A seal comprising a jacket comprising an annular body defining a central axis and a recess extending into the annular body concentric to the central axis, wherein the jacket comprises at least 30 wt % of a PTFE and at least 10 wt % of a filler material, and wherein the filler material comprises a boron-containing material, a nitrogen-containing material, a titanium-containing material, a silicon-containing material, a carbon fiber, a glass fiber, or a combination thereof; and an energizing element disposed in the recess.