What about fluoropolymer or Kapton ? They are technically better stuff. Fluropolymer is extremelly advanced product , it does not harm with chemicals or uv and tear resistant. If Dupont turns you back , you can ask the supplier about product range they sell. Polyester is weak to chemicals and uv , high heat and tear and cheap stuff. Fluoropolymer films are used as satellite wraps at space and non oil changing for years automobile engines. There is no way to destroy it.