Quench your thirst from a distance like so:
I started with a large collection of plastic straws from before the days of their degradation. These straws stretch to around 13” when fully extended.
I pushed one end of the straw into the end of another straw, then that straw into another, and so on. To further the effectiveness of the length, I wrapped painters tape around the areas when I connected the straws.
I was able to reach a length of about 80 inches before I could no longer get enough suction to pull my drink through the straw.
Can you beat 80"? Give it a try today.
by Kristie Hill, Library Associate
Turn Milk into Plastic!?!
It sounds crazy, right? How can you make milk into plastic? I thought the same thing before I did a little research discovering this activity. According to Teisha Rowland, PhD and Sandra Slutz, PhD with Science Buddies “from the early 1900s until about 1945, milk was commonly used to make many different plastic ornaments, including buttons, decorative buckles, beads and other jewelry, fountain pens, the backings for hand-held mirrors, and fancy comb and brush sets. Milk plastic (usually called casein plastic) was even used to make jewelry for Queen Mary of England! In this activity you will make your own casein plastic out of hot milk and vinegar.”
I thought this was so interesting and showed how an everyday grocery item for most people can be used in different ways outside of what we use it for traditionally.
So how does this work and what does it look like? Turns out it is a lot simpler than you might think! Check out how to do your own experiment turning milk into plastic below. Supplies
What is great about this experiment is that you probably have all the materials you need in your cabinet or refrigerator. If you don’t they are easily to get at your closest convenient store or grocery.
Milk (1 Cup) (I used whole milk.)
White Vinegar (4 Teaspoons)
Measuring Cup
Measuring Spoons
Mug or Heat-Resistant Cup (Large Enough to Hold 1 Cup of Milk0
Paper Towels
Spoon
Stove or Microwave (I used a stove but this is just as easily done in a microwave)
Optionals: Glitter (For me a must!), Cookie Cutters, Food Coloring, Markers
Step 1
Take your 1 cup of milk and place in a pot on the stove.
If you are doing this in the microwave put your milk in a heat resistant container in the microwave.
Step 2 Heat up the milk in your pot, you want it just about to boil where it is steaming. I heated it on my stove’s high temperature setting. This was my first ASMR moment too so listen to that boil!
If you are heating in the microwave, set it to 50% power or medium-high for 5 minutes. (If you see it start to bubble that means it is time to take it out.)
TIP: If you aren’t sure of what temperature the milk should be Think of how hot you want either your latte or hot chocolate.
Step 3
While your milk is heating up, pour the 4 teaspoons of vinegar into your heat resistant mug.
Step 4
Once the milk is hot and steaming, carefully pour it into your mug. It should curdle (form little clumps) as soon as the milk mixes with the vinegar.
TIP: Think of expired milk that has all of those clumps in it, that is what it should look like but a little more liquidy.
What happens when the milk and vinegar are mixed together? Why do you think this is?
Step 5
Grab a spoon and stir the milk and vinegar in the mug slowly for a few seconds.
After you have stirred, you are going to let the mixture cool down. This is the perfect time to put down 4-5 layers of paper towels on your counter or table.
TIP: I put a cutting board under my paper towels to avoid anything getting on the counter. You can also use a plastic or silicone placemat if you have one.
Step 6
Okay here is one of the more difficult steps. You want to get all those curds out the mug and onto your stack of paper towels. The goal is to get as many curds as you can.
Use a spoon to scoop out the curds. You can do this by tilting the spoon against the inside of the mug to let excess liquid drain out while retaining the curds in the spoon.
If you have a colander or strainer that has a fine mesh then you can try pouring the contents from the mug into it to separate the liquid from the curds.
Fold the edges of the paper towel stack over the curds to get all the excess liquid out.
Step 7
Once you have all your curds clumped together on the paper towels. It is time to start kneading the curds into a ball. You want it to look similar to a ball of dough like if you are kneading bread or rolling cookie dough balls.
NOTE: If you want to add color or glitter now is the time to do so. (I added purple and black glitter to mine.) This is the case in plastic!
How do the kneaded curds feel and look differently than the curds did originally?
Step 8
If you want to make the casein plastic into something now is the time that you shape or mold it!
You can use cookie cutters to shape it (you will need to double or triple your amounts of milk and vinegar to do this) or if you are more patient you can shape it by hand like I did.
You will let your casein plastic creation dry for 48 hours (2 days) or more. Once it has dried completely the casein plastic will be hard.
The Science of What Happened
Science Buddies has a great breakdown of what happened throughout this activity and you can check out the summary below.
“When you added 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. The white chunks are curds. You should have been able to use a spoon to separate the curds from most of the liquid. Additional drying of the curds with the paper towels should have made the curds ready to knead into a ball and use as casein plastic, which can be molded and decorated.”
I don’t know about you but I fully feel like Bill Nye the Science Guy now.
by Stephanie Johnson, Teen and Technology Librarian
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