1. By: Si Man Lam Date: June 7, 2005
Polymers
By: Si Man Lam
Date: June 7, 2005

2. What is a Polymer? Polymers are commonly known as plastics
Long chain of carbon molecules with repeating units joined by covalent bonds
Each repeating unit known as a monomer
Polymer is Greek for “many parts”
Imagine a bowl spaghetti – that is how the molecular arrangement of polymers looks

3. Two Groups of Polymers Thermoplastic
Soften with heat and harden with cooling
Examples: HDPE, LDPE, PET
Thermosets
Cured or Hardened with heating
Examples: Bakelite, Epoxy, Polyurethane

4. Natural Polymers Existed since the beginning of time
Examples include shellac, turtle shells and horns, latex, silk
Chemically modified natural polymers include rubber and gun cotton

5. World War II: Revenge of the Synth
Reduced supply of natural sources of latex, wool, silk and other materials
Emergence of synthetic polymers
Increased usage and development of nylons, acrylics, neoprene, polyethylene

6. Bakelite Developed in 1907 by Leo Baekeland
First synthetic polymer and first widely manufactured plastic
At that time used to make everything from telephones and radios to auto parts, furniture, and jewelry

7. Polyethylene Simplest and most basic polymer chain
Made up of a long chain of Ethane molecules (CH3-CH3)
Monomer form is Ethylene (CH2=CH2)
Available in Low Density and High Density Variations
Commonly used for milk bottles, medicine bottles, bags, Toys

8. PET Polyethylene Terephthalate
Derivative of polyethylene with terephthalate molecule included in the chain
Durable and clear properties with oxygen and water barrier
Great for soda bottles and drink containers

9. Teflon PolyTetraFluoroEthylene
Discovered by Accident by Roy Plunkett at Dupont in 1938
Secret Weapon of WWII - used to coat bearings and metal surfaces to reduce friction and wear and tear
Now used for non stick pots and pans and dental floss

10. Other Commonly Used Polymers
Polypropylene (Microwavable Containers)
Polyvinylchloride (Water pipes)
Polystyrene (Foam Cups, Packing Peanuts)
Polycarbonate (aka Lexan, Bulletproof Glass)
Polyamide (Nylon)

11. What Is Used to Make Plastic Stuff?
Injection Molding
Injection Blow Molding
Injection Stretch Blow Molding
Extrusion Molding
Extrusion Blow Molding
Rotational Molding

12. Why Use Plastic? Looks Good Durable Flexible Light Weight
Easy to shape and color
Cheap

13. The Plastic Age Stuff made out of plastic is everywhere
Cell phones, computer parts, car parts, tables, chairs, etc.
New uses for plastic being discovered everyday
What used to be glass is now made in plastic
What used to be metal is now made in plastic
What used to be wood is now made in plastic
Plastic has revolutionized the world

14. References http://web.umr.edu/~wlf/CHEM381/chap11.html