Hi Readers! We are continuing in the series of new science that we did in chemistry camp, talking today about how to create a polymer from milk.
The Experiment: Warm up whole milk, and then stir in vinegar to the milk. When a precipitate (solid) starts to form, filter out the solid using a cheesecloth or a coffee filter. Dry the solid by pressing it between two paper towels, and then shape the “polymer” into whatever kinds of creations you would like. Adding food coloring to this “polymer” can allow you to create all kinds of interesting things. After you are done shaping the polymer, let it dry in the air for several days until you have your own “polymer” creation!
The Science: Technically, you are not really creating a polymer here, although it is common to refer to this experiment by these terms. What is the actual experiment? It is an isolation of the casein protein from milk by adding an acid, vinegar, which causes the casein to precipitate in a globular form. This causes a polymer-like substance to come out of the milk. Does this work with other milks such as skim milk or 1% milk? Yes, sure, although they generally have lower protein contents and more water, so less casein polymer will come out of the solution. You cannot do this experiment with plant milk alternatives like cashew, almond, or soy milk, though, because those don’t have the casein protein to be isolated.
Want to read more about this experiment? Check out the links below:
Safety Concerns: Safety concerns here are pretty minimal (unlike our fire experiment from last week), which means it is safe for you to try this at home and share some pictures of your milk polymer results! Note that people with an allergy to milk are likely to be sensitive to touching casein (like one of the scientists-in-training at my house) and should probably wear gloves in that case.