Product Description YLSE-0500 / YLSE-0510 is a high-temperature-resistant trifunctional epoxy resin based on p-aminophenol. The molecular structure contains multiple epoxy groups and aromatic rings, enabling the cured system to form a high crosslink density and aromatic density during curing. As a result, the cured material exhibits excellent heat resistance, high mechanical strength, low curing shrinkage, and good resistance to radiation, water, and chemicals. In addition, its low viscosity makes it easy to process and suitable for solvent-free operations. It is used in electrical insulation castings requiring high thermal resistance, as well as composite manufacturing processes such as carbon fiber and glass fiber filament winding, pultrusion, lamination, and prepreg production. The glass transition temperature (Tg) can exceed 200 °C.   Product Name 4-(2,3-Epoxypropoxy)-N,N-di(2,3-epoxypropyl)aniline CAS No.: 5026-74-4   Structural Formula   Technical Specifications   YLSE-0500 YLSE-0510 Appearance Brown liquid Yellow liquid EEW, g/eq 100-115 93-106 Viscosity, cps@25°C 1500-6000 500-1000 Volatiles, % Max. 1.5 Max.1.0   Main Applications High-temperature structural adhesives Carbon fiber and glass fiber composites for pultrusion and filament winding Electrical insulation materials High-temperature epoxy casting systems used in vacuum casting (RTM, VARTM) and Automatic Pressure Gelation (APG) Potting and sealing of miniature motor components High-temperature epoxy diluent   Properties of Neat Resin Castings Comparison of Casting Performance between YLSE-0500 and YLSE-0510 Using DDS (4,4'-diaminodiphenyl sulfone) as the curing agent, selected performance properties of castings made from YLSE-0500 and YLSE-0510 epoxy resins were tested. Casting preparation procedure: • Heat DDS to 200 °C (melting point 176 °C) until melted. • Preheat the epoxy resin to 100 °C. • Slowly add DDS into the epoxy resin while stirring until uniform. • Defoam under vacuum for 15 minutes. • Pour into molds and heat-cure.   The performance indicators of the resulting castings are shown in the table below: Brand type YLSE-0500 YLSE-0510 Curing agent name DDS Curing agent addition amount phr 49 Curing condition 0.5h/80°C+1h/100°C+1.5h/120°C+2h/180°C Tg(DMA method) °C 245-250 260-270 Bending performance at 25°C Strength Mpa 132 136 Modulus  Gpa 3.5 3.4 Tensile properties at 25°C Strength Mpa 64 70 Modulus  Gpa 3.8 3.6 Elongation at break  % 2.3 2.8   Casting Properties of YLSE-0500 with Methyl Tetrahydrophthalic Anhydride (MTHPA) YLSE-0500 epoxy resin is commonly used together with aromatic amine curing agents (such as diaminodiphenyl sulfone and diaminodiphenylmethane) and anhydride curing agents (such as methyl nadic anhydride, methyl tetrahydrophthalic anhydride, and methyl hexahydrophthalic anhydride).   The casting properties of YLSE-0500 cured with methyl tetrahydrophthalic anhydride (MTHPA) at 25 °C are shown in the table below: Tensile strength Mpa Bending strength Mpa Impact strength Kj/m2 Elongation at break  % Tg(DSC)  %  20-30 90-100 8-10 1.5-2.5 190-200 Mixing ratio(Phr): YLSE-0500/MTHPA=100/150 Curing conditions: 80℃/2h+100℃/2h+130℃/2h+180℃/3h   Precautions Due to its high functionality and high epoxy value, the curing process generates a large amount of heat, so attention must be paid to preventing runaway polymerization. If the viscosity becomes too high and causes difficulty in use, the resin may be heated to 100–120 °C for 1 hour to reduce the viscosity. During heating, please open the container lid to prevent any risk of runaway polymerization.   Equivalent Grades Similar domestic and international product grades include MY-0500, MY-0510, AFG-90, AFG-90H, etc.

Why is YLSE-721 our star product? What makes it so “hardcore”?   YLSE-721 is a high-performance, amino-based tetrafunctional liquid epoxy resin — an “industrial-grade bonding master” designed specifically for high-strength and high heat-resistant applications. Its name reveals the secret: “tetrafunctional” means each molecule contains four reactive sites, like a “multi-armed warrior” that can form a denser and stronger cross-linked network with curing agents. This is the key reason why its strength far exceeds that of ordinary difunctional epoxy resins. Meanwhile, its liquid form provides excellent flowability, making it ideal for potting, coating, or filling complex structures, ensuring easy and efficient application. What truly impresses users are its “three highs”: high temperature resistance, fast curing, and superior mechanical strength. Heat resistance: Continuous service temperature up to 150°C, and short-term endurance above 180°C, far outperforming standard epoxies (typically ≤120°C). Perfect for engine surroundings, motor coils, and PCB protection under high-temperature conditions. 🔧 Curing speed: Fully cures within 30–60 minutes at 60–80°C, which is 2–3 times faster than conventional epoxy systems — a real time-saver for urgent projects. Mechanical properties: Tensile strength exceeds 50 MPa, flexural strength surpasses 80 MPa, with excellent impact resistance and dimensional stability. It resists cracking even under severe vibration or thermal cycling. In addition, YLSE-721 offers outstanding electrical insulation, oil resistance, water resistance, and chemical durability — truly earning its reputation as the “Iron Man of the industrial world.”   Product Information Chemical Name: N,N,N',N'-Tetraglycidyl-4,4'-diaminodiphenylmethane CAS No.: 28768-32-3 Structural Formula     Main Applications High-temperature resistant composites such as carbon fiber and glass fiber; Potting of electronic components (e.g. power modules, LED drivers); Impregnation and insulation protection for motors and transformer coils; Precision mold manufacturing, including bonding of metals, ceramics, and composites; Bonding and sealing of aerospace structural components; Wear-resistant repair and anti-corrosion coatings for heavy-duty mechanical parts.   Usage Instructions YLSE-721 can be formulated with amine-type, anhydride-type, or imidazole-type curing agents and coupling agents to prepare adhesives, casting compounds, or composite systems for applications requiring excellent heat resistance. Common curing agents include 4,4'-diaminodiphenyl sulfone (4,4'-DDS), 4,4'-diaminodiphenylmethane (DDM), methyl tetrahydrophthalic anhydride (METHPA), methyl nadic anhydride (MNA), and 2-ethyl-4-methylimidazole (2,4EMI). If the resin appears too viscous during use, it can be heated to an appropriate temperature to reduce viscosity before mixing. To improve toughness, additives such as liquid polysulfide rubber or liquid nitrile rubber can be incorporated.   Typical Cured Properties DDS DDM METHPA MNA Test Method Glass Transition Temperature (°C) 250-260 220-230 200-210 235-240 Tensile Strength (MPa) 75 50 50 45 Tensile Modulus (GPa) 3.5 3.3 3.2 3.6 Flexural Strength (MPa) 130 120 100 97 Flexural Modulus (GPa) 3.3 3.4 4.0 3.8 Elongation at Break (%) 2.8 1.6 1.9 1.1 Impact Strength (kJ/m²) 15 10 9 8 Resin-to-Hardener Ratio (by weight) 100:52 100:42 100:42 100:150 Curing Schedule 100℃*2h+130℃*2h+160℃*2h+180℃*2h+200℃*2h   Common Mistakes to Avoid ❌ Incorrect curing agent combination: YLSE-721 must be used with specific anhydride or aromatic amine curing agents. Using general-purpose epoxy hardeners may result in incomplete curing, soft texture, or drastically reduced heat resistance ⚠️. ❌ Neglecting surface preparation: The substrate must be thoroughly cleaned, dried, and sanded; otherwise, adhesion failure or “false bonding” may occur. ❌ Overheating during curing: Although the resin has high thermal resistance, curing should be kept within the recommended temperature range (usually 60–120°C). Excessive temperature may cause bubbling or discoloration.   Precautions Due to its high functionality and epoxy value, YLSE-721 releases a large amount of heat during curing, so precautions should be taken to prevent runaway polymerization. If the viscosity is too high for convenient use, preheat the resin to 100–120°C for about one hour to lower viscosity. ⚠️ When heating, keep the container lid open to prevent polymerization explosion. This epoxy resin is alkali-resistant but not resistant to strong acids.

YLEP-638 Structural Characteristics The molecular backbone of YLEP-638 is a phenolic novolac structure formed by the condensation of phenol and formaldehyde, providing a rigid aromatic framework. This backbone itself has very high thermal stability and rigidity. On this phenolic framework, the hydroxyl groups react with epichlorohydrin to introduce multiple epoxy groups, making it a typical multifunctional epoxy resin. Unlike standard bisphenol-A type epoxy resins (such as E-51, functionality ≈ 2), YLEP-638 usually has an average epoxy functionality of 3.5 to 4.0 or even higher. Performance Features of YLEP-638 Outstanding Heat Resistance Origin: High crosslink density (resulting from high functionality) and rigid aromatic backbone. Performance: The cured product exhibits extremely high glass transition temperature (Tg) and heat distortion temperature (HDT), typically above 200°C and even up to 250°C. It maintains mechanical strength and dimensional stability under high temperatures with excellent creep resistance. Exceptional Mechanical Strength and Modulus Origin: Dense three-dimensional crosslinked network and rigid molecular chains. Performance: The cured product shows very high hardness, compressive strength, tensile strength, and modulus, giving it strong load-bearing capacity. Excellent Chemical Resistance Origin: The high crosslink density creates a compact and chemically inert network structure, making it difficult for solvents or chemical agents to penetrate or swell the material. Performance: It offers outstanding resistance to a wide range of organic solvents, acids, and alkalis. Its chemical resistance, particularly at high temperatures, is far superior to that of conventional epoxy resins. Superior Electrical Insulation Properties Origin: Stable chemical structure and high crosslink density. Performance: Maintains excellent dielectric strength and volume resistivity even under high temperature and humidity conditions. Processing Challenges High Viscosity: Due to its high functionality and rigid structure, YLEP-638 has very high viscosity at room temperature and must be heated (e.g., to 60–80°C) for casting, impregnation, or prepreg preparation. High Brittleness: The high crosslink density and rigid structure also result in low toughness, poor impact resistance, and low elongation at break, so it often requires the addition of toughening agents. Main Applications of YLEP-638 YLEP-638 + DOPO Used to produce halogen-free phosphorus-containing epoxy systems, successfully incorporating efficient phosphorus-based flame-retardant units into a high crosslink density epoxy network. The resulting materials combine excellent mechanical properties, heat resistance, and flame retardancy, making them ideal for green electronic encapsulation, halogen-free PCBs, high-performance flame-retardant insulating materials, and aerospace composites. Also used in carbon fiber prepregs, tennis rackets, and golf clubs.   YLEP-638 + Methacrylic Acid / Styrene Used to produce high-temperature- and corrosion-resistant phenolic epoxy vinyl ester resins, widely applied in flue gas desulfurization (FGD), power plant desulfurization tower linings, chemical storage tanks, and scrubbers for harsh environments.   YLE-128 + YLEP-638 + YLE-601 or YLE-604 Used for solder mask inks in copper-clad laminates and for anti-corrosion, high-temperature coatings (such as 900–1200°C heat-resistant and anti-oxidation coatings).   YLEP-638 + Curing Agent DDS Used to produce epoxy insulating varnishes for VPI (Vacuum Pressure Impregnation) processes, forming a strong, integrated “armor” layer on electrical coils. This layer resists high-voltage breakdown and withstands the intense heat and mechanical stress generated during motor operation. It is an essential insulation material for modern high-end electrical equipment, used in high-voltage motors, wind power generators, and traction motor stator coils, providing both insulation and flame-retardant protection. Also used in the manufacture of insulating tubes, rods, and plates.

  Dicyandiamide curing agent belongs to the heating curing class of latent curing agent, solid at room temperature, insoluble in epoxy resin, dispersed in epoxy resin in the form of microparticles, through the heating reaction, once heated to the melting point of the vicinity of the start of the dissolution and rapid reaction curing.   Curing reaction of dicyandiamide The molecular structure of dicyandiamide contains a cyano group (-CN) in addition to four active hydrogens. Cyano group can also participate in the curing reaction as a functional group. The curing reaction temperature of dicyandiamide is generally in the range of 160~180°C, and the curing reaction time is 20~60 minutes. For bisphenol A epoxy resin with 190 epoxy equivalents, the theoretical dosage of dicyandiamide curing agent (calculated on the basis of active hydrogen equivalents) is 11.1 parts, but the actual dosage is often in the range of 4-10 parts (based on 100 parts of the resin by mass). Dicyandiamide micropowder is dispersed into the epoxy resin, has a suitable storage period, is stable in storage, does not delaminate, and does not cure.   The fineness of the dicyandiamide particles may vary from product to product. The finer the dicyandiamide particles, the more obvious the performance advantage for curing reaction Ultra-fine dicyandiamide particles are easier to be evenly dispersed into the epoxy resin liquid. Ultra-fine dicyandiamide particles can be better mixed and dissolved in the epoxy resin liquid than ordinary dicyandiamide.   Application areas of dicyandiamide curing compounds Dicyandiamide epoxy resin has good adhesive property, heat resistance and stable storage period. Dicyandiamide epoxy resins can be widely used in powder coatings, carbon fibre prepregs, heat curable inks, laminates, single component adhesives and other applications. Typical applications: Preparation of prepregs for the manufacture of reinforced composites (wind energy, automotive, aerospace, marine engineering and other industries). Electronic packaging materials, adhesives. Powder coatings (especially heavy duty anti-corrosion function). For epoxy-based adhesives (reinforced materials).   Nanjing Yolatech provides all kinds of high purity and low chlorine epoxy resins, including Bisphenol A epoxy resin, Bisphenol F epoxy resin, Phenolic epoxy resin, Brominated epoxy resin, DOPO modified phenolic epoxy resin, MDI modified epoxy resin, DCPD epoxy resin, Multifunctional epoxy resin, Crystalline epoxy resin, HBPA epoxy resin and so on. And we also could provide all kinds of curing agents or hardeners and diluents.   We will be at your service 24 hours a day. Pls contact us freely.    

Epoxy resin adhesive is a reprocessing or modification of epoxy resin to make its performance parameters meet specific requirements. Usually epoxy resin adhesives are also used with curing agents and need to be mixed well to be fully cured. Generally, the epoxy resin adhesive is called A adhesive or main agent, and the curing agent is called B adhesive or curing agent(hardener).   Main properties of epoxy resin adhesives before curing Colur, viscosity, specific gravity, proportioning, gel time, open time, curing time, thixotropy (flow stopping), hardness, surface tension, etc.   Main properties of epoxy resin adhesive after curing Resistivity, proof voltage, water absorption, compressive strength, tensile strength, shear strength, peel strength, impact strength, heat deflection temperature under load, glass transition temperature, internal stress, chemical resistance, elongation, shrinkage coefficient, thermal conductivity, electrical conductivity, weathering resistance, aging resistance, dielectric constant.   Curing characteristics of epoxy resin adhesive Most of the epoxy resin adhesives are heat-setting adhesives. The higher the temperature of the epoxy resin adhesive, the faster the curing. The more the amount mixed at one time, the faster the curing. The curing process has exothermic phenomenon, etc.   Nanjing Yolatech provides all kinds of high purity and low chlorine epoxy resins, including Bisphenol A epoxy resin, Bisphenol F epoxy resin, Phenolic epoxy resin, Brominated epoxy resin, DOPO modified phenolic epoxy resin, MDI modified epoxy resin, DCPD epoxy resin, Multifunctional epoxy resin, Crystalline epoxy resin, HBPA epoxy resin and so on. And we also could provide all kinds of curing agents or hardeners and diluents. We will be at your service 24 hours a day. Pls contact us freely.  

Background Under normal conditions, bisphenol A-type liquid epoxy resins are colorless, transparent and flowable. When the external temperature is lowered, the molecular chain is less active and prone to crystal seeding. Liquid epoxy resin appears grey in color, free-floating crystals, crystal clusters, or hard lumps like curing, we call it the crystallization phenomenon.   Reasons for the crystallization of epoxy resin The reasons for the crystallization of epoxy resin are complex, we mainly summarize the following. High purity. We all know that crystals are highly pure substances, and so is epoxy resin, the higher the purity, the narrower the molecular distribution, the easier it is to crystallize. Low viscosity. The lower the viscosity, the faster the crystallization. Impurities. solid impurities are usually crystalline species for crystal growth, and the addition of certain precipitating pigment fillers can easily lead to crystallization. In contrast, larger particle sizes and higher additions are less likely to induce crystallization. Temperature. A narrow temperature cycle of 20-30°C is a common cause of crystallization, with diurnal temperature fluctuations initiating or accelerating the rate of crystallization. In addition, ultra-low temperatures (below 5°C) will accelerate crystallization. Moisture. The higher the moisture content, the more likely crystallization will occur.   Does crystallization affect the properties of epoxy resins? The crystallization phenomenon does not affect the performance of the epoxy resin, only the epoxy resin morphology has changed, not deterioration. However, it brings a lot of inconvenience to the operation. After practice, the crystalline epoxy resin is dissolved by heating and mixed with the corresponding proportion of curing agent, its tensile strength, flexural strength, compressive strength, and bonding strength have no change in comparison with epoxy resin without crystallization. It can be seen that the crystallization phenomenon does not affect the performance of the epoxy resin, only the epoxy resin morphology has changed, not a qualitative change. In general, the crystallization of epoxy resin adhesive is a reversible process that can be changed with the temperature and has no effect on the bonding performance and reinforcing effect of epoxy resin cured products. Even if the crystallization occurs, heating until it softens and disappears, it can be used normally.   Nanjing Yolatech provides all kinds of high purity and low chlorine epoxy resins, including Bisphenol A epoxy resin, Bisphenol F epoxy resin, Phenolic epoxy resin, Brominated epoxy resin, DOPO modified phenolic epoxy resin, MDI modified epoxy resin, DCPD epoxy resin, Multifunctional epoxy resin, Crystalline epoxy resin, HBPA epoxy resin and so on. If you are interested in them, pls kindly contact us. We will be at service for you any time, thank you.