GT70 - Abstract Preview
GT70
Symposium: S01 - General Session
Poster Presentation
 
 

Process depending morphology and resulting physical properties of TPU

Frick Achim (1)*, Spadaro Marcel (1)

(1) Aalen University - Baden-Württemberg - Germany

Thermoplastic polyurethane (TPU) is a rubber like material with outstanding properties, e.g. for seal applications. TPU basically provide high strength, low frictional behavior and excellent wear resistance. Though, due to segmented structure of TPU composed of hard and soft segments (HS, SS), physical properties depend strongly on morphological arrangement of the phase separated HS at a certain ratio of HS to SS. It is obvious that the TPU deforms differently depending on its bulk morphology. Basically, the morphology can either consist of HS segregated into small agglomerates, which are well dispersed in the SS matrix or of few strongly phase separated large size HS domains embedded in the SS matrix. The morphology development is hardly ruled by the melt processing conditions of the TPU. Depending on the morphology the TPU provides quite different physical properties with respect to strength, deformation behavior, thermal stability, creep resistance and tribological performance. The paper deals with the influence of important melt processing parameters, such as temperature, pressure and shear conditions, on the resulting physical properties tested by tensile and relaxation experiments. Further the morphology is studied employing dynamic scanning calorimeter (DSC), light microscopy (LM) and scanning electron beam microscopy (SEM) investigations. Correlations between processing conditions and resulting TPU material properties are elaborated. Flow and shear simulations contribute to the understanding of thermal and flow induced morphology development.