concrete structures and pavement. However, there are relatively few studies on the durability of epoxy polymer concrete (EPC). This study aims to investigate the long-term environmental effects on the mechanical properties of EPC. Therefore, EPC and ordinary cement concrete (OCC) specimens were prepared and exposed to four chemical solutions with pH values of 2.5, 7, 12.5 and artificial seawater in intervals of 1, 3, 6, 9 and 12 months. Epoxy resin (10 and 12% by weight) and Portland cement were used as binder phase in EPC and OCC specimens, respectively. Scanning electron microscopy (SEM) was additionally applied to investigate the changes in the microstructure of specimens over a year of exposure. According to the results, the acidic solution was the most destructive environment for cement and polymer concrete which significantly decreased the compressive strength of OCC and low epoxy resin content EPC by 38.7% and 40.1%, respectively. The alkaline solution had almost the same effect as the acidic solution on OCC specimens. However, EPC performed relatively well under alkaline condition after one year of exposure. Freshwater and seawater solutions also decreased the strength of EPC. However, freshwater improved the strength of OCC specimens by 18.26% after twelve months. The seawater improved the strength of OCC up to the first six months and then the strength of OCC specimens decreased. EPC with the high content of epoxy resin had the lowest strength reduction and appropriate performance and durability in each solution among the other specimens. Further, the Taguchi method and ANOVA were used to determine the contribution of each factor based on the compressive and the splitting tensile strengths under varying concrete type, pH of solution and exposure time.

Design and synthesis of phenyl silicone rubber with functional epoxy groups through anionic copolymerization and subsequent epoxidation

In this paper, we have developed epoxidized phenyl silicone rubber (EMVPQ) with good oil and radiation resistance by anionic ring-opening copolymerization and further epoxidation modification. Silicone rubbers with both phenyl and epoxy groups were firstly synthesized and main properties of the material were characterized. When the phenyl content in EMVPQ was increased from 5% to 20%, the damping loss peak shifted to the high temperature by 36 °C and the effective damping temperature range was widened by 3 °C. The tensile strength of EMVPQ with 20% phenyl content did not change before and after irradiation. When the epoxy content is only 13%, the EMVPQ retained mechanical properties after immersion at 25 °C or 100 °C for 72 h, but a commercial sample substantially lost its mechanical properties. This work not only promotes the research of epoxidized phenyl silicone rubber, but also opens an effective way for the preparation of high-performance aerospace materials.

Green synthesis and properties of an epoxy-modified oxidized starch-grafted styrene-acrylate emulsion

An epoxy-modified oxidized starch-grafted styrene-acrylate (E-g-OS-P (BA-St)) emulsion was synthesized via soap-free core-shell emulsion polymerization without adding any solvent that could cause environmental problems. The emulsion exhibited excellent stability, chemical properties and mechanical performance. The synthesized emulsion was characterized by Fourier transform infrared spectroscopy (FTIR) and 13C NMR spectroscopy. Transmission electron microscopy (TEM) suggested that the OS-P (BA-St) latexes had certain umbrella structures and that the epoxy resin cross-linked a plurality of umbrella structures. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the thermal stability and glass transition temperature (Tg) of the polymer became higher as the content of epoxy resin increased. Atomic force microscopy (AFM) was utilized to characterize the surface morphology of the films. The film with 10% epoxy resin (based on the mass of monomers) possessed superior tensile strength and elongation, exhibiting a nearly 100% increase in tensile strength relative to that of neat latexes without epoxy. Additionally, the mechanism of polymerization and film formation of the E-g-OS-P (BA-St) emulsion were analysed.

Waterborne Epoxy Resin–Polyurethane–Emulsified Asphalt: Preparation and Properties

To obtain a waterproof binding material for bridge decks with properties of high bonding strength at high temperatures and high flexibility at low temperatures, a waterborne epoxy resin–polyurethane–emulsified asphalt (WEPEA) was prepared which can be constructed in a cold state and cured rapidly at room temperature. The composition of WEPEA was determined based on the tensile strength and elongation at breaking. The road performance of WEPEA was systematically investigated based on its high-temperature bonding properties, low-temperature flexibility, adhesion, waterproofing performance, and aging resistance. In addition, the performance of WEPEA was compared with that of SBS-modified asphalt and rubber asphalt. The viscosity variation and micromorphology of WEPEA were investigated, and the compatibility and stability of each component were verified. The results show that waterborne polyurethane can effectively improve the flexibility of emulsified asphalt with a high content of waterborne epoxy resin. WEPEA exhibited excellent bonding strength, crack resistance and anti-impact properties, adhesion to aggregates, and water stability. These properties of WEPEA were all superior to those of the SBS-modified asphalt and rubber asphalt.

Effect of epoxy content in Ag nanoparticle paste on the bonding strength of MLCC packages

Ag particles have been attractive candidates for highly reliable interconnections in electronic packages due to an absence of IMCs, high melting temperature, and high electrical and thermal conductivity. We fabricated various Ag-nanoparticle (NP) pastes containing different epoxy/binder percent weight (epoxy: 4.5, 9.0, 13.5, and 18 wt%) to investigate the effect on the bonding strength and electrical performance of multilayer ceramic capacitor (MLCC) components. MLCC joints were obtained by stencil printing Ag NP pastes on an Al2O3 substrate with Cu electrodes followed by pressureless bonding at 250 °C for 15 min. When using Ag NP pastes containing higher epoxy compositions, more residues were identified while the other organic additives, such as the binder and dispersant, were removed by debinding during the bonding process. The Ag NP-18 wt% epoxy paste showed bonding strength approximately 8.6 times that of the paste containing 4.5 wt% epoxy. However, the electrical resistivity of MLCC components of 18 wt% epoxy paste showed an electrical resistance of 3.5 Ω, which was about 1.8 times that with the 4.5 wt% epoxy paste. We designed Ag NP pastes with varying epoxy ratio, and studied their chemical, bonding, and electrical characteristics for the development of advanced interconnection.

Epoxy Resin’s Influence in Metakaolin-Based Geopolymer’s Antiseawater Corrosion Performance

To obtain the influence mechanism of epoxy resin content, curing time, and other external factors on the compressive strength and seawater corrosion resistance of geopolymer, the NaOH and Na2SiO3 were used as activators; the effect of epoxy resin concentration on the corrosion resistance of metakaolin-based geopolymer was investigated by experiments. The mechanism of epoxy resin concentration affecting the polymerization process and the properties of geopolymer was analyzed by X-ray diffraction, scanning electron microscopy-energy spectrum, and Fourier transform infrared spectroscopy. It was shown that the epoxy resin slowed down the polymerization. The presence of epoxy resin had a beneficial effect on compact structure. Furthermore, compared with the noncorrosive specimen, mixed with 30% specimen’s average compressive strength increased by 4.77MPa and 4.24MPa after curing for 1d and 3d and soaking for 56d.

Design and development of self-healing coating based on thiol–epoxy reactions

Cracks caused by the effects of mechanical or chemicals forces on coatings may cause their performance to deteriorate and may shorten their lifetime. The microcapsules used for self-healing coatings provide automatic recovery and extend the life of the coatings. In this study, polyurea-formaldehyde epoxy resin (PUF-epoxy) microcapsules were synthesized by in-situ polymerization; because, they allow the size control of the microcapsules, the thickness of the shell can be controlled, its production is easy, it is cheap and combinable with industry. Synthesized microcapsules were characterized by Fourier Transform Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), optical microscope, UV spectrum, zeta analyzer and contact angle measurements. As a result of the thermal analysis, the core (epoxy) content of the microcapsules was 57% by weight and 60% by the extraction method based on the principle of selective dissolution, and these two values were compatible with each other. The average microcapsule diameter was found as 185 nm. For the first time in the literature, an epoxy-containing microcapsule was added to the thiol-containing coating material and a self-healing coating was prepared. The epoxy-containing microcapsules were artificially cracked and the epoxy resin released from it reacted with the thiol received in the coating. For this reason, it was observed that the artificial scratches formed on the coatings showed good self-healing properties.

Nanocomposites from Clay, Cellulose Nanofibrils, and Epoxy with Improved Moisture Stability for Coatings and Semistructural Applications

A new type of high reinforcement content clay–cellulose–thermoset nanocomposite is proposed, where epoxy precursors diffuse into a wet porous clay–nanocellulose mat, followed by curing. The processing concept was scaled to >200 μm thickness composites, the mechanical properties were high for nanocomposites, and the materials showed better tensile properties at 90% RH compared with typical nanocellulose materials. The nanostructure and phase distributions were studied using transmission electron microscopy; Young’s modulus, yield strength, ultimate strength, and ductility were determined as well as moisture sorption, fire retardancy, and oxygen barrier properties. Clay and cellulose contents were varied as well as the epoxy content. Epoxy had favorable effects on moisture stability and also improved reinforcement effects at low reinforcement content. A more homogeneous nano- and mesoscale epoxy distribution is still required for further property improvements. The materials constitute a new type of three-ph...

Fabrication of Bacterial Cellulose/Polyaniline Nanocomposite Paper with Excellent Conductivity, Strength, and Flexibility

Bacterial cellulose/polyaniline (BC/PANI) nanocomposites display many potential applications in various fields. However, the conductivity and mechanical properties remain a challenge. Here, we developed a novel method to prepare BC/PANI nanocomposites via the chemical grafting of PANI onto epoxy modified BC (EBC), followed by the grafting of polyacrylamide (PAM). For comparison, an in situ BC/PANI sample was also prepared. The grafting reaction between PANI and EBC and the retention of PANI on EBC were confirmed by FTIR, X-ray photoelectron spectroscopy, and elemental analysis. The cross-section morphology of BC transformed into a three-dimensional and continuous network structure with the incorporation of PANI. The effects of epoxy and PAM contents on the morphology, conductivity, and mechanical properties of PANI-g-EBC and PANI-g-EBC3/PAM nanocomposites were investigated. Compared with those of the in situ BC/PANI sample, the conductivity of PANI-g-EBC increased from 0.12 to 1.08 S/cm, while the stress ...