Expandable Functional TFE Copolymer Fine Powder, the Expandable Functional Produdcts Obtained Therefrom and Reaction of the Expanded Products

A process for making an expanded functional TFE copolymer material comprising:

• a) emulsifying at least one functional comonomer having a functional group to form a functional comonomer emulsion comprising water, and a fluorosurfactant;
• b) providing at least a portion of the functional comonomer emulsion to the polymerization vessel;
• c) providing TFE to a polymerization vessel;
• d) polymerizing TFE and the at least one functional comonomer in an aqueous dispersion polymerization process;
• e) essentially completely consuming in the polymerization or removing the at least one functional comonomer prior to completion of the polymerization;
• f) continuing polymerization of the TFE after essentially completely consuming the at least one functional comonomer and collecting a dispersion of particles of a functional TFE copolymer having pendant functional groups,
• g) coagulating the dispersion of particles or fine powder of the functional TFE copolymer;
• h) washing and drying the coagulated particles or fine powder of the functional TFE copolymer;
• and
• i) processing by paste extrusion and expanding into a porous polymeric material having a microstructure of nodes interconnected to fibrils.