Thermoplastic polyurethane (TPU) not only has the high-strength, high-wear resistance rubber properties of cross-linking polyurethane, but also has the thermoplastic function of linear polymer materials, and then its application can be extended to the plastic field. Especially in recent decades, TPU has become one of the fastest polymer materials. TPU film is an important application method of TPU data. In recent years, the development and advancement of high-tech has been more and more widely used. However, due to its difficult processing and unstable products, there are no manufacturers in mainland China that can carry out better mass production.
TPU film has excellent properties such as high strength, high toughness, abrasion resistance, oil resistance, cold resistance, aging resistance, environmental protection, non-toxicity and degradability which are unmatched by other plastics and rubber. It also has waterproof, moisture-proof, wind-proof, cold-proof, anti-bacterial and UV-resistant. Such excellent functions can be used in many industrial and civil fields. It is a green film and is a directional substitute for PVC film.
It can be seen from the above table that the functional TPU film is generally superior to the general-purpose plastic and rubber film. TPU film product is pided into two major categories of polyester and polyether. The polyester product has good heat resistance and chemical resistance, and is widely used in place of PVC products. Polyethers have better low temperature resistance, hydrolysis resistance, and mildew resistance, and are widely used in related products in contact with water.
TPU film function
TPU uses a wide range of temperature planning, most products can be used for a long time in the -40--80 °C plan, short-term operating temperature can reach 120 °C. The soft segment in the TPU macromolecular segment structure selects its low temperature function. Polyester TPU is less cold and sturdy than polyether TPU. The low temperature function of the TPU is determined by the glass transition of the soft segment and the softening temperature of the soft segment. The vitrification change plan depends on the content of the hard segment and the degree of phase difference between the soft and hard segments. Following the increase in the content of the hard segment and the decrease in the degree of phase separation, the vitrification modification plan of the soft segment is also widened accordingly, which will lead to the deterioration of the low temperature function. If a polyether with poor compatibility with the hard segment is selected as the soft segment, the low temperature flexibility of the TPU can be advanced. When the relative molecular weight of the soft segment is increased or the TPU is annealed, the degree of incompatibility of the soft and hard segments will also advance. At high temperatures, the hard segment is mainly used to maintain its function, and the higher the hardness of the product, the higher the operating temperature. In addition, the high temperature function is affected by the amount of chain extender, in addition to the amount of chain extender. For example, TPU using (hydroxyethoxy)benzene as a chain extender has a higher application temperature than TPU prepared from butanediol or hexanediol as a chain extender. The type of diisocyanate also has an effect on the high temperature function of the TPU, and the TPU obtained as a hard segment of different diisocyanates and chain extenders exhibit different melting points.