PVDF膜材在自然老化和人工加速老化下力学性能变化的相关性研究

Study on the correlation of mechanical properties of PVDF membrane materials under natural aging and accelerated aging

对6组自然老化下的PVDF膜材和1组人工加速老化试验下的Ferrari 1202T膜材的主要力学性能数据进行了汇总,包括单轴抗拉强度、断裂延伸率、撕裂强度以及单轴和双轴杨氏模量,在此基础上对经历了自然老化的第6组膜材补充了人工加速老化试验并测得其抗拉强度。通过对比第1,2组自然老化膜材的试验结果,研究了环境因素对PVDF膜材老化性能的影响;研究和对比了PVDF膜材在自然老化与人工加速老化试验下力学性能的变化规律,基于性能保持率的等效时间为表征指标,验证了互易定律的失效性。采用两种经典拟合方法估算PVDF膜材的使用寿命,结果表明PVDF膜材的寿命以等效时间表示为1860h,换算成自然老化时间后,第1,2,3,4,6组膜材的寿命分别为18年、20年、17年、19年和19年,最终为膜结构的理论分析、设计计算和寿命预测模型的建立积累了重要数据。

The main mechanical performance data of 6 groups of PVDF membrane materials under natural aging and 1 group of Ferrari 1202T membrane materials under artificial accelerated aging test were summarized,including uniaxial tensile strength,elongation at break,tearing strength and uniaxial and biaxial Young′s modulus.On this basis,the artificial accelerated aging test was added to the sixth group of PVDF membrane materials after natural aging,and the tensile strength was measured.By comparing the test results of the first and second groups of natural aging membrane materials,the influence of environmental factors on the aging performance of PVDF membrane materials was studied.The changes of mechanical properties of PVDF membrane materials under natural aging and artificial aging tests were compared.The equivalent time based on the performance retention rate is the characterization index,and the invalidity of the reciprocity law was verified.Two classical fitting methods were used to estimate the service life of membrane material.The results show that the service life of membrane material is expressed as 1860 hours in equivalent time.When converted to natural aging time,the service lives of groups 1,2,3,4 and 6 are 18 years,20 years,17 years,19 years and 19 years respectively.Finally,important data has been accumulated for the theoretical analysis,design calculation and life prediction model establishment of the membrane structure.