Larry Y. Yen

Formation of microporous Teflon® PFA membranes via thermally induced phase separation

Poly(tetrafluoroethylene-co-perfluoro-(propyl vinyl ether)) (Teflon® PFA) membranes of a variety of structures have been produced through thermally induced phase separation of Teflon® PFA-chlorotrifluoroethylene melt-blends of different compositions. A phase diagram of the two component system was constructed, and electron microscopy was used to characterize the structures of membranes produced. The morphological characteristics of the Teflon® PFA membranes have been explained on the basis of equilibrium driving forces for liquid-liquid and solid-liquid phase separations.