Different types of starch can be experimented with! Try potato starch, corn starch (pictured here), and tapioca starch!
- Prepare work area (see previous protocols)
- Measure and mix together 50g glycerol, 400ml water, 30g starch, 60ml vinegar in a pot (feel free to try out different ratios - less starch makes the solution less thick and less glycerol makes it less flexible
- Cook over medium heat and sitr for 10 minutes or longer - continue to heat even after solution is viscous, after 10 minutes bring it down to a low heat
- Remove from heat for 30-60 seconds and get ready to spoon out almost immediately
- Add pigment quickly during short cooling time
- Spoon thin layer of mixture into frame to create a thin, even surface.
- Cut the edge of the starch bioplastic from mold with exacto blade after 24 hours
- Sit and let dry for up to 3 days - the thicker the layer the more the starch bioplastic is prone to crack, so create as thin of a layer as possible when intially pouring and spreading.
Starch is a biopolymer of amylose and amylopectin polymers consisting of glucose (sugar monomers). Starch granules are tough to break down and don't dissolve on their ow, but when heated for long periods, their intermolecular bonds start to break down, and vinegar as weak acid helps break down the amylopectin polymer chains.
Starch is one of the trickier bioplastics to make. If laid too thick, the bioplastic will crack as it shrinks over time. There will be shrinkage no matter the case, but a thinner layer allows for the best results. Spread the solution evenly and thinly after heating. Make sure to cut and free the edges of the starch bioplastic from a wooden mold after 24 hours so the center doesn't crack or break.