Week 7: Bioplastics
We were tasked with making our own bioplastics. First we had to experiment with different ingredients. We were given some ingredients like glycerine, agar and gelatine, but also we were challenged to add our own ingredients to see what would happen. Lastly, a bioplastic cook book was given to us to get us started. I chose to recreate the Agar Agar recipe from the cook, but I added red berry juice to give the plastic a red color.
Making this bioplastic was relatively easy. Basically all you needed was glycerine, agar and water. The red berry juice was added by my own choice. The amount of agar and water you had to add was constant (1.6 grams and 40 ml respectively), but the amount of glycerine you add would influence how flexible or brittle the bioplastic would be. The maximum amount you could add according to the recipe was 5.4 g. This would make the bioplastic the most flexible it could be. I was a fan of this idea so I chose to add 5.4 grams of glycerine. The amount of red berry juice I added was 20 ml. I wouldn't know what the effect of the red berry juice would be, all I knew for sure was that the color would change. 20 ml seemed like a safe amount to add. I threw everything in a pot and started cooking it. Having a fairly modern hot plate, it was able to cook very quickly. Once there was a lot of froth, I would remove the pan from the hot plate and check how viscous it was.
Once I was ready to pour the plastic into the mold I had created in week 5, I tried to pour it into a small squeeze bottle so I could squeeze it into the mold with precision. When it was in the small bottle, however, it had already hardened and was therefor stuck in the bottle. I had to remove it with a small knife. All the bits are now collected in a small petri dish, as shown below:
I wasn't satisfied at all. Not only did I not use my mold, the material was way too flexible. Not a lot of force was required to pull it apart however. I could not think of any useful purpose for this bioplastic and so I wanted to try again. I cleaned the pot (a challenge in and of itself) and started with pretty much the same recipe. I wanted it to be more brittle. I decided to reduce the amount of glycerine to two grams. This would put it right between brittle and flexible. The amount of agar and water would remain the same. I added a little more red berry juice (30 ml) in the hope it would give the bioplastic a more red colour than before. Upon cooking the pot and removing the pot from the hot plate (the same way I did before), I noticed there was a lot more bioplastic in my pot. This was of course thanks to the increased amount of red berry juice (which also contains water). It hardened a lot less quickly than before. This gave me enough time to ease the bioplastic into my mold and two petri dishes (that's how much I had).
The next day I went to look at my bioplastic. It had hardened quite good. Unfortunately the bioplastic was stuck to the petri dishes and even to my mold. I couldn't remove it without damaging the form. One of the petri dishes even broke while I was trying to remove the bioplastic from it. Nevertheless, the plastic looked good.
However, I was not pleased with the way the bioplastic turned out to be. It was way to fragile and I couldn't find a good use for it. That's why I decided to make a new bioplastic with a new recipe. Instead of making the Agar Agar bioplastic again, I wanted to make the Gelatine Animal Based bioplastic. I did use red berry juice again, because I like the colour red. For this recipe, I needed 60 ml of water, 12 grams of gelatine and, just like the previous recipe, a certain amount of glycerine, depending on how brittle or flexible you want the material to be. I chose for 7.2 grams of glycerine, because I'm more of a fan of flexible plastics. The process of making it was essentially the same. I threw everything in a pot and cooked it. This time I waited a bit longer to pour the liquid in a petri dish. I wanted the liquid to be a bit more thick (like the recipe suggests). I thought this would make the end result a bit less fragile. When I poured the liquid in a petri dish and waited for 24 hours, the result was pretty cool!
I immediately noticed that this bioplastic looked and felt a lot better than the last one. I had to use the toolkit on myself, because I couldn't get a friend to visit me. I didn't think this would pose as much of a problem, because the results would be the same.
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