Polyurethane (abbreviated as PU) is the abbreviation of polyurethane, which is formed by the addition of polyisocyanate and polyhydroxy polymer. It is a polymer compound containing many repeated carbamate segments (- NHCOO -) on the main chain of the polymer. Polyurethane is the only synthetic polymer material with significant application value in the fields of plastic, rubber, foam, fiber, coating, adhesive and functional polymer among various polymer materials. Its products have penetrated into all aspects of the national economy, and it has become a special organic synthetic material with the most varieties, the most extensive use and the fastest development among the current polymer materials. Its outstanding performance and applications mainly include:
1. Polyurethane foam materials can be divided into hard foam, semi hard foam and soft foam: PU soft foam is a very ideal cushion material, and the cushion material is also the application field with the largest amount of soft foam; PU hard foam is the most ideal thermal insulation material for refrigeration equipment (such as refrigerator); The most typical application of PU semi-rigid foam is to prepare automobile bumper.
2. The DMF process of water extraction is adopted for the processing of synthetic leather slurry, which is relatively environment-friendly. Moreover, the synthetic leather produced has good moisture permeability and air permeability, soft, plump, light, and more rich in the style and appearance of natural leather. It is the most ideal substitute for natural leather and widely used in clothing, footwear, luggage, furniture, sports and other industries.
3. Polyurethane coating has strong adhesion, and the film has excellent wear resistance, water resistance and drug resistance. It is mainly used in furniture coatings, building materials coatings and industrial printing inks.
4. Polyurethane elastomer has good tensile strength, tear resistance, impact resistance, abrasion resistance, weather resistance, hydrolysis resistance, oil resistance and other advantages. It is mainly used for coating materials (such as protection of hoses, gaskets, tires, rollers, gears, pipes, etc.), insulators, soles, solid tires, etc.
5. The high resilience of polyurethane fiber (polyurethane fiber for short) is incomparable to all elastic fibers. In traditional textiles, the grade of traditional fabrics can be greatly improved by adding less than 5% of polyurethane fiber, showing a soft, comfortable, beautiful and elegant style.
6. The sole made of polyurethane sole liquid has low density, soft texture, comfortable wearing, good wear resistance, shock absorption and anti-skid performance, and is mostly used to manufacture high-grade leather shoes, sports shoes, tourism shoes, etc.
7. The low temperature and ultra-low temperature properties of polyurethane adhesives exceed those of all other types of adhesives, mainly used in packaging, construction, wood, automobile, shoemaking and other industries.
8. Polyurethane sealant is a material used to fill voids (holes, joints, seams, etc.), which has two functions: bonding and sealing. Polyurethane sealant, silicone sealant and polysulfide sealant constitute the three major varieties of high-grade sealant at present. China is the world's largest producer and consumer of polyurethane, accounting for about 45% of the world's polyurethane output. In recent years, with the consumption upgrading of building energy conservation, automobile, household appliances, clothing, furniture and other industries, the application scale and fields of polyurethane have been increasing