Polymers (Nausheen Choudhury)
Title: Balloon Pop? and Oozing Polymer!
Principle(s) Investigated: polymers, polymer chains, polymerization, macromolecules, synthesizing
Standards:
MS-PS1-3. Gather and make sense of information to describe that synthetic materials come from natural resources and impact society.
Materials:
For the Balloon demonstration
- Balloons
- Wood Skewer (sharp)
- Cooking oil (can help with making sure balloon doesn't pop)
For Polymer
- Glue
- Borax
- Water
- Food Coloring (optional)
- stirring rod / popsicles
- beakers / clear cups
Procedure:
1. Blow up two balloons
2. Pop the first one with a skewer to demonstrate how a balloon can easily be popped
3. Skewer the second balloon near where it is tied and then have the skewer exit towards the top of the balloon where it is slightly darker so it’s not as stretched.
Ask students why didn’t this balloon pop? What could cause such a difference?
Making a Polymer
1. In a beaker or cup mix 4 grams of borax with 100mL of water to create a 4% borax solution
2. In a separate beaker or cup add about 25 mL of glue
3. If desired you can add food coloring to this point into the glue
4. Slowly add the borax solution into the glue and stir and note the changes from liquid glue is becoming cross-linked into a gel.
Student prior knowledge:
Students should be comfortable with accurately measuring out and mixing solutes and solvents in order to form a solution. Students should have an idea of how a chemical and physical reaction take place. Students should know hot to make observations and note the changes that occurs during a reaction
Explanation:
A balloon is made up of polymer chains. These long molecule chains can stretch as the balloon expands. However, a property of balloons is that at the darker end and tied end of them the rubber is much thicker than it is on the sides. The polymers can therefore be stretched much further at these ends than they can at the middle, so the balloon doesn’t pop as easily.
Questions & Answers:
1. What role does Sodium Tetraborate (Borax) in the polymerization process of making “slime”?
Borax is used to help link the polymer molecules together, so they cannot move easily. Borax has borate ions that when they are added to the glue solution will crosslink the glue solution forming a more study compound. More borax will lead to a thicker tightly packed.
2. Is it possible to break a polymer chain?
Yes, the process is called depolymerization where polymer is broken down into a monomer.
3. Polyethylene (PE) is a very well-known and commonly used polymer, what is it made of?
It is made out of ethylene monomers.
Applications to Everyday Life:
1. Polyethylene is the most common type of plastic polymer which is used worldwide to make light plastics to heavy duty plastics. It is responsible for make plastic bottles, plastic bags, boxes and more!
2. Your genetic makeup is made up of polymers! DNA is a long polymer with deoxyribose and phosphate backbone. RNA is a polymer with a ribose and phosphate backbone.
3. Polymers are used to make up starches which are long chains of glucose molecules. Our bodies break down starches we consume from foods like potatoes, grains, and corn in order to produce energy.
Photographs:
A little bit more complex but if you wanted to know about the polymerization of ethylene
Videos: