1. What is a Polymer? Withrow University High School May 2008

2. Definition The word polymer comes from the Greek language. poly - mer many - parts So, polymer means “many parts”.

3. A Polymer Molecule A polymer is a Giant Molecule. This giant molecule is a long chain of identical repeating units. These repeating units are called monomers. A polymer molecule are made up of 1000s of monomers. M M M M M M M M

4. Natural Polymers Cotton from plants is a natural polymer and is used to make clothing Silk from silk worms is used to make cloth Wood is a natural polymer used for paper Natural latex from rubber tree is a polymer Rubber can be used to make tires or rubber bands! Crustacean shells are made of chitin, a natural polymer “Carbs” like spaghetti are natural polymers Proteins from eggs and other foods are also natural polymers

5. Man-Made (Synthetic) Polymers Polyethylene is used to make plastic sandwich bags Compact Discs are made from synthetic polymers such as polycarbonate Milk jugs are made from the synthetic polymer polyethylene (HDPE) Polystyrene is used to make Styrofoam cups and cd cases Soda bottles are made from polyethylene terephthalate (PETE) Synthetic polymers are used to make specialty athletic clothing using polymer such as Polyester, Nylon, Lycra or spandex Can you think of any other types of man made polymers and their uses?

6. Symbol The pictures below represent a polymer chain. The “M” stands for monomer. M M M M M M M M M M M M M M M M

7. Elasticity makes the ball bouncy. An elastic object is able to change shape and return to its original shape. What’s going on inside? The molecules stretch when a force is applied. When the force is removed, the molecules return to their original shape. Floor 4. The ball bounces back up. 2. The ball changes shape when it hits the floor. 3a. The ball returns to its original shape. 3b. The ball pushes off the ground 1. The ball drops

8. Polymers make the best elastics M M M M M M M M M M M M M M M M M M M M M M M M A polymer chain at rest A force pulls and stretches the polymer chain. A force pulls and stretches the polymer chain When the force is removed, the polymer chain goes back to its original shape, as long as it was not stretched too much! That would cause the bonds to break.

9. Example Monomer Mono = “One” Put it together with mer to get? –One part Tiny molecular unit that can chemically combine by covalent bonds with other monomers to form a long chain called a Polymer Ethylene monomer molecule (C 2 H 4 )

10. Polymer Synthesis Monomers combine chemically through covalent bonds to form long chain polymer molecules. For Polyethylene the double bond between the carbons is ‘opened’ up and attached to another carbon atom of an ethylene monomer and the process continues as the molecule grows in size.

11. How to Represent Polymers Polyethylene (PE) –Plastic bags, milk jugs, sockets for hip joint replacements, etc. Polyvinyl chloride (PVC) –Piping, house siding, turntable records, etc. Polyvinyl Acetate (PVA) –Glue, binder for making sheets of paper, binder for paints