Thermoplastic polyurethane elastomer, referred to as TPU, also known as PU thermoplastic, is a linear block copolymer composed of oligomer glycol soft segments and diisocyanate-chain extender hard segments.

The main uses of TPU are: automobile parts and machine parts, sports shoe soles, rubber rollers, wires and cables, hoses, films and sheets, fabrics (coatings and high elastic clothing and socks, etc.), tape adhesives, fabric coatings, adhesives wait.

TPU can be divided into polyester type, polyether type, etc. according to the soft segment structure. According to the classification of structural characteristics, TPU can be divided into full thermoplastic and semi-thermoplastic. The former has no chemical cross-links between molecules, only physical cross-links mainly hydrogen bonds, and is soluble in solvents such as dimethylformamide; the latter contains a small amount of allophanate chemical cross-links between molecules These chemical cross-linking bonds are thermodynamically unstable and will break at processing temperatures above 150°C, and will be regenerated after molding and cooling. The existence of a small amount of chemical cross-linking bonds plays an important role in improving the compression set and tear set properties of the product.

Similar to other thermoplastics, thermoplastic polyurethane has rubber-elastic or plastic properties at room temperature, melts at high temperatures, becomes a viscous fluid and can be processed in the same way as thermoplastics. Thermoplastic polyurethane relies on intermolecular hydrogen bonds to form physical cross-links and has high mechanical strength. The main difference between thermoplastic polyurethane and cast polyurethane lies in the different processing and molding methods and the different types of chain extenders. Thermoplastic polyurethane can be polymerized by bulk melt polymerization or solution polymerization.

Commercial TPU is usually in granular form, and can be made into products or composite products of various shapes using thermoplastic processing methods such as extrusion, injection, calendering, blow molding, molding, etc. Among them, extrusion molding and injection molding are the most widely used, about Accounting for more than 70%. TPU is also used in the manufacture of elastic fibers, synthetic leather resins, adhesives and coatings.