First, I tested a movie from youtube to make bioplastics with corn starch (2 spoons), glycerol (1 spoon) and water (250ml).
I boiled it until i had a sticky mixture. Then I spread it over a baking sheet and let it dry. This was the result. An average firm translucent foil made of corn starch. afterwards I tested whether it was possible to seal the plastic together but without success, the plastic sticked but soon came loose.