It's called plastic money by the way, not polymer money.
https://en.wikipedia.org/wiki/Polymer_banknote
If you go to a country where they use these, they call them polymer notes.
They are made from a polymer and people that use them call them polymer notes. That's a decent amount of evidence compared to your no evidence.
https://www.youtube.com/watch?v=pJTLCmIW1rA
https://www.youtube.com/watch?v=7BD1xX7c1Jg
https://www.youtube.com/results?search_query=polymer+banknot...
https://www.youtube.com/watch?v=wNKVz933uFw
Polymer cups are also made from synthetic polymers like polypropylene. So are polymer knives and polymer forks.
I don't know what else to tell you. You said it's not called polymer money, I showed you a lot of evidence that it is.
https://en.wikipedia.org/wiki/Polymer_banknote