Polyurethane materials are a general term for a class of macromolecular compounds that have urethane structures in their molecular structure. They are usually prepared by the polyaddition reaction of diisocyanates and polyols. Polyurethane polymers possess both polar functional groups that allow for physical cross-linking and non-polar and flexible chain segments. When used properly, these polar functional groups can also undergo further chemical cross-linking. These molecular characteristics give polyurethane materials high strength, toughness, and solvent resistance. As a high-strength, weather-resistant, and highly adhesive material, polyurethane has been widely used in the coatings field. Based on the type of isocyanate used to prepare the polyurethane, polyurethane emulsions and corresponding paints can be divided into two main categories: aliphatic and aromatic. Aliphatic paint films have excellent weather resistance and anti-yellowing properties; aromatic water-based polyurethanes are mostly used for interior decorative paints. According to the size of the particles obtained during polymerization, there are two types: polyurethane emulsions and polyurethane dispersions. Water-based polyurethane dispersions use a unique process to disperse polyurethane particles in water, thus achieving film formation with water as the carrier. Similar to other emulsion film-forming mechanisms, the film-forming effect depends on the ability of the polymer molecules to interpenetrate between the particles. To increase penetration, on the one hand, the polyurethane molecular chains must be sufficiently flexible and have good fluidity; on the other hand, the emulsion particles should be as small as possible to increase the contact area between the particles and reduce the movement distance of the polymer molecules. Water-based polyurethane dispersions usually have nano-sized particles, appearing translucent or even completely transparent, and are one of the best water-based paint base materials. Water-based polyurethane dispersions are sometimes called nano-emulsions to distinguish them from ordinary emulsions, which have a white appearance. Room 1013, Building A5, Financial Port Center, Yangzijiang Road, Baohe District, Hefei City， Anhui province, China +86 0551 63459511 sales@sinogracechem.com vivisinograce@outlook.com +8615755193346 http://www.sinogracechem.com

Characteristics of Acrylic Polyurethane Topcoat Acrylic polyurethane paint, formed by the reaction of hydroxyl-containing acrylic ester and aliphatic polyisocyanate such as HDI trimer, has a paint film with excellent hardness and flexibility, and good chemical resistance. Its outstanding weather resistance, high gloss, good drying properties, and fast surface drying without dust adhesion make it the preferred topcoat in heavy-duty anti-corrosion coating systems. Due to its high hardness and excellent surface gloss, it is also used as polyurethane enamel and acrylic polyurethane enamel. Among polyurethane coatings and even all types of coatings, two-component solvent-based polyurethane coatings have excellent performance and therefore account for a large proportion. Among them, two-component acrylic polyurethane coatings are a new type of coating developed in recent years. Because their macromolecular structure contains both urethane chain segments and acrylic carbon-carbon long chain segments, they combine the advantages of both types of coatings. Durability: Acrylic polyurethane topcoats have very good durability, especially in terms0 of yellowing resistance. In a dry environment, they can withstand temperatures up to 120°C, but some aging and yellowing may occur. If long-term color retention is required, the maximum operating temperature for equipment and pipelines is recommended not to exceed 80°C. Applying too thick a coat can lead to blistering or poor film formation, affecting its performance. Chemical Resistance: Acrylic polyurethane topcoats have good resistance to chemicals, crude oil, gasoline, and general solvents, but their chemical resistance is not as good as polyester polyurethane topcoats. Paint Film Hardness: The hardness of acrylic polyurethane topcoats is not as good as epoxy topcoats, so epoxy topcoats can be used in areas such as ship decks or walkways. In the early stages of curing, acrylic topcoats are quite flexible and thermoplastic. Therefore, adhesion testing on newly applied topcoats may show relatively poor results. Adhesion will improve over the following weeks. This is mainly due to the product being applied at low temperatures or applied too thickly, or it could also be due to the primer being applied too thickly, allowing solvents to remain and react with isocyanates, such as certain epoxy primers containing butanol solvents Temperature resistance: Acrylic polyurethane paint loses its gloss quickly in high humidity and high-temperature environments. Low temperature and high humidity environments, as well as condensation or rainwater on the surface immediately after application, can lead to discoloration, loss of gloss, and blistering of the paint film.

Characteristics of Acrylic Polyurethane Topcoat Acrylic polyurethane paint, formed by the reaction of hydroxyl-containing acrylic ester and aliphatic polyisocyanate such as HDI trimer, has a paint film with excellent hardness and flexibility, and good chemical resistance. Its outstanding weather resistance, high gloss, good drying properties, and fast surface drying without dust adhesion make it the preferred topcoat in heavy-duty anti-corrosion coating systems. Due to its high hardness and excellent surface gloss, it is also used as polyurethane enamel and acrylic polyurethane enamel. Among polyurethane coatings and even all types of coatings, two-component solvent-based polyurethane coatings have excellent performance and therefore account for a large proportion. Among them, two-component acrylic polyurethane coatings are a new type of coating developed in recent years. Because their macromolecular structure contains both urethane chain segments and acrylic carbon-carbon long chain segments, they combine the advantages of both types of coatings. Durability: Acrylic polyurethane topcoats have very good durability, especially in terms0 of yellowing resistance. In a dry environment, they can withstand temperatures up to 120°C, but some aging and yellowing may occur. If long-term color retention is required, the maximum operating temperature for equipment and pipelines is recommended not to exceed 80°C. Applying too thick a coat can lead to blistering or poor film formation, affecting its performance. Chemical Resistance: Acrylic polyurethane topcoats have good resistance to chemicals, crude oil, gasoline, and general solvents, but their chemical resistance is not as good as polyester polyurethane topcoats. Paint Film Hardness: The hardness of acrylic polyurethane topcoats is not as good as epoxy topcoats, so epoxy topcoats can be used in areas such as ship decks or walkways. In the early stages of curing, acrylic topcoats are quite flexible and thermoplastic. Therefore, adhesion testing on newly applied topcoats may show relatively poor results. Adhesion will improve over the following weeks. This is mainly due to the product being applied at low temperatures or applied too thickly, or it could also be due to the primer being applied too thickly, allowing solvents to remain and react with isocyanates, such as certain epoxy primers containing butanol solvents Temperature resistance: Acrylic polyurethane paint loses its gloss quickly in high humidity and high-temperature environments. Low temperature and high humidity environments, as well as condensation or rainwater on the surface immediately after application, can lead to discoloration, loss of gloss, and blistering of the paint film.

Environmental Friendliness: Water-based acrylic resins use water as a solvent and do not produce harmful gases or pollutants during use, meeting environmental protection requirements. Weather Resistance: They have good weather resistance and can be used under various climatic conditions, being less susceptible to the effects of ultraviolet light, oxygen, and humidity. Good Adhesion: They exhibit good adhesion and can bond to a variety of substrates (such as metals, glass, ceramics, fibers, etc.). Fast Drying: After dissolving in water, water-based acrylic resins can quickly form a hard, wear-resistant film through heating or air drying. Good Adjustability: They have good adjustability and can be diluted, colored, and filled as needed to obtain the desired properties. Molecular Structure Design: Molecular structure design is the core of water-based acrylic resin design. By selecting appropriate acrylate monomers, the resin's performance can be adjusted. Monomer Composition: Common hydroxyl-containing functional monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate can form hydrogen bonds with water, improving the hydrophilicity of the resin. Carboxyl Monomers: Such as methacrylic acid and acrylic acid, can undergo ring-opening addition reactions with epoxy groups, or form amide bonds with amino resins under acidic or alkaline conditions. Amide Monomers: Amide monomers such as acrylamide enhance intermolecular forces, improving the water solubility, chemical activity, thermal stability, and thermal properties of the polymer. Epoxy Monomers: Epoxy monomers can undergo ring-opening reactions with nucleophiles such as primary amines, thiols, or hydroxyl groups under mild conditions, improving the hardness, gloss, adhesion, UV absorption performance, and thermal stability of the copolymer. Fluorine-containing Acrylic Monomers: The complete monomers can be detected in GCMS and PGC spectra, and special elements can be screened using XRF, while IC can be used for absolute quantification of fluorine-containing acrylic monomers. Bromine-containing Acrylic Monomers: These improve the flame retardant properties of the resin and are often used in interior decoration materials such as curtains and carpets in buildings. Sulfonic acid-based acrylic monomers: improve the hydrophilicity and water absorption properties of copolymers; reduce the friction coefficient and improve lubrication; the sulfonic acid group complexes with Fe3+, increasing the rigidity of the hydrogel; and improve temperature, salt, and shear resistance. Room 1013, Building A5, Financial Port Center, Yangzijiang Road, Baohe District, Hefei City， Anhui province, China +86 0551 63459511 sales@sinogracechem.com vivisinograce@outlook.com +8615755193346 http://www.sinogracechem.com