Fluoropolymer-carbon dioxide compositions and methods of processing fluoropolymers

Abstract

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.

1 . A swollen polytetrafluoroethylene material which includes at least 10% by weight carbon dioxide.  
     
     
         2 . The swollen polytetrafluoroethylene material of  claim 1  which includes at least 25% by weight carbon dioxide.  
     
     
         3 . The swollen polytetrafluoroethylene material of  claim 1  which includes at least 40% by weight carbon dioxide.  
     
     
         4 . A swollen fluorinated polymer material having tetrafluorethylene monomers in the chemical backbone which includes greater than 10% by weight carbon dioxide.  
     
     
         5 . The swollen fluorinated polymer material having tetrafluoroethylene monomers in the chemical backbone of  claim 4  which includes greater than 25% by weight carbon dioxide.  
     
     
         6 . The swollen fluorinated polymer material having tetrafluoroethylene monomers in the chemical backbone of  claim 5  which includes greater than 40% be weight carbon dioxide.  
     
     
         7 - 52 . (canceled)