Influence of temperature on the compression properties of expanded thermoplastic polyurethane (ETPU)

This study explores how expanded thermoplastic polyurethane (ETPU) responds to temperature and compression at various temperatures. Dynamic mechanical thermal analysis (DMTA) was used to understand the temperature influence at small deformations. To investigate the deformation behavior at different compression stages we employed in-situ CT measurements and 3D strain mapping. Through quasi-static compression tests at temperatures from − 50 to 120 °C, we determined the influence of temperature on compression modulus, elastic stress, stress at 50% deformation, densification, and energy absorption. Remarkably, ETPU demonstrates robust recovery after compression, particularly within the − 50 to 60 °C temperature range. Subsequent compression tests show consistent or even slightly increased compression properties, such as a 10% increase in energy absorption for samples previously tested at − 40 °C, indicating that ETPU can withstand prior exposure to different temperatures.