Influence of strain rate on tensile behavior of polyethersulfone thermoplastic

Abstract

Polyethersulfone (PES) is a high-performance thermoplastic widely used in structural applications. This study investigates how different strain rates affect the tensile behavior and structural properties of PES. Specimens were fabricated via injection molding and tested under uniaxial tension at strain rates of 1, 5, 10, and 25 mm/min. The tensile strength increased from 60.12 MPa at 1 mm/min to 83.84 MPa at 25 mm/min, while the tensile modulus rose from 2.78 GPa to 3.18 GPa. The maximum elongation reached 21.15% and the energy absorbed peaked at 28.01 kN-mm at a strain rate of 5 mm/min. FTIR analysis showed marked shifts in the hydrogen bonding and ether group peaks, especially at 5 mm/min, indicating enhanced polymer chain alignment. UV spectra revealed a significant reduction in absorption intensity between 320 and 400 nm for samples with greater plastic deformation. XRD studies confirmed an increase in crystallinity, with the highest value of 48.30% observed at 5 mm/min and a corresponding decrease in d-spacing. Thermal imaging captured localized temperature rises that support the role of strain rate in influencing chain mobility. Overall, the results demonstrate that adjusting the strain rate can significantly modify the mechanical and structural properties of PES.