- Is it petroleum-based? Looks like the answer is no. [1]
- What's the durability? PVA seems to be very water-soluble [2]
- How's the scratch resistance? I wasn't able to find a source.
[1] https://en.wikipedia.org/wiki/Polyvinyl_alcohol
[2] https://www.cfsanappsexternal.fda.gov/scripts/fdcc/?set=GRAS...
In section 4 "Experimental Section", which is oddly behind section 3 "Conclusions", you will find that unless protected by a layer of paint, the material is severely weakened by humidity and subject to swelling and deformation when soaked with water.
Are you sure? From that link: "PVA is prepared by hydrolysis of polyvinyl acetate"
Follow that and you'll find: "Polyvinyl acetate is prepared by the polymerization of vinyl acetate monomer (free radical vinyl polymerization of the monomer vinyl acetate)."
Which leads to "The major industrial route involves the reaction of ethylene and acetic acid with oxygen in the presence of a palladium catalyst.[6]"
And finally: "Ethylene is produced by several methods in the petrochemical industry. A primary method is steam cracking (SC) where hydrocarbons and steam are heated to 750–950 °C."
PVA seems to be made from fossil fuels (oil, coal, or natural gas) when manufactured at industrial scale, though Wikipedia does a good job of obscuring this. The Wikipedia page mentions that North Korea produces it because it doesn't require oil but they make it with coal instead, which isn't mentioned on that page. The section on environmental considerations mentions only that it's nontoxic and biodegrades, nothing about where it comes from. (Do the fossil fuel / chemical industries have a history of misleading the public? Hmm..)