Chemical reactions are carried out with molten fluoropolymer, most
conveniently in an extruder, wherein the reaction zone in the extruder is
isolated from the melting zone, and the molten fluoropolymer is subdivided
in the reaction zone sufficiently that contact and reaction between the
reactant and the molten fluoropolymer in the reaction zone is essentially
free of mass transfer limitation, followed by devolatilization in
isolation from the reaction zone, and cooling the devolatilized
fluoropolymer.
