Polyethersulfone
From Tardis Wiki, the free Doctor Who reference
PES, acronym for polyethersulfone, was a petroleum-based plastic. Its appeareance was "slightly amber, almost opaque". It was produced at least on the planet Lakertya. Contrarily to PHB, it was not biodegradable.
The First Rani employed it as a heat conducting material in the assembly of a Time Manipulator. (TV: Time and the Rani)
