Polyether-based TPU

Polyether-based TPU is a type of thermoplastic polyurethane elastomer. Its English introduction is as follows:

### Composition and Synthesis Polyether-based TPU is mainly synthesized from 4,4′-diphenylmethane diisocyanate (MDI), polytetrahydrofuran (PTMEG), and 1,4-butanediol (BDO). Among them, MDI provides a rigid structure, PTMEG constitutes the soft segment to endow the material with flexibility, and BDO acts as a chain extender to increase the molecular chain length. The synthesis process is that MDI and PTMEG first react to form a prepolymer, and then the prepolymer undergoes a chain extension reaction with BDO, and finally, polyether-based TPU is formed under the action of a catalyst.

### Structural Characteristics The molecular chain of TPU has an (AB)n-type block linear structure, where A is a high-molecular-weight polyether soft segment with a molecular weight of 1000-6000, B is generally butanediol, and the chemical structure between the AB chains is diisocyanate.

### Performance Advantages -

**Excellent Hydrolysis Resistance**: The polyether bond (-O-) has much higher chemical stability than the polyester bond (-COO-), and is not easy to break and degrade in a water or hot and humid environment. For example, in a long-term test at 80°C and 95% relative humidity, the tensile strength retention rate, a polyether-based TPU, exceeds 85%, and there is no obvious decrease in the elastic recovery rate. – **Good Low-Temperature Elasticity**: The glass transition temperature (Tg) of the polyether segment is lower (usually below -50°C), which means that polyether-based TPU can still maintain good elasticity and flexibility in a low-temperature environment. In a -40°C low-temperature impact test, there is no brittle fracture phenomenon, and the difference in bending performance from the normal temperature state is less than 10%. – **Good Chemical Corrosion Resistance and Microbial Resistance**: Polyether-based TPU has good tolerance to most polar solvents (such as alcohol, ethylene glycol, weak acid and alkali solutions), and will not swell or dissolve. In addition, the polyether segment is not easily decomposed by microorganisms (such as mold and bacteria), so it can avoid performance failure caused by microbial erosion when used in a humid soil or water environment. – **Balanced Mechanical Properties**: Taking as an example, its Shore hardness is 85A, which belongs to the category of medium-high hardness elastomers. It not only retains the typical high elasticity and flexibility of TPU, but also has sufficient structural strength, and can achieve a balance between “elastic recovery” and “shape stability”. Its tensile strength can reach 28MPa, the elongation at break exceeds 500%, and the tear strength is 60kN/m.

### Application Fields Polyether-based TPU is widely used in fields such as medical treatment, automobiles, and outdoors. In the medical field, it can be used to make medical catheters due to its good biocompatibility, hydrolysis resistance and microbial resistance. In the automotive field, it can be used for engine compartment hoses, door seals, etc. because of its ability to withstand high temperature and humidity environments, low-temperature elasticity and ozone resistance. In the outdoor field, it is suitable for making outdoor waterproof membranes, in low-temperature environments, etc.