Thermoplastic Starch – Potato Plastic
Objective: to learn how to make a plastic film from potato starch
Introduction: Biodegradable plastics can be derived from many starch-based materials. In this lab, we
will make a plastic film from potato starch and test its properties. Potato starch is a polymer made of
long chains of glucose units joined together. Specifically, it contains two polymers:
1. Amylopectin – a highly branched polymer of glucose units
2. Amylose – a straight chain of glucose units
The amylopectin prevents the starch from becoming plastic-like. In this lab, acetic acid is used to break
down the amylopectin and change the structure and properties of the polymer.
We will make two different batches of the potato plastic. One batch will contain glycerin, which acts as a
plasticizer, and in the other batch the glycerin will be left out.
Pictures