EZ-make bioplastics for greenhouse windows?

I think the search feature must be haunted because I couldn't find anything about making bioplastics at home, but if wikihow is to be believed you can cook your own at home with cornstarch and vinegar. I know there's good arguments against a greenhouse entirely, but as a freaky-cheap thing to help with warming over the winter it seems ok.  And if you can save money on plastic ($72 for 10 clear bioplastic garbage bags from If You Care? I care, but not that much!) then that makes a crappy greenhouse buildable.

So, when searching for cheap bioplastics I found, thanks to autocomplete, "bioplastic recipe"!!!

???  

What?

This is what it says:

Gather the necessary materials. To make this type of bioplastic, you will need cornstarch (potato starch also works as an alternative), distilled water, glycerol, white vinegar, a stove, a saucepan, a silicone spatula, and food coloring (if desired). These items should be readily available at the grocery store or online. Glycerol is also called glycerine, so try searching for that if you’re having trouble finding glycerol. The following amounts of each ingredient are needed to make the bioplastic:
10ml distilled water
0.5-1.5g glycerol
1.5g cornstarch/potato starch
1ml of white vinegar
1-2 drops food coloring
Adult supervision is recommended


I believe I can get all these ingredients except maybe "adult supervision "...

Anyone doing this already?

Is it translucent enough?

Is it strong enough for winds?

What about for wofati pond liner uses?

Any toxic downsides I'm not seeing?

Worth looking into!
Hard to imagine this would be waterproof.
Hard to imagine making it into a sheet.

I've been wanting to cover window screen in translucent wax  for a seasonal green house wall.
This stuff might work for that or better.

Cellophane is a clear film, biodegradable,  made from trees...
in very resource intensive process, using toxic carbon disulfide...

Greased paper and cloth has been suggested in the past.

Thanks William,

I think this is getting way more complicated than I'd hoped.

Glycerine is not sold in grocery stores, and even though everything is both a grocery store and a pharmacy nowadays, the groceryarmacy didn't have it, so I'll have to get more later.  Sucrose did not work so well (the stuff didn't quite boil but got really thick before it could boil and really become transparent).

It didn't spread very thin on the sheet, since it hadnt' gotten to the really labile texture.  I'm thinking the glycerine vs. fructose-glucose mixture was what made the difference.

I would very much like to see the wiki how article improved.

Web searches have not turend up anything useful about quantities for substituting sucrose for glycerine or groceryarmacies for pharmaoceries.  They reveal that I was too lazy to walk another .2 miles back to the latter since I was just there, and the recipe lied to me twice.

A youtube video clearly shows the stuff getting transparent, not just translucent, which is more like what I want, and more of a positive sign.

On the plus side, the fact that so many of the things on the internet seem to be focused on how to make a plastic different from the one I want to make gives me hope that I just need to swing by the pharmaocery and get some glycerine.  

Also, the quantities needed to make a large sheet of plastic seem pretty miniscule.  

I'm going to give it one more try...and also see what happens to my "plastic" when it dries on the surfaces I left it on.  Maybe I'll try it with fudge sauce after.

The bioplastics industry is pursuing completely different aims.

I am pretty sure that bio-bags (the common "plant-derived" bag around here) would do for a season on a crummy greenhouse.  it seems it only breaks down when there's microbial presence (so, proximity to dirt).   Sunlight alone wouldn't degrade it too much.  It would last you about a year.

I like the idea of home-making a batch of plastic once a year.  That is more permanent than using something truly unsustainable (like mined fossil fuels) to last 5 years...

Maybe this idea is more of a transitional idea.

Another design idea would be to get a whole bunch of glass bottles and make a wall of bottles--1,000 bottles of air on the wall--rather than plastic bottles.  Or just use plastic ones if it's temporary anyway.  

I like having manay different ways of skinning a cat for this, and welcome more ideas.

The cloth idea sounds good too, I don't know enough about it and don't really have them.

Oh, one other idea that came to mind was just a black sheet/panel of wood--the heat just has to soak in, the light doesn't.  If the wood is thin enough not to be insulating much then it will absorb the heat.  Solar panels get notoriously hot on the bottom, I'm told, because they are not mirrors and don't reflect the sun radiation but absorb much of it.  

So maybe a black-roofed Oehyler greenhouse with a cold sink and black planks over the top instead of plastic or glass or fiberglass would make a super-cheap, slightly warming thing to stick on the south side of one's shelter.

Got glycerine.  Not a gifted plastic-maker.  I thought maybe this was my calling in life, but alas.  We'll see in 2 days if it actually polymerized.

But there are some good examples on youtube that look convincing, and it does feel empowering to know we can make plastic.  And choose and source the ingredients.

Corn starch--easy enough to grow that yourself
sugar--can be derived from sugar cane or beets, right?  I don't know how pure it would need to be.
vinegar--wheat, ferment grain alcohol

I'm also wondering about glass making now...

I know milk plastics used to be a thing before petroleum based plastics were popularized. Might be a lot easier to source waste milk from dairy farms instead of making glycerin. It is pretty much the same recipe but with whole milk instead of glycerin.

Although probably will loose the transparency.

T Simpson wrote:I know milk plastics used to be a thing before petroleum based plastics were popularized. Might be a lot easier to source waste milk from dairy farms instead of making glycerin. It is pretty much the same recipe but with whole milk instead of glycerin.

Although probably will loose the transparency.

The story checks out.  Used to make buttons, even!  This looks like a winner for making flower pots and such.

However, hard to tell from pictures I see if it's transparent enough for a greenhouse.  Most of the search results show plastic for milk jugs, not milk-plastic.

The recipe they give is just milk heated to 120 F and then add vinegar.  It curdles, you just use the curds and shape them, then let them dry.

If it makes buttons, is fairly waterproof, then I think it would make a plant pot that would last for a season for urban situations to do with less plastics and breakdown to microplastics.

Anyone know under what conditions this biodegrades?

https://www.britannica.com/science/casein  some more info on uses of this.  some applications include added formaldehyde, not so permy.  But it says it is not soluble with many organic solvents.  

I think glycerine is a byproduct of making biodiesel.