Hello YouTube! Today we're going to learn about bioplastics. How to make some and what they're all about. For this experiment you're going to need 9.5 grams of cornstarch, 60 milliliters of water, 5 milliliters of glycerin, and 5 milliliters of 5% acetic acid in water or vinegar. You're also going to need a hot plate, a beaker, a glass stirring rod, and either tin foil, wax paper, parchment paper, or a silicone baking sheet. Start by charging in your 60 milliliters of distilled water, then then charging your cornstarch. Start stirring and agitating until you get a even homogenous suspension. Charging your glycerin, it's pretty thick so make sure it all gets in there and mix thoroughly. Then finally you can add in your vinegar and again mix it all up. Now turn on your heat and start stirring like crazy. Now what's the chemistry that's actually happening inside that beaker? Well, starches are polysaccharides or large branched polymer chains consisting of sugar molecules. As you heat the mixture, the acetic acid hydrolyzes or breaks the bonds between the branches and this leaves you with long linear chains of polysaccharides or sugars. Ordinarily these linear chains are fairly stiff, but because we added glycerin, this acts as a plasticizer enabling the plastic to be somewhat flexible and not brittle. Now after you heat for a while you end up with a thick viscous goo. If you heat for a little longer, turns a little bit clear like that. Take the mixture and pour it out onto your sheet, tin foil or silicone baking sheet, wax paper if you don't have it either of those and just spread it out. If you're making this for fun, you don't need to be too careful about thickness control. As you can see here after it's cooled down a little bit, it's a thick opaque layer of almost like a gelatin on the foil. Even as hard as you try, the thickness isn't very even. He has lots of little bumps. But after a week of drying, you end up with a plastic film like this. This plastic film is very thin. Thickness is fairly even despite the unevenness in the molding process. But it's quite strong and stretch resistant, tear resistant. Most of the tears you can see here from actually trying to remove it from the aluminum foil, hence why recommend a silicone baking sheet. But it's tear resistant and really can't break it too easily. Now, what are bioplastics good for? Well, to start off, you have to think about what a bioplastic is. Bioplastic by definition is a plastic or polymer derived from a biological source that's renewable versus a petroleum based source that is non-renewable. Now, if you think about it, some good uses for bioplastics are disposable plastic things like drinking cups, utensils, and plastic wrapping films. You've got a polystyrene cup on the left and a corn based cup on the right. They look exactly the same and they function the same. But one will stay in the landfill for 20 or 30 years, probably much longer. And the other one will degrade within a few years. Now, on the underside of these cups, you have a recycling symbol. This one has a polystyrene symbol. But this other cup is classified as other. This cup is made out of polylactic acid or PLA. It's a thermoplastic, so it's only good for cold drinks and it's considered compostable. But what's the difference between compostable and biodegradable? Well, the European Union considers compostable plastics to be biodegradable films no more than 20 micrometers thick. That's pretty thin. You can't build thick sturdy objects out of them. And in terms of how well you can degrade these plastics, it's not very easy. They're surprisingly durable. Here we have a couple clippings from one of those degradable plastic cups stirring in hot sodium hydroxide, specifically two molar sodium hydroxide, pH 14, at about 90 degrees Celsius for about five hours. And that didn't even do anything to it. And then I gave up heating and left it stirring for about a week. And even after a week of stirring, it still looks exactly the same. There's basically no degradation other than a little bit of warping and swelling of the plastic. Again, these cups are rated to degrade over two to three years. So I hope you enjoyed this video and learned a little bit about bioplastics. The take-home message here is that bioplastics aren't a fix-all tool to a problem, a problem that is waste. There's cliches that sounds, reduce reuse and recycle are still very applicable because this stuff still takes up landfill space, it still takes time to degrade, and it's still energy and material wasted. Well, if you enjoyed this video, please like, subscribe and comment. Thanks for watching.