Thermoplastic polyurethane elastomer is a (AB) type block linear polymer, A represents a high molecular weight polymer polyol (ester or polyether, molecular weight is 1000-6000), called long chain; B represents 2- Diols of 12 straight carbon atoms are called short chains.
In the structure of thermoplastic polyurethane elastomer, the A segment is called the soft segment, which has the characteristics of flexibility and softness, which makes the TPU have extensibility; the urethane chain formed by the reaction between the B segment and the isocyanate is called the hard segment. With rigid and hard properties, people can make TPU products with different physical and mechanical properties by adjusting the ratio of A and B segments.
Thermoplastic polyurethane elastomers can be divided into polyester type, polyether type and butadiene type according to the soft segment structure, which respectively contain ester group, ether group or butene group. According to the hard segment structure, it is divided into urethane type and urethane urea type, which are obtained from diol chain extender or diamine chain extender respectively. Commonly divided into polyester type and polyether type.