Science Club - Making Plastic from Milk

Have you ever heard that plastic can be made out of milk? You may be surprised to learn that from the early 1900s until about 1945, milk was commonly used to make many different plastic ornaments, including buttons, beads and other jewellery etc.  Milk plastic (usually called casein plastic) was even used to make jewellery for Queen Mary of England! In science club last Wednesday, students got to make their own casein plastic out of hot milk and vinegar.

Future scientist noticed that, when you add the hot milk to the vinegar, small, white chunks should have become visible in the mixture. This is because adding an acid, such as vinegar, to the milk changes the pH of the milk and makes the casein molecules unfold and reorganize into a long chain, curdling the milk. Students then dried the curds and then knead into a ball and used it as casein plastic, which they got to mold and decorate!