The main raw materials of polyurethane are diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI) and polypropylene glycol (PPG), which have become international commodities. The production technology and equipment of these raw materials are very complicated, and the product competition is fierce. Due to long-term development, production is relatively concentrated.
Isocyanate is a general term for all kinds of isocyanates. If classified according to the number of-NCO groups, it includes monoisocyanate R-N = C = O, diisocyanate O = C = N-R-N = C = O and polyisocyanate. It can also be divided into aliphatic isocyanate and aromatic isocyanate. At present, aromatic isocyanates, such as MDI and TDI, are used the most.
Application:
1, clothing and sporting goods
Polyurethane is widely used in clothing industry. Its representative products are comfortable, soft, elastic and elastic high-elastic fibers and leather products. In addition to women's underwear and socks, its amazing extensibility is fully exerted in ski shirts and swimsuits.
2. necessities of life
At home, the use of polyurethane products has created a comfortable living environment for us. Polyurethane paint has a beautiful gloss on the surface of furniture, piano and other musical instruments, which plays a solid protective role. Soft foam is widely used as cushion material and healthy bedding to disperse the pressure brought to human body.
In the kitchen, rigid foam is used as heat insulation material for refrigerators and so on, and polyurethane resin with good adhesion to plastic films is used as adhesive for food packaging.
3. Electronic products
Promoting the development of electronic industry is the mission of polyurethane. Polyurethane adhesive has excellent wear resistance and adhesion, and is used as magnetic adhesive for various recording media such as audio tapes, video tapes, computer disks, rechargeable cards and electronic tickets, which improves the recording density.
Baidu encyclopedia-polyurethane