全氟磺酸树脂的流变性能和挤出过程中的流动不稳定性研究

Study on Rheological Properties and Flow Instability of Perfluoresulfonic Acid Resin During Extrusion

为研究PFSA熔体的黏弹性和稳定流动区,通过旋转流变和毛细管流变仪分别研究了PFSA的动态流变性能和高速挤出过程的不稳定流动行为。结果表明:PFSA表现假塑性流体行为,复数黏度随着剪切速率的升高而下降,损耗因子(tanδ)随温度的升高而增加。在高速挤出过程中PFSA熔体在测试的速率范围内呈现稳定区、鲨鱼皮区,黏滑区和严重熔体破裂四个流动阶段。温度升高出现熔体破裂的临界剪切速率升高,且熔体的交换容量越低,出现熔体破裂的临界剪切速率和临界剪切应力越低。

The dynamic rheological properties of Perfluorinated Sulfonic-Acid resion(PFSA)were studied by rotational rheology meter.PFSA exhibited typical pseudoplastic fluid behavior and complex viscosity(η*)decreased as shear rate increased.The greater the loss factor(tanδ).The high shear unstable flow behavior of PFSA resin was studied by capillary rheometer,and the effects of temperature and exchange capacity on the flow behavior of PFSA melt were discussed.The results showed that the PFSA flow behavior experienced four flow stages:stable zone,sharkskin zone,stick-slip zone and severe melt fracture region.The critical shear rate of melt fracture increased with the increase of temperature,and the critical shear rate and the critical shear stress of PFSA melt fracture decreased with the decrease of ion exchange capacity.