A New Development In Base-Resistant Fluoroelastomers 2002-01-0636
FEPM Dipolymers of tetrafluoroethylene (TFE) and propylene (P) are known to exhibit excellent resistance to nucleophilic attack by basic chemicals. FEPM polymers, however, are difficult to process, and exhibit relatively poor resistance to many hydrocarbon lubricants, particularly compared to conventional fluoroelastomers (FKM): e.g., copolymers of vinylidene fluoride (VF2), hexafluoropropylene (HFP), and, incorporated in some FKM types, tetrafluoroethylene (TFE). Terpolymers of TFE, propylene, and VF2 are available which contain higher levels of fluorine than FEPM dipolymers, due to the incorporation of VF2 monomer, and these polymers exhibit some improvement in resistance to hydrocarbon fluids. TFE/P/VF2 terpolymers, however, are not as resistant to base attack as dipolymers of TFE/P.
This paper introduces a new polymer that exhibits excellent processing characteristics, including mold release. This new polymer provides improved resistance to hydrocarbon fluids, compared to currently available TFE/Propylene copolymers, and in addition, the new polymer also exhibits excellent resistance to base attack, equivalent to that provided for by TFE/P dipolymers.