TPU Introduction

Thermoplastic polyurethane (TPU) is a melt-processable thermoplastic elastomer with high durability and flexibility. It has the characteristics of both plastic and rubber and thus exhibit properties like durability, flexibility as well as excellent tensile strength.

TPU, a new generation of thermoplastic elastomer material. Its structure includes hard segment and soft segment, made by polyols, isocyanate and chain extender by condensation reaction.
The features of TPU include environmental-friendly, easy processing, diversified performance, recycling etc.；TPU has excellent physical property, abrasion resistance, easy coloring, high elasticity, weather resistance, oil resistance and low temperature flexibility etc., widely used in phone case, overmolding, shoes, film, adhesive, belt & conveyor, wire & cable etc.

According to polyols type, TPU can be divided into polyester grade, polyether grade, polycaprolactone grade and polycarbonate grade etc.；according to isocyanate type, TPU can be divided into aromatic TPU and aliphatic TPU. Different kinds of TPU have different property, can be used in different application. The hardness range of TPU is wide, covering 50A-85D.

• Soft Segment (polyether or polyester): It is built out of a polyol and an isocyanate which provides flexibility and elastomeric character of a TPU.
• Hard Segment (aromatic or aliphatic): It is constructed from a chain extender and isocyanate giving TPU its toughness and physical performance properties
  1. Aromatic TPUs – based on isocyanates such as MDI
  2. Aliphatic TPUs – based on isocyanates like HMDI, HDI and IPDI

Thermoplastic polyurethanes are elastic and melt-processable. Additives can improve dimensional stability and heat resistance, reduce friction, and increase flame retardancy, fungus resistance, and weatherability.

Aromatic TPUs are strong, general-purpose resins that resist attack by microbes, stand up well to chemicals. An aesthetic drawback, however, is the tendency of aromatics degrade by free radical pathways induced by exposure to heat or ultraviolet light. This degradation leads to product discoloration and loss of physical properties.

Additives such as antioxidants, UV absorbers, hindered amine stabilizers are used to protect polyurethanes from UV light-induced oxidation and hence make thermoplastic polyurethanes suitable for wide range of applications that may require both thermal and/or light stability.

Aliphatic TPU, on the other hand, are inherently light stable and resist discoloration from UV exposure. They are also optically clear, which makes them suitable laminates for encapsulating glass and security glazing.