Is there any way to preserve those synthetic materials and gain a longer shelf life (eg. 15+ years)? Eg. Heat sealed foil bags with excess air removed, or even filled with nitrogen? The idea is to buy several spare consumables when you first purchase the equipment, and break them out at regular intervals.

I have the same problem with vulcanized coatings that go sticky after several years (looking at you, 3D Connexion SpaceMouse, Saitek X52, etc).