These are polyolefins. Think of them as ultra-high molecular weight wax.

Wiki: polyolefins for a quick primer.

Go fish! They are insoluble in almost everything. Tons of chemical laboratory containers are made from PE. Machines that etch metal with acids are made from PP.

Even if you could produce a 1-5 micron film, you would never be able to peel it off the disk.

You might try getting the thinnest PE film available and try to heat and stretch it.

Good luck.

You could try blow molding polythene or polypropylene sheet. It will stretch considerably.

I believe blown film is available down to about 50um in polythene. This is about 10x what you are after. It should be possible, with care, to take it down the rest.

Have fun.

While polyethylene or polypropylene are not likely to be possible in this situation, you could contact Sartomer at www.sartomer.com for specialty UV curing monomers that can make a coating that might do the job for you. Using acrylic terminated waxy oligomers (partially polymerized monomers) is frequently done in industry. While waxy monomers are not polyethylene, they might be the closest you can find easily.

The coatings are called "hardcoat" and there are also companies that sell UV curing hardcoat formulations ready to use, which you can locate on Google. Electronics, flooring, furniture, and window film industries among others are big users of these materials.

The electronic industry uses "paralyene" coating technology, which you can investigate on Wikipedia.

Good luck!