Epoxy Emulsion Research Articles

The Mechanical Properties of Polypropylene Fiber Reinforced Polymer Modified Cement Mortar

Combining the effect of polypropylene fibers, such as the decrease of cement base material shrinkage and plastic crack, and the increase of material toughness, with the improvement of polymer on the interface between the fiber and matrix, both polypropylene fibers and polymer modifier were used in the cement mortar at the same time to make more excellent cement mortar materials. The improvement for cement mortar from different length of polypropylene fiber, polymer modifier (waterborne epoxy emulsion), mineral powder and silica ash were studied. Results showed that compared with the short fiber, the long fiber has a more obvious effect on the toughness, the best dosage of which is 0.6 kg/m3; the waterborne epoxy emulsion improved the bonding properties of interface between polypropylene fiber and cement mortar matrix, and then, long fibers improved flexural strength of cement mortar greatly, in terms of short fiber, effect is not manifest; With the increase of mineral powder, all the mechanical index of polypropylene fiber reinforced polymer modified cement mortar were improved and the effect of silica ash was better than that of mineral powder, the optimal replacement ratio were 0.1 and 0.3 respectively.

Study on the Synthesis and Properties of Waterborne Epoxy Resin and Curing Agent

With chemical modification method, the epoxy resin E44 was modified into water-borne epoxy resin by diethanolamine, considering the compatibility of curing agent and resin, diethylenetriamine was modified into epoxy amine curing agent as well, through single factor method to discuss the effects of reactant ratio, reaction temperature on the results of the product, the structure of the product was analyzed by Infrared spectrum. The experimental results showed that, when molar ratio of epoxy resin and diethanolamine was 4:3, reaction temperature of 70-80°C, the preparation of waterborne epoxy resin emulsion has small particle size and good stability. At the same time, when molar ratio of epoxy resin and diethylenetriamine was 1:1, reaction temperature of 80°C, the performance of waterborne epoxy curing agent is well.

Polymer Emulsion Modified Aramid Fibers Reinforced Cementitious Composites

The influence of two kinds of polymer emulsions on the flexure strength of armid fibers reinforced cementitious composites has been investigated. The morphology of fractural interface of modified composites is conducted by scanning electron microscopy (SEM). Our experiment results indicated that the early flexural strengths of the epoxy emulsion and EVA emulsion modified aramid fiber reinforced cementitious composites have been improved significantly in comparison with that of unmodified composites, that is, an increase of 34.21%, 133% observed versus pristine samples curried for 28 d, respectively. The microscopic analysis on the interface between fibers, cement and aggregates revealed a novel rupturing and stripping mechanism. The efficacy of EVA emulsion modified samples is higher than that of epoxy modified ones.

Preparation of Waterborne Epoxy Resin Emulsion

The hydrophilic carboxylic group was induced into the main chain of the bisphenol-A-type epoxy resin via alcoholysis reaction between the maleic anhydride and he secondary hydroxyl group of the bisphenol-A-type epoxy resin. Then a self-emulsifying type aqueous epoxy resin was developed. The chemical structure of the resultant was analyzed by FT-IR. The effects of temperature, time, ratio of reactants and neutralization temperature on the reaction were discussed. Then the optimum reaction condition was determined through orthogonal experiment design. The synthesized waterborne epoxy resin has favorable stability and water-dispersion.

Effect of Polymer Modified Cement-Based Coatings on Steel Bars Anticorrosion and Bond Properties between Coated Bars and Concrete

In this paper the anticorrosion properties of steel bars coated with polymer modified cement-based coatings in chloride solution were evaluated. Then the pullout tests were conducted using coated and uncoated steel bars embedded in concrete specimens and the bond properties between concrete and bars were tested. The results show the steel bars coated with epoxy emulsion modified cement-based coating (HY) and elastic copolymer emulsion modified cement-based coating (GT) have satisfactory anticorrosion properties in 3.5% NaCl solution for 96h. But the pullout tests display that the bond strength between the concrete and the steel bars coated with GT coating is much lower than that of the bars coated with HY coating and the uncoated specimens. The bond stress between the concrete and the bars coated with pure acrylate emulsion modified cement-based (CB) coating is the highest among the three coatings, but the resistance to chloride permeability of CB coating is poor. The results indicate the special epoxy-cement-based coating (HY) is more suitable for applying to the anticorrosion coating for steel bars in chloride condition.

Two-component adhesive based on aqueous emulsion of ED-20 resin for carbon-fiber reinforcement of bearing concrete structures

Use of two-component adhesive based on an aqueous emulsion of ED-20 epoxy resin modified by alkoxysilane and ultrafine particles of diamond UDA-VK, and also of a crosslinking agent Epilink 701 for carbon fiber reinforcement in the system with a carbon fabric of URAL-LO brand of bearing concrete structures was demonstrated. Physical and mechanical properties of an adhesive composition are improved in the case of the joint presence of alkoxysilane and nanoparticles of diamond in it.

Opaque paints based on a water emulsion of ÉD-20 resin for decorating glass articles

It is shown that water epoxy emulsions can be used as a binder to obtain paints for decorating glass articles. The physical-chemical properties of epoxy coatings are studied.

Synthesis and Properties of Flame-Retardant Waterborne Emulsion Derived from O-Cresol Formaldehyde Epoxy Resin

By modifying O-cresol Formaldehyde epoxy resin with DOPO and Diethanolamine, and then neutralized by acetic acid, phosphorous-containing epoxy emulsion with excellent flame retardancy can be obtained under strong agitation. Diethanolamine opening rate and neutralized degree to the formation of epoxy emulsion were optimized. The flame-retardant property of the cured phosphorous-containing epoxy resin was test by UL-94, LOI and TGA method. The result shows that when the opening rate of Diethanolamine is 25.0% and the neutralized degree is 95.0%, stable epoxy emulsion can be obtained. When phosphorus content of the epoxy resin was 3.0wt%, the LOI value of the resin can be reach to 39.2 and pass the UL-94 test，the 700°C char remaining is 30.0wt%. The result shows that the flame retardant mechanism of the phosphorous-containing epoxy resin is mainly through a condensed- phase mechanism.

Effect of Epoxy Emulsion on the Mechanical Properties and Permeability of Cement Mortar

The effects of epoxy emulsion on the mechanical properties and water and chloride permeability of cement mortar and concrete were experimentally studied. The results show that adding epoxy emulsion will improve the flexural and tensile strengths at both early (7 d) and later (28 d) ages, and the 28 d compressive strength of cement mortar, though the compressive strength at 7d will be decreased a little. The suitable dosage of epoxy emulsion is 6~10% (solid content) based on the mass of the cement in mortar. The water and chloride permeability of cement mortar are also remarkable improved when 6~10%epoxy emulsion is added.

Preparation of Waterborne Epoxy Resin Emulsion

Waterborne epoxy resin was prepared through introducing hydroxyl and carboxyl groups in the main chain of epoxy resin with the bisphenol epoxy resin, toluene diisocyanate and 2,2-dimethylol propionic acid by self-emulsification. Analyzed the structure of products via Fourier transform infrared spectrometer, then to test the water-soluble and stability. And the best conditions of reaction were determined through studying the influence of material ratio, reaction time and reaction temperature to products. The result shows that the synthesized waterborne epoxy resin has favorable stability and water-dispersion.

Effect of adsorption of nonionic surfactants on the stabilizing ability of latexes in preparation of epoxy emulsions

The effect exerted by adsorption of nonionic surfactants on the stabilizing ability of latexes in preparation of epoxy emulsions and on the structural-rheological properties of these emulsions was examined. The stabilizing effect was attributed to heterostabilization of particles of the mixed dispersed phase and to the strength of the structural framework formed.

Aqueous tape casting of boron carbide ceramic

An environmental friendly aqueous tape casting process has been introduced to fabricate B4C green tapes. Tetramethylammonium hydroxide (TMAH) and a mixture of waterborne epoxy emulsions and anionic aliphatic urethanes emulsions were selected as the dispersant and binder, respectively. The influence of pH value on the zeta potential of ceramic suspensions has been investigated, and the dispersant content added has been optimized based on the rheological behaviors of B4C slurries. The green sheets showed homogeneous microstructure with high flexibility and enough strength for the subsequent cutting and lamination. After sintering at 2100°C, dense B4C ceramics can be achieved. The relative density and the flexural strength of the sintered samples were 96.8% and 636±70MPa, respectively.

Sticky superhydrophobic filter paper developed by dip-coating of fluorinated waterborne epoxy emulsion

A superhydrophobic and superoleophilic coating for oil filter paper was synthesized based on waterborne bisphenol-A novolac epoxy emulsion. The benzoic acid (BA) and maleic anhydride (MA) were used as modification agents to give the epoxy resin hydrophilic groups (carboxyl) and CC double bonds. And the fluorinated waterborne epoxy emulsion was prepared by free radical solution polymerization of dodecafluoroheptyl methacrylate (DFMA) monomer. The covalent bound low free energy fluorinated chains in the monomer reduce the surface energy of solidification polymers sufficiently to give rise to superhydrophobic behavior while conserving superoleophilicity. Surfaces prepared show a sticky property, which exhibits a static water contact angle of 152° for a 5μL droplet that does not slid off even when the sample is held upside down. This synthetic emulsion is simple and convenient as impregnating agent for filter paper, which can be considered as a suitable candidate for various substrates such as cotton textiles, E-glass and artificial fiber, and so on.

Preparation and Characterization of Fluorinated Epoxy Resin Emulsion for Waterborne Coatings

Under the action of initiator(BPO), the α-methyl acrylic acid (α-MAA), butyl hexafluorobutyl methacrylate (HFMA) and other monomers are graft copolymerized into epoxy molecular. By adding N, N-dimethyl ethanolamine, fluorine-containing water-based epoxy resin emulsion can be prepared. By orthogonal experiments, the amount of acrylic monomer, BPO dosage, grafting temperature and other optimum conditions can be determined. Infrared spectroscopy (FT-IR) characterization confirms acrylic monomers successfully grafted to the epoxy resin molecules. The study focuses on the effect of different content of HFMA on modified emulsion particle size and contact angle of coating. The results shows that the introduction of HFMA monomer made the smallest average particle size of emulsion low to 165 nm, and the contact angle against water is increased by 20°. After determining the conventional and environmental performance of the emulsion, the results shows that this preparation of epoxy resin emulsion can fully meet the requirements of waterborne coatings.

Study on Environment-Friendly Epoxy Emulsion Modified by Two Silane Coupling Agents

The environment-friendly epoxy emulsion was synthesized by MAA, BA, St reacting as grafting monomer, while silane coupling agents played a role as functional monomer. Experimental results were characterized by Nano-particle size analyzer, EIS, UV-VIS spectrophotometer, FTIR and TGA. The results of Nano-particle size analyzer showed the average particle size lower than 300nm and emulsion had lowest water absorption when ω(KH560+KH550) was 7%. The results of EIS and UV-VIS spectrum showed the cured firm had the best corrosion resistance and weather resistance while n(KH560):n(KH550)=2:1. The results of FTIR showed the silane coupling agents had successfully grafted in the skeletal structure of epoxy molecules. The results of TGA showed the thermal stability were better than unmodified.

Influences of molecular weight of epoxy binder on fire protection of waterborne intumescent fire resistive coating

Epoxy emulsions with different number average molecular weight ( M ¯ n = 446, 568, 1025 and 1739 g/mol) were used as polymer binders for preparation of waterborne intumescent fire resistive coating. The influences of M ¯ n of the epoxy resin on the properties and char formation of the coatings were investigated in detail by TGA, FTIR, EDS, SEM, rheological measurement and fire protection test. The TGA, FTIR and EDS results proved that epoxy binder with high molecular weight could improve thermal stability of the coating and enhanced anti-oxidation of the char layer at high temperature. The rheological results showed that the melting viscosity of epoxy binder increased with increase of M ¯ n , and the increasing melting viscosity of epoxy binder could slow down the expansion speed of the coating and also lead to an increase of the cell size of the char layer. The coating using epoxy with M ¯ n of 1025 g/mol as binder had good fire protection. However, epoxy binder with excessive high molecular weight led to formation of loose and uneven foam structure, which could significantly reduce the fire protection of the coating.

Study of Epoxy Resin Emulsion by Emulsion Graft Polymerization

In the paper, the emulsion graft polymerization is used to prepare stable epoxy resin emulsion by vinyl acetate and polyvinyl alcohol (PVA) as emulsification stabilizer. It is studied for the influence on the properties of emulsion by temperature and dosages of functional monomer, acrylamide and acrylic acid, and initiator. The results show that the optimal conditions: reactive temperature is 75°C, acrylic acid is 2%~4%(mass concentration), acrylamide is 2%~4%(mass concentration) and initiator is 0.7%~0.8%(mass concentration).

Mechanical Properties of Oil Filter Paper Impregnated by a Novel Waterborne Novolac Epoxy Emulsion

A novel cationic waterborne epoxy emulsion for oil filter paper was synthesized. Hydrophilic groups were introduced into a multifunctional bisphenol-A novolac epoxy resin (NEP) by chemical modification, while maintaining the epoxy groups as many as possible, which were neutralized to form the equably water dispersed epoxy resin. The structure of modified NEP in different rate of ring-opening was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The emulsion particle dispersion and micromorphology of waterborne bisphenol-A novolac epoxy resin (WNEP) was detected by granularity measured instrument and TEM. Mechanical properties and microstructure of oil filter papers impregnated by five different waterborne epoxy emulsions were tested and observed by SEM. From the results it can be shown that oil filter paper impregnated by WNEP emulsion has comprehensive properties better than other four commercialized products, exhibiting the best air permeability and improved bursting strength15% higher than that impregnated by poly-styrene-acrylate (PSA) latex.

Specific features of emulsification of epoxy resins in aqueous solutions of nonionic surfactants

The conditions of emulsification of imported analogs of Russian epoxy resins in the presence of nonionic surfactants were studied. The curing kinetics and the hardness of coatings formed from compounds containing epoxy emulsions and EPILINK 701 and Waterpoxy 751 curing agents were examined.

Waterborne crackle decorative coatings and crack patterns

A preparation method of waterborne crackle decorative coatings was reported in this paper and the factors that influence crack patterns were investigated. The crackle coating consisted of a waterborne basecoat and a waterborne topcoat. The basecoat was made from two-component epoxy emulsion and the topcoat was made from fluorine-containing acrylic emulsion, silicone-acrylic emulsion or styrene-acrylic emulsion. Three junction types of crack patterns were prepared by the three top coatings, which were T-junction, Y-junction and mixed junction. T-junction type with long and straight cracks was prepared from styrene-acrylic emulsion 296DS. Y-junction type with curve and short cracks was prepared from fluorine-containing acrylic emulsion A603C and mixed junctions type was made from silicone-acrylic emulsion. Crack patterns with different spacing were prepared by controlling the thickness of topcoat, dryness of basecoat or conditions of film forming. The characterize methods of type and spacing for crack pattern were developed and properties of coating film including adhesion, water resistance, scrub resistance and so on were tested. The results showed that the crackle coatings possessed satisfactory properties for practical application.