Indeed impressive, although I consider the fact of using a temperature well below minus 200 degrees centigrades a sort-of-a-cheat. Heat the substance to room temperatures and it will most likely dissociate into ethyne and krypton again.
In any case, teflon is so resillient because of the way the fluorine atoms shield the carbon backbone. It would make little sense to replace the fluorine by krypton, let alone account for the fact that since krypton atoms are far larger than fluorine ones there simply is no room to do the replacement. I'm not sure what the material properties of a hypothetical kryptonised teflon would be like: ordinary teflon is difficult enough to handle as it is. It doesn't stick to anything---ever wonder how you manage to create a non-stick frying pan when the teflon won't stick to the metal it is supposed to protect?---and creeps like crazy when subjected to mechanical stress. Not a fun material to work with.
