This Friday (July 9th), we’ll explore the chemistry of milk plastic (or casein plastic) in our new kids video series, Summer School with Live Science.
In this week’s article, Live Science producer Diana Whitcroft will show you how to use milk and vinegar to make a biodegradable plastic called casein plastic. She makes jewelry in this tutorial, but her family is encouraged to make ornaments, souvenirs, ornaments, and anything else she likes.
Every Friday at 3:00 pm EDT (12:00 pm PDT), Diana hosts a summer school with live science. Live Science Facebook, YouTube And twitter page.Every week, the series explores different areas of stem (Science, Technology, Engineering, Mathematics) Through simple hands-on experiments that you and your child can follow together at home.
Disclaimer: All scientific experiments, recipes, and methods are highly recommended to be tried only under adult supervision. Adults need to handle or help with potentially harmful equipment and ingredients. Be sure to wash your hands thoroughly after conducting the experiment. Avoid contact with your face or eyes when conducting experiments, and wear eyeglasses or protective goggles if possible. Do not take any ingredients during or after this experiment.
Milk plastic: material
Age range: 4-10 years
- 1 cup of whole milk
- 4 tbsp.White vinegar
- Small pot
- 1 large mug
- 3-4 paper towels
- Food coloring, beads, glitter (optional)
- Cookie cutter (optional)
Step 1: Select a design
Diana’s tutorial will show you how to make a ring from casein. However, you and your child are encouraged to make the ornaments you want, such as ornaments and souvenirs. Double the recipe to create a larger object. Let’s decorate beads and glitter!
Step 2: Make casein plastic
Warm the milk in a small saucepan. Do not bring to a boil. While waiting for the milk to heat up, add the vinegar to a large mug. If you want to double the recipe, consider upgrading from a mug to a mixing bowl. When the milk is just starting to foam, remove it from the heat and add it to a mug of vinegar. You will soon notice a lump, but allow the mug to cool for 3-5 minutes before handling.
Step 3: Mold the object
With a spoon, do your best to separate the milk solids from the liquid and transfer them to a paper towel. Knead for about 1 minute before adding any color or decoration. Continue to knead the dough, gently pressing it against a paper towel to get as much liquid as possible. When your fabric is dry enough, it should resemble a play fabric type consistency. Shape it as you like.
Document this experience on social media or [email protected].. Please take a look at the results so that we can introduce them in the photo gallery.
What’s so important about casein plastic?
Milk contains molecules protein It is called casein. When the milk is warmed and acid (vinegar in this case) is added, the casein molecules develop and reorganize into a chain of monomers called polymers. If the cheese-making process comes to your mind when you try this experiment, the process is so similar that you’ll be hooked on something! In fact, the word casein means “cheese” in Latin, and the moist substance used to mold it into jewelry is a bit like cottage cheese. This polymer cures within 24 hours. Also, although not as durable as most industrial plastics, casein is biodegradable and extremely versatile.
Casein plastic was first introduced in the early 1900s and is still used in the manufacture of buttons, buckles, jewelry, fountain pens, beauty accessories and more. To further enhance the structural integrity of this plastic, many manufacturers have added the step of immersing the plastic in formalin, a 5% aqueous solution of formaldehyde. Casein plastic was used to make the gems of Mary I of England, who ruled England between 1553 and 1558 AD.
Originally published in Live Science..