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plastic too brittle

by Melissa

 

Hi
so i’ve tried making some starch based bioplastic for my science project but the thing is they are really brittle. The ones i made broke into pieces. So do i add more glycerol or should i add more starch?

Comments (2)

  1. Green Plastics says:

    The general rule of thumb is that to make a plastic more bendable or flexible you add more plasticizer (in this case, glycerol), whereas when you want to make it harder or stronger you add more polymer (in this case, starch).

    So I would try adding more glycerol. Is this for a film, or a thicker shape that you are pouring into a mold? I am asking, because if you are doing a thicker shape you may want to also consider using gelatin instead of starch as your polymer. However, if you are doing a sheet / film, starch should be fine.

    Happy experimenting!

    • Jamont says:

      “if you are doing a thicker shape you may want to also consider using gelatin instead of starch as your polymer. However, if you are doing a sheet / film, starch should be fine.”

      Why is gelatin better than starch for a thicker shape?

      When replacing starch with gelatin in a recipe, does one need also to change the other compounds and/or quantities or is it just a one for one switch between starch and gelatin?

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