Fluoropolymer materials containing tetrafluoroethylene monomers, such as
PTFE, are significantly swollen by supercritical carbon dioxide at high
temperatures and pressures. The swollen fluoropolymer is processable by
molding, extrusion, and other techniques. In addition, the fluoropolymer
may be sintered at significantly lower temperatures compared to a
nonswollen fluoropolymer material. The melting temperature of fluorinated
polymers containing tetrafluoroethylene and triflouroethylene monomers
which are swollen with supercritical carbon dioxide is significantly
reduced, thereby permitting manufacturing operations such as extruding
and molding to be performed at lower temperatures and with reduced risk
of decomposition.