全氟磺酸离子交换树脂挤出流延薄膜加工性能研究

Research on Fabricating and Processing Performance of Perfluorosulfonate Ion Exchange Membrane by Melt Casting Technology

选取3种不同的离子交换容量（IEC）的氟型全氟磺酸离子交换树脂（PFSR），采用熔融流延挤出方法来制备不同IEC值的离子交换薄膜。分别利用热失重分析（TGA）、熔体流动速率仪、毛细管流变仪、哈克扭矩流变仪、X射线衍射（XRD）对3种树脂的熔融加工稳定性、熔体流变性能及挤出树脂的结晶性能进行了全面的分析研究。结果表明，在380℃以下，3种树脂的静态稳定性都很好，但当温度升高，静态稳定性随树脂IEC的升高而下降。低剪切速率下，PFSR熔融温度随IEC的升高而明显降低。PFSR树脂为剪切变稀型非牛顿流体，其表观黏度对加工剪切速率敏感；PFSR树脂在高剪切速率下的动态热稳定性能明显下降，当达到240℃以上，树脂中会出现微小气泡，其加工和动态热稳定温度随1EC值的降低而增加。另外，PFSR树脂为一种低结晶型聚合物，其结晶能力主要受其IEC值影响，并随其增加而下降。

Three kinds of perfluorosulfonyl fluoride resins （PFSR） with different IEC values were chosen to be candidates for preparing the perfluorosulfonate fluoride ion-exchange membrane （PFSIEM）. Melt processing stability, melt rheology and crystallinity of the PFSR were studied by means of TGA, MFI, capillarity rheometer, Hakke torque and XRD. Laboratory tests showed that the static thermal stability of three kinds of PFSR was perfect under 380 ℃, but it decreased with rise of IEC values when persistent overheating. At a low rate of shear, the melting temperature of PFSR decreased with the increase of IEC. The rheology testing showed that PFSR was shear thinned fluid and its apparent viscosity was sensitive to shear rate. Dynamic thermal stability degraded distinctly under high shear rate. And tiny bubbles would appear when it arrived at 240℃. Its dynamic thermal stability and process ability increased with the decrease of IEC values. XRD tests showed that PFSR was a kind of low crtstalline polymer and the degree of crystallization primary influenced by IEC values and decrease with its increase.