对厚度为250 μm的乙烯-三氟氯乙烯共聚物(ECTFE) 薄膜进行了单轴拉伸试验,考虑了不同的低-高温度 (分别为-50、-40、-30、-20、-10、0、10、20、30、40、50、60、70及80 ℃) 效应,试件截取方向为机器方向.得到了ECTFE薄膜在不同温度下的拉伸应力-应变曲线,通过分析得到了弹性模量、屈服强度、屈服应变、冷拉应力、抗拉强度、断裂延伸率等力学参数及其随温度的变化规律.结果表明:随着温度的降低,应力-应变曲线整体向上抬升,屈服强度、拉伸强度、冷拉应力和弹性模量均增大,断裂延伸率和韧性均减小.在不同温度(-50~80 ℃)下,弹性模量的差值可达到93%,屈服强度的差值可达到89%,温度变化对ECTFE薄膜力学性能的影响显著.得出了主要力学参数和温度变化的拟合公式,可用于判断ECTFE薄膜在不同温度下的力学性能.

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.