Instructables
Picture of Easy Biodegradable Plastic
Now lots of products are made out of plastic. A lot of it is throw away and will stay in garbage dumps of thousands of years. Biodegradable plastic, unlike normal plastic made from petroleum, will decompose and become part of the soil. This Instructable will show you how one easy way to make some biodegradable plastic.
 
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Step 2: Proportions

The proportions to make the plastic are:

1 TBSP Corn Starch: 1.5 TBSP Water: 3-5 Drops Cooking Oil

Step 3: Preparations

Mix the ingredients together to form a milky looking liquid. Once you have done this it is ready to be microwaved.

Step 4: Microwaving

Put the mixture in the microwave and set the microwave on high for 25-30 seconds. The mixture should start to bubble and should become slightly transparent. Keep an eye on the mixture to make sure nothing goes wrong.

Step 5: Molding The Plastic

Picture of Molding The Plastic
When it looks slightly transparent, take it out. Let it cool a bit so you can handle it. Then knead the plastic until it is soft and can be molded like play-dough. Now you can mold it into whatever shape you want it to be. Once molded leave it for about 24 Hrs. for it to cure and become solid. It's best to keep the surface from drying out while it is curing. The image below is the plastic when shaped.

Step 6: Ideas

-You can add food coloring to give the biodegradable plastic some color.

-You can use it to make plant pots so you start the plants indoors and when they've grow you can put them in the ground.
Mr_make_a_lot5 months ago

sorry master dude your Easy Biodegradable Plastic in not working

Masterdude (author) 5 years ago
I'm going to try to post some new pictures.
Yes. It needs original pictures, especially of the final product.

i will soon upload them!

jc. berzuela8 months ago
Why cooking oil
tantan2731 year ago
let me ask ya.... we don't have a microwave here... so, is there another thing that can heat up this PLASTIC?

can we use STOVE?
I hope it will... :/
Masterdude (author)  tantan2731 year ago
Unfortunately I do not know. I assume that all that is needed is heat and that there aren't any microwave specific interactions happening. I think that it should work, maybe even better if a stove is used since you have greater control over the process and consistency.
loikkonen2 years ago
Hi, how strong is this? Can it bend? I'm guessing it's not waterproof. I'm going to need plastic for a project, and it should be strong and preferably non-bendable.
Masterdude (author)  loikkonen2 years ago
Ir's been a long time since I've made some, but as I remember it wasn't flexible and being a plastic I would think that it would be waterproof, but I am not sure.
jakobus92 years ago
microwave?
probable the stupidest question ever:
will just heating it up work just as well? or is there any microwave magic going on ? ;-)
Masterdude (author)  jakobus92 years ago
I haven't tried it by just warming up but I'd guess that all it needs is heat, not microwaves, to work.
PS1185 years ago
I'd like to know a little more of the chemistry. What exactly (chemically speaking) did we just make here? And what are its properties?
There is an entire website dedicated to answering questions about bioplastics, and especially for people interested in making it at home.

http://green-plastics.net

It has articles explaining the chemistry, as well as practical questions, and if you post a comment they often will create a post dedicated to answering your question.  It's had articles on everything from "why do some people say to use Vinegar in the bioplastic?" to "How can I make a bioplastic hard enough to make a toy sword?" (which is a funny one LOL).

Anyway, check it out, it'sa great resource.
I'm not totally sure, but I think it's some kind of starched-based structure. The water probably suspends the starch and the oil keeps it together while the water dries away, leaving an oil and starch-based plastic. LOL i reply two years after you posted the question
Ha ha. No problem. I had to scroll back up and look at what my question even was. :)
naveen_nk3 years ago
guys can u please tell me which cooking oil is best
Masterdude (author)  naveen_nk3 years ago
Well I don't know but the canola oil worked for me and I read that some others work as well. Probably any cooking oil will do.
I made it! I can't wait until it dries!
lemonie5 years ago
Can we see a picture of this stuff? L
Masterdude (author)  lemonie4 years ago
I just added this image. It is right after molding but before curing. I can't give images of it after curing because it fell apart because I didn't keep it moist enough. I'll try to get some better images another time.
IMG_0610.JPG
Yea, that look like the thing, I might try this (except I've got a lot of lead I'd like to use...)

L
drawe21 lemonie5 years ago
I made a batch with 1 cup cornstarch, 1 1/2 cups water, 1 teaspoon oil and it came out well. (cooked for 8 min in microwave) Looks a bit like semi clear mashed potato's (semi clear) My photos came out looking very bad. Sorry...
crearc5 years ago
I tried it. I thought it was really cool to make, but it ended up being pretty brittle. some portions held together nicely though. I like how it's a simple formula, but it still needs to be refined. I want to be able to pour it into a mold but it isn't liquidy enough after. I was wondering, can you put clay or playdough in the microwave? Thanks.
Masterdude (author)  crearc4 years ago
It doesn't seem to be liquid after microwaving and I suggest covering the plastic with a moist towel or such to keep it from drying out before finishing curing. the brittleness probably is because some of it dries up and that part contracts causing deformations which cause brittleness so the key to preventing it should be keeping it moist while curing.
i think this may be just what i'm looking for for my seed trays, now i need to still come up with the mold. i need the 20 row seed tray (front tray) any ideas on what to use as the mold? for that matter any mold for any cell pack, or small flower pot...
2655.jpg
Styrofoam. Just cut it to the inverse (opposite) Of what your trying to make and squish it into all the little holes.
edfel015 years ago
how long until this stuff deteriorates? and how strong is it and wat not but other then that nice simple plastic. Good Job
microman1715 years ago
I'm looking forward to trying this this afternoon. Does it melt again? This could be a super cheap thermoplastic. Polymorph anyone?
It doesn't melt or rehydrate (well, it soaks up water but you can't re-shape it). It has severe shrinkage-all that water you added? It evaporates to 'set'. It will burn...
strax5 years ago
i'm thinking plant pots. any ideas on molding these in mass and how long they last is appreciated. strax
i tried this, i think i put in too much oil, but mine was all sticky, maybe needed to knead it some more? really not alot to work with, i'm wanting to make around a 11"x13" seed tray, so how much u think i should try to mix up at one time.....gonna try again tomorrow tnx
S1L3N7 SWAT5 years ago
That looks cool. How long does this last until it completely deteriorates?
jtobako5 years ago
Final picture? I'd like to know what you thought about the shrinkage on drying cornstarch. I use a filler and get some nasty internal shrinkage.
Yes, I agree totally with you. That details are the most important part. Anyway, this seems a good recipe.