高温气相环境对PTFE/PPS复合膜性能影响

Effect of high temperature gas environment on the properties of PTFE/PPS composite membrane

聚四氟乙烯/聚苯硫醚(PTFE/PPS)复合膜是除尘领域运用最广泛的复合膜之一,其使用寿命受烟气参数影响显著.本研究针对PTFE/PPS复合膜的实际应用条件,通过高温气相腐蚀对PTFE/PPS复合膜进行抗老化性能测试,在120~240℃温度范围内,以空气为气氛,研究了氧存在条件对PTFE/PPS复合膜的耐老化性能影响;基于腐蚀气体(SO_(2))浓度、腐蚀温度与时间,建立了膜材料拉伸强度的响应曲面模型.研究结果表明,氧气使复合膜中的PPS支撑体产生氧化交联反应使其纬向断裂强力有所上升,200℃老化48 h后达到最大值2132.2 N;由响应面可知,增加温度与SO_(2)浓度对PTFE/PPS复合膜的断裂拉伸性能的衰减影响显著,当温度从180℃增加到240℃时,其经向断裂强力衰减至初始值的90.97%;当SO_(2)浓度由2096 mg/m^(3)增加至2620 mg/m^(3)时,经向断裂强力衰减至初始值的98.12%.该工作为复合膜在烟气净化中的应用条件优化提供了依据.

PTFE/PPS composite membrane is one of the most widely used composite membranes in the field of low and medium temperature dust removal,and its service life is significantly affected by flue gas conditions.According to the application environment of PTFE/PPS composite membrane,the anti-aging performance of the membrane was tested by high temperature gas corrosion.The effect of oxygen on the aging resistance of PTFE/PPS composite membrane was studied,and the response surface of tensile strength of the membrane was established based on the SO_(2)concentration,corrosion temperature and time.The results showed that the zonal fracture strength of the PPS support increased due to the oxidative cross-linking reaction in oxygen atmosphere,and reached the maximum value of 2132.2 N after 48 h of 200℃aging.From the response surface,increasing the corrosion temperature and SO_(2)concentration has a significant effect on the fracture tensile properties of PTFE/PPS composite membrane.When the temperature was increased from 180℃to 240℃,the meridional fracture strength decreased to 90.97%of the original;When the SO_(2)concentration was increased from 2096 mg/m^(3) to 2620 mg/m^(3),the warp breaking strength attenuated to 98.12%of the original.The results suggest that PTFE/PPS composite membrane has good stability in the field of high temperature flue gas purification.