PTFE Teflon Seals satisfy the requirement for low coefficients of friction, certain temperature range, the need to seal a corrosive acid and so on. These are the typical sorts of elements that tell you that an elastomeric seal likely won't fit your application. PTFE seals are often the only answer. Perhaps something as simple as a PTFE O-Ring, or a PTFE compound cap to protect the elastomer will do. Or on the other hand, spring energized PTFE U-Cups, like those in our Polyspring line might be required. Many of the potential solutions can be found in our Polyking catalog.