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It being a plastic raises a few questions: - Is it petroleum-based? Looks like the answer is no. [1] - What's the durability? PVA seems to be very water-sol

by rdw 6y ago

It being a plastic raises a few questions: - 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 https://en.wikipedia.org/wiki/Polyvinyl_alcohol [2] https://www.cfsanappsexternal.fda.gov/scripts/fdcc/?set=GRASNotices&id=767 https://www.cfsanappsexternal.fda.gov/scripts/fdcc/?set=GRAS...

jws 6y ago
What's the durability? PVA seems to be very water-soluble 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.
bigbubba 6y ago
> Is it petroleum-based? Looks like the answer is no. [1] 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..)
- 3646urud 6y ago
  Honestly, being petroleum based would make me more likely to invest not less. Green energy is garbage unless you're either advantageously situated or enjoy rolling blackouts and meanwhile the developed world is going to fight the developing world mass adopting nuclear tech tooth and nail. So oil is going to be around awhile and by extension its presence is a good signal for supply chain reliability.
- Apofis 6y ago
  Can't you get ethylene from plants like corn?

by rdw 6y ago

jws 6y ago

What's the durability? PVA seems to be very water-soluble 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.

bigbubba 6y ago

> Is it petroleum-based? Looks like the answer is no. [1] 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..)

3646urud 6y ago
Honestly, being petroleum based would make me more likely to invest not less. Green energy is garbage unless you're either advantageously situated or enjoy rolling blackouts and meanwhile the developed world is going to fight the developing world mass adopting nuclear tech tooth and nail. So oil is going to be around awhile and by extension its presence is a good signal for supply chain reliability.
Apofis 6y ago
Can't you get ethylene from plants like corn?