Abstract:

Uniaxial tensile tests of ethylene-chloro-tri-fluoro-ethylene (ECTFE) foils were conducted at a thickness of 250 μm and various low and high temperatures (-50, -40, -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, and 80 ℃). The specimens were fabricated according to the machine direction (MD). The tensile stress-strain curves of the foils at various temperatures were obtained. According to the variation discipline with temperature, several parameters such as elastic modulus, yield stress, yield strain, cold drawing stress, tensile strength, and tensile strain at break were subsequently analyzed and calculated. The results show that with the elevation of the stress-strain curves, the yield strength, tensile strength, cold drawing stress, and elastic modulus increase, but the strain at break and toughness decrease when the temperature decreases. At a wide range of temperatures from -50 ℃ to 80 ℃, the difference of elastic modulus can increase up to 93%, with a yield stress of 89%, which reflects the great sensitivity of ECTFE to temperatures. The fitting formulas of main mechanical parameters are also obtained, which can be used to predict the mechanical properties of ECTFE foils at various temperatures.

Key words: ethylene-chloro-tri-fluoro-ethylene (ECTFE) foils, low and high temperature environment, uniaxial tensile test, elastic modulus, yield stress