When you need heat resistance and extra adhesive on the inside for extended holding power, than High Temperature Lined Teflon PTFE from BuyHeatShrink is what you're looking for. Since the adhesive is already there, you don't have to bother with extra Hot Melt Tape or the like.
Available in a 2:1 shrink ratio and meeting or exceeding the most stringent commercial and military standards, this is the only high temperature adhesive-lined heat shrink tubing on the market.
High heat PTFE has a continuous operating temperature of -454° to 500°F (-270 to 260°C) and a very high continuous use temperature of 500°F (-270 to 260°C) as well. It resists all but the harshest chemicals known, has a low coefficient of friction and good dielectric strength. Its Limiting Oxygen Index is 95%, which means that it is incredibly flame resistant.
It's available in both standard and lightweight wall thickness.
A: Molten alkali metals, fluorine gas at high temperatures, and chlorine trifluoride. Note that two of these contain fluorine, which is the element that makes PTFE so resistant to high temperature and corrosive chemicals in the first place.
Fluorine and carbon bond very tightly, so it takes a lot to tear them apart, which is why fluorine-containing elements are so effective at breaking the bond. Meanwhile, alkali metals (things like lithium, sodium, potassium, and so on) are highly reactive when not bonded to other elements and in their molten form are generally not bonded.
A: Teflon and PTFE can't. Because of the strength of the carbon-fluorine bond, it's very difficult for anything to get a chemical or mechanical grip on it. This is why it works so-well in no-stick cookware. It even makes insects slip, so is often used in entomological settings to keep bugs from being able to climb out of their containments.
The part with the low coefficient of friction is the adhesive inside, which has a melting temperature lower than the shrink temperature of the tubing. As one contracts and the other liquifies, the adhesive is compressed, creating a very tight, waterproof seal that keeps the tubing bonded to the cables or wires inside.