update: In order to make it easier to answer this question, use of "synthetic materials as a replacement for rubber circa 1969" in any aircraft might be good enough.
Michael Crichton's 1969 science fiction thriller The Andromeda Strain and the 1971 film of the same name ficticiously describe/depict a Phantom F-4 where a biological agent recovered from a satellite and subsequently mutated degrades and destroys rubber-like materials in the aircraft including the pilot's oxygen mask, and eventually the pilot as well.
In this clip from the film an expert at the site of the crash says:
There is no actual rubber on the phantom F-4 general. It’s all a synthetic plastic compound called “polychron”. It has some of the characteristics of human skin.
The spelling is in the computer-generated closed captions. I can find an insecticide Profenofos which is also called polycron, but nothing else.
Crichton is famous for meticulous technical research (generally) for his books, though they are still of course fiction.
Because of that, I'm wondering if the plot device of "polychron" replacing rubber in the F-4 has some basis in fact.
Question: Did the Phantom F-4 contain "polychron" or other synthetic materials as a replacement for rubber circa 1969?