1. 7B20: Modeling Polymers

2. Background Plastics have different properties, but they all belong to a group of materials called Polymers. Mono = prefix that means “one” in Greek. Poly = prefix that means “many” in Greek. Polymers = compounds made of thousands of repeating smaller molecules. Monomer = molecule that repeats in a polymer So Polymers are made of many Monomers.

3. Challenge Questions Give 3 examples of how models are used to show something.

4. Models Scientists use models to help explain things. Models do not have to look like the real thing. Models do have to act like it in one or more important ways. Some people make models from legos, popsicle sticks, or styrofoam. Monomers can be modeled with paper clips.

5. Monomers Unconnected paper clips represent Monomers Draw some unconnected paper clips. If you put them into a bottle and try to pour them out, how quickly do they pour out? How easy is it to pull out just one?

6. Polymers Now link and draw 6 paper clips together to form Polymers. Each clip is a Monomer. How easy would it be to pour these out of a bottle? Link all clips together to form a 24-link chain. Is that easy to pour out of a bottle? Can you pull out just one single paper clip?

7. Cross-Linked Polymers Separate the long chain back into 6-link polymers and put them into parallel rows. Connect the rows with more paper clips. Draw this. This is called a Cross-Linked Polymer. How easy would it be to pour out of a bottle?

8. 7B20 Polymer Model Analysis Write questions + 1 paragraph each 4. The models act a lot like the molecules. Based on what you observed, how does cross- linking affect the properties of a polymer? 5. All plastics are polymers. What advantages do you think polymers have over monomers?