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What kind of glycerin?

by Green Plastics


sSyreNe21 asks in a comment on our YouTube Video:

what kind of glycerin is that?
crude glycerin?…pls reply..anyone..
im begging u!!!

Reply from Green Plastics:

Glyercin (also called glycerol) is something you should be able to get at drugstores, or even online (use google to search for “buy glycerin” and you should get a lot of hits).  Glycerol is produced by the fermentation of sugar, or from vegetable and animal oils and fats, as a by-product of the manufacture of soaps and fatty acids.

The purpose of glycerin in the bioplastic recipe is that it acts as a plasticizer.  If you are a student, you may have access to a wider range of supplies through school.  If you do, you might want to get you hands on sorbitol, which also works as a plasticizer.

Glycerin and other small molecules, like sorbitol, increase the plasticity of cast films and sheets.  You can add them to some form of polymer — in the case of the video, use plain starch like cornstarch.

To make bioplastic, you always want at least one polymer and at least one plasticizer, but remember you can play around with different amounts of each–and when you have access to more than one type of polymer or plasticizer, you can try them in different combinations, as well.

Experiment until you get it right: the more plasticizer you use, the more flexible the end result will be; but use too much, and the end result will be tacky and will never dry.

Comment here if you have more questions, and happy experimenting!

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