What is polyurethane (PU)?

Polyurethane (PU) is a kind of high molecular compound. Polyurethane can be divided into polyester type and polyether type. They can be made into polyurethane plastic (mainly foam plastic), polyurethane fiber (called spandex in China), polyurethane rubber and elastomer.

The main raw materials of polyurethane include 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 quite fierce. As a result of long-term development, the production is relatively concentrated.

isocyanate is a general term for various esters of isocyanate. If classified by the number of-－NCO groups, it includes monoisocyanate R-N = C = O, diisocyanate O = C = N-R-N = C = O and polyisocyanate, etc. It can also be divided into aliphatic isocyanate and aromatic isocyanate. At present, the amount of aromatic isocyanate is the largest, such as MDI and TDI.

application:

1. Clothing and sporting goods

Polyurethane is widely used in the clothing industry. Its representative products are high elastic fibers and leather products that are comfortable to wear, soft, flexible and flexible. In addition to underwear and socks for women, its amazing extensibility is fully exerted in ski shirts and swimsuits.

2. Daily necessities

At home, the use of polyurethane products has created a comfortable living environment for us. Polyurethane coating paints beautiful gloss on the surfaces of furniture, pianos and other musical instruments, and plays a solid protective role. Soft foam is widely used as cushion material, and it is also used in 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 film is used as adhesive for food packaging.

3. Electronic products

It is the mission of polyurethane to promote the development of electronic industry. Polyurethane adhesive with excellent wear resistance and adhesion is used in audio tapes, video tapes, computer disks, rechargeable cards and electronic tickets as magnetic adhesive for various recording media, which improves the recording density.

above content reference: Baidu Encyclopedia-Polyurethane