Water-based Epoxy Research Articles

Enhancing the mechanical behaviour of concretes through polymer modification of the aggregate-cement paste interface

A critical obstacle to the design of polymer-cement composites is its relatively large contents required for a significant improvement on concrete performances, which increased materials cost and decreased compressive strength. In this study, an asphalt emulsion, waterborne epoxy resin, and waterborne epoxy resin modified asphalt emulsion were used to pretreat aggregates for improving the toughness of concrete at relatively low polymer contents. The results showed that, for the model aggregate concrete, the partial replacement of polymer-coated aggregates could induce cracks and yielded better improvement in concrete toughness as compared to full replacement. However, the three-point bending tests showed the opposite results, compared with partial replacement, complete replacement of polymer coated aggregate increases the fracture energy which can be attributed to the interlocking effect of the gravel aggregate. The addition of water-based epoxy resin-asphalt emulsion composite emulsion showed the best improvement on concrete toughness. With 30% composite emulsion coated aggregate, concrete showed almost the same strength with 33% increase in concrete fracture energy. With 100% composite emulsion coated aggregate, concrete showed about 11.5% decrease in compressive strength, but 73.4% increase in concrete fracture energy. Increasing the polymer film thickness on the aggregate surface could significantly increase the energy consumption during the fracture process of concrete and improve its toughness.

Ultraductile waterborne epoxy-concrete composite repair material: Epoxy-fiber synergistic effect on flexural and tensile performance

With the extension of service time, infrastructure is in growing urgency for repair and reinforcement due to its deterioration in safety and durability over the years. Normal cement concrete has shortcomings, e.g., high brittleness and low flexural-tensile strength, that fail to meet the requirements of construction repair. In this paper, a novel waterborne epoxy-concrete composite repair material (WECM) was prepared by using self-synthesized water-based epoxy resin based on the molecular structure-activity relationship. The mechanisms of waterborne epoxy (WEP) and WEP-fiber synergy on the improvement of concrete performance were clarified. The results show that the defects of high brittleness and poor ductility of concrete are significantly improved by WEP and that the ductility of WECM is increased by 300%–600% compared with the control concrete. The fiber and WEP in the WECM exhibited a synergistic effect on the tensile strength, ductility, and crack resistance of concrete in which the fiber coating layer mixed with WEP and embedded cement particles (inlay) provided fiber protection as well as an interfacial bonding enhancement. The P/C of 0.2 is the turning point of the flexural and tensile strength of the WECM, which is related to the continuous phase formation of the WEP-interpenetrating polymer network (WEP-IPN).

Evaluation of Surfactants on Graphene Dispersion and Thermal Performance for Heat Dissipation Coating.

With the development of thin and high-power electronic devices, heat dissipation has become an important and urgent issue in thermal management. In this study, a water-based epoxy was used as a polymer matrix to prepare heat dissipation coatings utilizing low volatile organic compounds, which were environmentally friendly and had a high heat-dissipating performance. Graphene flakes, multi-walled carbon nanotubes and aluminum oxide particles were used as fillers for preparing the heat dissipation coating. The graphene flakes and multi-walled carbon nanotubes were dispersed in a water-based epoxy by adding sodium dihexyl sulfosuccinate and poly (dimethyldiallylammonium chloride). These two surfactants were combined as a dispersant to improve the dispersibility of the carbon nanomaterials in the water-based epoxy. The synergistic effect of the well-dispersed fillers improved the heat-dissipating performance. The experimental results show that the infrared emissivity of the heat dissipation film was 0.96 after filling 30 wt% aluminum oxide particles, 2 wt% graphene flakes and 2 wt% multi-walled carbon nanotubes into a water-based epoxy. The heat dissipation film reduced the thermal equilibrium temperature of the bare copper panel by 17.8 °C under a heating power of 10 W. The film was applied in a heat dissipation test on a 15 W LED bulb, and the thermal equilibrium temperature was reduced by 21.3 °C. The results demonstrate that the carbon nanomaterial-based heat dissipation coating with a water-based epoxy could significantly reduce the thermal equilibrium temperature, giving a high potential for the application of thermal management.

Studying the Active Corrosion Inhibition Effect of the Ce3+/2-Mercaptobenzothiazole Loaded NaY Zeolite/Zn-Al LDH Based Containers in a Silane Coating

In the present study, the corrosion protective ability of the sol-gel based composite coatings containing two-different types of the cationic/anionic based inhibitors loaded containers. For this purpose, the NaY zeolite and Zn-Al Layered double hydroxides (LDHs) containers were loaded with Ce3+ cations and 2- mercaptobenzothiazole (MBT) separately. The morphology and composition of the constructed micro/nanocontainers were studied using analytical methods, confirming the successful loading of the inhibitors. In this study, the Ce3+/MBT inhibitors were successfully introduced into the LDH/NaY-based zeolite containers.Results evidenced that the combination of the two inhibitors has a constructive effect on the active protection of the AA2024-T3 sheets. SEM micrographs of the unfilled LDH and stupefaction with MBT show that the prepared LDHs have sheet-like morphology. The addition of single-inhibitor filled containers to the sol-gel hybrid coating, and water-based epoxy coating provided active protection for the AA2024-T3 coated substrate. However, the combination of the filled containers with the inhibitor in the above-mentioned coatings resulted in the improvement of the active protection of the substrate, which confirms the synergy between the particles. The NaY containers loaded with the Ce3+ resulted in a significant increase of the |Z|0.01 Hz of the gel-sol hybrid coatings, which indicates the formation of a stable oxide layer with higher resistance. Whereas the |Z|0.01 Hz of the hybrid sol-gel coatings loaded with LDH-MBT were in the same range as the NaY-Ce loaded coatings, containing NaY-Ce and LDH-MBT, showed the highest |Z|0.01 Hz values that indicate the synergy between the inorganic (Ce3+) and organic (MBT) inhibitors in sol-gel hybrid coatings.

Study on the effect of WER and EVA on the performance and microstructure of cement mortars for a prefabricated residential floor

In this study, cement mortars were modified with ethylene-co-vinyl acetate (EVA) powder and water-based epoxy resin (WER) emulsion. This study aimed to investigate the effect of the content of the two polymers on the mechanical properties, abrasion resistance, and toughness of the mortar and to relate these properties to the microstructure of the mortar. We combined IPP(a combination of Stereo Light Microscopy and Image-Pro Plus image processing software) and the mercury intrusion porosimetry (MIP) to analyze the microscopic pore structure of polymer modified mortars. The microstructure of polymer modified mortars was studied by scanning electron microscopy (SEM). The results show that the use of alternating wet and dry curing regimes helps to improve the toughness of the modified mortar. Under this curing regime, the maximum flexural strength of the polymer modified mortar was 14.32 MPa and the maximum compressive strength was 90.52 MPa. The addition of polymer significantly improved the abrasion and impact resistance of the cement mortar, with a 28% reduction in abrasion volume from 116 mm3 to 83 mm3 and a 36% increase in impact strength from 13.92 J/cm2 to 18.97 J/cm2. Both polymers have the effect of filling capillary pores in the mortar, but there is a difference in the effect on large-size pores at high dosing levels. This work contributes to an in-depth understanding of the role of polymers in improving the performance of cement mortars, which enables rational development of polymer modified cementitious materials for prefabricated residential floors.

Effect of Curing Agent Dosage on Fire Resistance of Waterborne Epoxy Coating

The water-based epoxy fire retardant coating is formed by reaction curing, which not only has good anti-corrosion performance, but also has environmental protection and flame retardant performance, which is suitable for construction machinery painting or steel structure buildings. However, the curing and cross-linking process of water-based epoxy coatings is centered on the curing agent, which gradually diffuses into the epoxy resin particles. The curing agent molecules first contact the surface of the epoxy resin dispersed phase particles and undergo a cross-linking curing reaction. As the reaction progresses, the relative molecular weight and glass transition temperature of the epoxy resin on the particle surface gradually increase, so that the diffusion rate of the curing agent molecules into the particles gradually slows down, which means that the curing reaction inside the epoxy resin dispersed phase particles Less than its surface, resulting in a low internal crosslink density, and ultimately not all epoxy groups have the opportunity to interact with the activating groups of the curing agent. Therefore, this paper studies different proportions of waterborne epoxy emulsion and curing agent. The results show that when m (epoxy emulsion): m (curing agent) = 7:3, the fire resistance and comprehensive performance of the coating are the best.

Effect of colloid solution concentration of epoxy resin on properties of rust-cracked reinforced concrete repaired by electrophoretic deposition

An electrophoretic deposition technique is proposed for repairing rust-cracked concrete. A water-based cationic epoxy resin was used as the main base material of a high-performance epoxy resin colloidal (HERC) solution, focusing on the resulting concentration of electrophoretic deposition and post-repair performance metrics. Water and carbonation resistance of repaired specimens improved significantly with increased HERC concentration. Compressive strength and splitting tensile strength also improved. A microscopic morphology analysis showed that water and carbonation resistance, and strength of repaired specimens improved because a dense resin film structure formed on the crack surface, and resin was deposited and consolidated in the cracks, respectively.

Synthesis of robust polyaniline microcapsules via UV-initiated emulsion polymerization for self-healing and anti-corrosion coating

A novel kind of robust PANI microcapsules were prepared via a one-pot photopolymerization and interfacial aniline polymerization. In our strategy, lignosulfonate was employed as emulsifier to stabilize oil-in-water emulsion, in which the oil phase was composed of self-healing agent (tung oil), photo-crosslinkable acrylic monomer and crosslinker. Under UV light, the acrylic monomer and crosslinker were photo-polymerized and formed a cross-linked polyacrylic shell, endowing sufficient robustness to the microcapsules. Aniline was subsequently added to the water phase and polymerized at the oil-water interface, which converted to a second shell and endowed anticorrosion property. FTIR, TGA and SEM tests proved the successful preparation of PANI microcapsules, and the loading of tung oil in the microcapsules reached 55.1 wt%. These microcapsules could keep integrity and be uniformly dispersed in water-based epoxy coating. The incorporation of PANI microcapsules in the coating not only imparted self-healing properties to the coatings, but also greatly enhanced its anticorrosion performance. The scratch test indicated that the coatings containing only 5 wt% microcapsules could autonomously heal a scratch with 50 μm in width. In addition, the healed coatings with the microcapsules showed almost no corrosion products after 500 h salt spray test (SST), while for the scratched neat epoxy coating, a large area of coating peeled from the substrate after only 200 h SST. The remarkably enhanced corrosion protection capability was owing to the closure of the scratch by the self-healing effect and the inhibition efficiency of PANI.

Evaluation of cerium oxide nanoparticle coating as corrosion inhibitor for mild steel

This study had dealt with the resistance to corrosion with nanostructured materials since they consume less energy and was employed in a variety of lightweight applications. For this study, nano-sized cerium oxide had been used as an anti-corrosive inhibition. This CeO2 nanoparticle was synthesized utilizing a hydrothermal technique. The coating was obtained by mixing various concentrations of CeO2 nanoparticles with a water-based epoxy resin. Resistance to corrosion with the formulated coating on a mild steel substrate was tested inside a simulated concrete pore solution containing 0.5 M NaCl solution. The corrosion inhibiting effect was evaluated by immersing the nano CeO2 – Epoxy composite coated mild steel substrate in a simulated concrete pore solution utilizing electrochemical impedance spectroscopy methodology. Tafel tests were used to calculate the corrosion rate. The outcomes showed that the nano-sized cerium oxide as filler material for epoxy covering displayed a superior corrosion inhibiting effect along with the commencement of a stable protective shield when compared to substrate of pure epoxy and without coating.

Anti-corrosion and wear-resistant coating of waterborne epoxy resin by concrete- like three-dimensional functionalized framework fillers

Waterborne protective coatings have attracted tremendous attention recently, but their practical applications are severely limited by week shielding performance and poor mechanical durability. Herein, a concrete-like three-dimensional network filler was designed by stacking fly ash, graphene oxide, and multi-walled carbon nanotubes onto each other with the help of a silane coupling agent to enhance the anti-corrosion performance and wear resistance of waterborne epoxy coating. Through chemical modification, the surface of the filler has a large number of both epoxy and amino groups, and the filler-filler, resin-filler, and resin-resin multi-dimensional cross-linking reactions occur inside the coating to improve the cross-linking performance of the water-based resin. With the help of the stable structure of the “imitation” concrete structure and greater interface strength of the silane-modified composite material, the water-based coating exhibits excellent anti-corrosion and wear resistance. The mass loss of the imitation concrete coating is only 0.0098 g per-cycle of Taber friction testing, and in the electrochemical impedance spectroscopy test, its |Z|0.01 Hz value became stabilized at approximately 1 × 107 Ω·cm2 after 14 d of being immersed in 3.5% NaCl solution, and its value was two orders of magnitude higher than that of pure epoxy. The results show the matching of the three different types of fillers in the imitation concrete, and interface chemical control of the filler surface can improve the compatibility between the functional filler and water-based epoxy resin. The use of industrial waste fly ash as one of the main fillers is conducive to promoting the recycling of resources, so that the coating has a certain cost performance and engineering application value. This study is expected to open new insights into specialized design of the internal filler of such coatings and the modification of the internal surface of a water-based coating improves the coating’s anti-corrosion and wear resistance.

The Effect of Bisphenol A Polyether Polyols on the Synthesis of Hydrophilic Epoxy Resins

The article uses three types of Bisphenol A polyether polyols BEO, BPO-6 and BPO-10 as raw materials, reacts with epichlorohydrin under the action of a catalyst and synthesizes a hydrophilic epoxy resin. The molecular structure of the product is analyzed by infrared spectroscopy and the results show that the synthesis of the hydrophilic epoxy resin BEOGE conforms to the results of the experimental design. The research results show that the hydrophilicity, epoxy value, tensile strength and elongation rate of cured product of BEOGE synthesized from BEO are better than those synthesized by BPO-6 and BPO-10 and the hydrophilic-lipophilic balance value of BEOGE is 6.531, which is between epoxy resin and water-based epoxy resin. It facilitates its adsorption at the oil-water interface and meets the synthesis requirements of hydrophilic epoxy resin. When tetra ethylene pen amine is used as the curing agent, the tensile strength and elongation at break of the cured product are tested. The results show that the tensile strength and elongation at break of the cured product of BEOGE are far better than those of BPOGE-6 and BPOGE-10. Among them, the BEOGE cured product has the highest tensile strength value of 0.59 MPa, which is 1.79 times that of BPOGE-6 and 4.92 times that of BPOGE-10. The elongation at break of the cured product of BEOGE is the largest at 9.9%, which is 1.87 times of that of BPOGE-6 and 1.46 times of that of BPOGE-10.

Research on Crack Resistance of Semi-flexible Pavement Materials

Semi-flexible pavement has been widely used in China's road construction due to its excellent rutting resistance. Due to the large difference in volume stability between the matrix asphalt mixture and the cement mortar, the internal stress of the semi-flexible pavement material is concentrated and cracking is likely to occur. To explore the influence of different Influencing factors on the cracking resistance of semi-flexible pavement materials. This paper used the orthogonal design method to design the mix ratio of ordinary cement mortar. On this basis, admixtures (silica fume, ordinary emulsified asphalt, water-based epoxy resin) were added to prepare special cement mortar. Then, using cement mortar type, matrix porosity, matrix asphalt type, matrix aggregate type as the influencing factors, this article has studied his influence on the crack resistance of semi-flexible pavement materials. Tests show that cement mortar type, matrix porosity, matrix asphalt type, matrix aggregate type have varying degrees of influence on the crack resistance of semi-flexible pavement. The effect of matrix porosity on low temperature crack resistance is the greatest, followed by asphalt and cement mortar types, and the lowest by aggregate type. Enhancing the flexibility of cement mortar and enhancing the elastoplasticity of the matrix are conducive to improving the low-temperature performance of semi-flexible pavements.

Development of the Fog Seal Layer Characterized by Durability in Terms of Skid Resistance

In this paper, based on the thermosetting properties, bonding performance, high‐temperature water damage resistance, and aging resistance properties of epoxy‐emulsified asphalt, the best formulation of epoxy emulsified asphalt as a skid resistance fog sealing asphalt is studied. Through accelerated wheel wear and other tests, the effects of the ratio of the amount of skid resistance particles to the amount of epoxy emulsified asphalt, the total amount of skid resistance fog seal asphalt, and the construction process on the skid resistance durability of the skid resistance fog seal were studied. The results show that the epoxy emulsified asphalt formula code A80 (E2) (emulsified asphalt : water‐based epoxy = 80 : 20) is the best formula; when the proportion of emery and epoxy emulsified asphalt is 1 : 1, the British Pendulum Number (BPN) reduction rate of the skid resistance fog seal‐test piece worn 100,000 times was 27.4%. Compared with the same period, the reduction rate was reduced by 4.6% on average, with the smallest mass loss rate and the best skid resistance durability. When the total amount of skid resistance fog seal asphalt is 1.2 kg/m2, the BPN reduction rate of the skid resistance fog seal specimen worn 100,000 times was 27.4%, which is an average reduction of 5.8% over the same period, and the mass loss rate is the smallest, and the skid resistance durability optimal. When using the premixed process, the BPN of the specimen was reduced by 13.2% after abrasion of 100,000 times. Compared with the “one asphalt and one sand” and “double asphalt and one sand” molded specimens, the mass loss rate was reduced by 15.0%, 4eU&7.2%, showing the best skid resistance performance. The results can provide guidance for the design and construction of AC‐13 and other pavement skid resistance fog seals.

Synthesis and Characterization of Water-Based Epoxy-Acrylate/Graphene Oxide Decorated with Fe3O4 Nanoparticles Coatings and Its Enhanced Anticorrosion Properties

ABSTRACT In this article, water-based epoxy–acrylate (EP/AC) emulsion coatings and its nanocomposites with Fe3O4 nanoparticles, graphene oxide nanosheets and graphene oxide which was decorated with Fe3O4 nanoparticles were synthesized. This was executed by means of a pre-emulsion seeded semi-batch emulsion polymerization handle with a blend of conventional anionic surfactant (Polyalkylene glycol ether sulfate, ammonium salt-EXOSEL 20 S) and typical nonionic type emulsifier (Octylphenol polyoxyethylene ether OP-10) for emulsion polymerization (schematic 1). Prepared nanoparticles were investigated with different analyzing methods like FT-IR, XRD, SEM-EDAX and TGA. The impact of the distinctive nanostructures in an (EP/AC) resin, on coated steel panels with the features of corrosion conservation, was investigated by the test of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Morphology of surface and thermal behavior of nanocomposite tests were executed using surface filtering electron microscopy (FE-SEM) and thermal gravimetric analysis (TGA). Different analyses resulted from nanostructures and nanocomposites approved very good dispersion of fillers in nanocomposite beads. Besides, they indicate the effective role of nanoparticles especially graphene oxide which was decorated with Fe3O4 nanoparticles in corrosion resistance of water-based EP/AC coatings and other properties of coated instances.

Water-based epoxy coatings with pH-sensitive TiO2 containers for active corrosion protection of carbon steel

ABSTRACT Smart containers can be produced with polyelectrolyte multilayers that can release inhibitors in response to environmental changes at the coating defects. In this study, mesoporous TiO2 hollow spheres were adopted as carriers for the encapsulation of corrosion inhibitor. The inhibitor-loaded TiO2 containers were modified by polyelectrolyte shells using layer-by-layer self-assembly technology. The release behaviour of the encapsulated inhibitor was investigated using UV–visible spectroscopy. Corrosion protection performance of the epoxy coating with polyelectrolyte-modified TiO2 containers was studied using electrochemical impedance spectroscopy and scanning Kelvin probe (SKP) techniques. Epoxy coating with the polyelectrolyte-modified TiO2 containers provided better barrier properties than that of the blank coating. Waterborne epoxy coating impregnated with the polyelectrolyte-modified TiO2 containers presented a significant self-healing effect after immersion in 0.5 M NaCl solution from the SKP results.

Synthesis and Characterization of Hydrotalcite/Graphene Oxide Containing Benzoate for Corrosion Protection of Carbon Steel

This work examined the corrosion protection performance of benzoate loaded hydrotalcite/graphene oxide (HT/GO-BZ) for carbon steel. HT/GO-BZ was fabricated by the co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, and scanning electronic microscopy. The corrosion inhibition action of HT/GO-BZ on carbon steel in 0.1 M NaCl solution was evaluated by electrochemical measurements. The benzoate content in HT/GO-BZ was determined by UV-Vis spectroscopy. Subsequently, the effect of HT/GO-BZ on the corrosion resistance of the water-based epoxy coating was investigated by the salt spray test. The obtained results demonstrated the intercalation of benzoate and GO in the hydrotalcite structure. The benzoate content in HT/GO-BZ was about 16%. The polarization curves of the carbon steel electrode revealed anodic corrosion inhibition activity of HT/GO-BZ and the inhibition efficiency was about 95.2% at a concentration of 3g/L. The GO present in HT/GO-BZ enhanced the inhibition effect of HT-BZ. The presence of HT/GO-BZ improved the corrosion resistance of the waterborne epoxy coating.

Polypyrrole Modified E-Coat Paint for Corrosion Protection of Aluminum AA1200

This article reports the potential of Polypyrrole (PPy) particles as anticorrosive additive on an epoxy water-based paint to increase the corrosion protective property of aluminum-coated panels. AA1200 aluminum panels were painted using the electrophoretic deposition method and the coatings with different concentrations of PPy particles tested. PPy particles were synthetized by oxidative polymerization of pyrrole (Py) with iron (III) chloride hexahydrate (FeCl3.6H2O) in the presence of dodecylbenzenesulfonic acid (DBSA). Electrically conducting PPy particles (6.5 S.cm-1) were obtained with a size average of 154 nm. The as-prepared PPy particles were added into a water-based epoxy paint and AA1200 panels were coated via electrophoretic deposition method. The corrosion protective properties of e-coated AA1200 panels were evaluated by means of electrochemical impedance spectroscopy over prolonged exposure time in neutral non-aerated 0.1 M NaCl electrolyte. In particular, the addition of 0.4 wt. % PPy has improved the coating corrosion protective property with respect to epoxy clearcoat and exhibited the highest value among the studied coatings.

Self-alignment of cationic graphene oxide nanosheets for anticorrosive reinforcement of epoxy coatings

Designing coatings with long term anticorrosion performance remains a great challenge. Herein, a newfangled cationic dopamine-reduced graphene oxide (DRGO+) nanosheet is prepared as a filler for epoxy coating via simple dopamine oxidative self-polymerization and ionization reaction. DRGO+ can be dispersed stably in commercial water-based cathodic epoxy emulsion for more than 45 days without precipitation. Due to the presence of –NH3+ in DRGO+, it can be self-aligned parallel arrangement in the composite coating (DRGO+/EP coating) under the electric field. This highly parallel DRGO+ nanosheets tremendously improve the physical barrier effect of the coating and prolong the penetration path of the corrosive medium. Electrochemical impedance spectroscopy (EIS) test showed that the initial low-frequency impedance modulus of 0.5%-DRGO+/EP coating is as high as 4.79 × 1010 Ω cm2 when the content of DRGO+ is 0.5 wt%, which is an order of magnitude higher than that of pure epoxy coating (4.07 × 109 Ω cm2), exhibiting extraordinary corrosion resistance. Finally, the protective mechanism of composite coating is revealed by the identification of corrosion products and local-EIS techniques. In view of the validity of DRGO+, this work highlights the potential route for the large-scale preparation of coatings with superior long-term anti-corrosion.

Preparation of water-based epoxy resin and its application as an automotive air filter paper binder

Water-based epoxy resin emulsion was prepared by emulsifying o-cresol formaldehyde epoxy resin with self-emulsified epoxy curing agent synthesized in this study and then used as an environmentally friendly binder for automotive air filter paper. The preparation process of the self-emulsified epoxy curing agent was confirmed by Fourier transform infrared spectroscopy (FTIR). The effects of neutralization degree (Neu) and amount of curing agent on the formation of epoxy resin emulsion were studied. The micro-morphology and size distribution of the epoxy resin latex were characterized by transmission electron microscopy (TEM) and dynamic and static light scattering, respectively. The micro-structure of the air filter paper surface was studied by scanning electron microscope (SEM). The mechanical strength and moisture-resistance properties of air filter strengthened by the prepared water-based epoxy resin emulsion was tested and compared to three commercial binders. The prepared epoxy resin emulsion greatly enhanced the mechanical properties and moisture-resistance properties of the air filter paper while maintaining its filtration properties. Therefore, the epoxy resin emulsion can be used as an environmentally friendly water-based binder for automotive air filter paper with excellent comprehensive properties.

Rheological characterization of the curing process for a water-based epoxy added with polythiol crosslinking agent

Rheological characterization of the curing process for a water-based epoxy added with polythiol crosslinking agent