Injection molding aliphatic TPU for brighter color applications

摘要

TPU or Thermoplastics Polyurethane is divided into two families, aromatic and aliphatic TPU. Our focus in this paper is Aliphatic TPU. The demands on elastomeric plastics, particularly those destined for application where appearance is key are growing rapidly. Aromatic TPUs tend to turn yellow when exposed to sunlight or heat; this has prevented TPU from being used in automotive interiors applications or where brighter color retention TPU is needed. In this work, Elastollan~® LP9273 (ester type aliphatic TPU) is compared to Elastollan C85A (ester type aromatic TPU) and Elastollan 1185A (ether type aromatic TPU). Various testing methods were applied to characterize mechanical and thermal properties; yellowness index, heat aging, QUV and weathering properties are discussed. Four different colors were examined (White, Tan, Grey and Blue). We found that Elastollan~® LP9273 showed superior color retention when it compared to the other two materials.