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Plastics

Plastics. We use this matter resource in so many ways—but most people know very little about them. What are most plastics used today made from?. Electricity Coal Trees Rocks Petroleum Bacterial excretions. What are most plastics used today made from?. 5) Petroleum

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Plastics

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  1. Plastics We use this matter resource in so many ways—but most people know very little about them.

  2. What are most plastics used today made from? • Electricity • Coal • Trees • Rocks • Petroleum • Bacterial excretions

  3. What are most plastics used today made from? 5) Petroleum But Natural Gas is also commonly used

  4. What two elements are the main components of petroleum? • Hydrogen & Oxygen • Carbon & Hydrogen • Carbon & Oxygen • Sulfur & Oxygen • Carbon & Sulfur • Sulfur & Hydrogen

  5. What two elements are the main components of petroleum? 2) Carbon & Hydrogen (Oil is often referred to as a Hydro-carbon)

  6. What is true about all ‘Plastics’? • They’re made of polymers • They must be made up of only carbon and hydrogen • They’re flexible solids that melt at high temperatures • They’re a lightweight material that does not chemically react with anything

  7. What is a polymer? Poly = Many mer = Units So, a polymer is a large molecule composed of many repeating sub-units (called monomers)

  8. Example: • Monomer = CH2 • Polymer = -CH2- CH2-CH2- CH2-CH2- CH2-CH- etc. • Plastic = Polyethylene

  9. WHY WOULD IT BOND AS CH2? • Draw a carbon atom: + 6 6 N How many more electrons does carbon need to have a complete outer shell?

  10. Needs 4 more—two from hydrogen… Covalent bonds + 1 + 6 6 N + 6 6 N + 6 6 N Covalent bonds + 1 …and two from a carbon on either side.

  11. Polyetheylene (CH2- CH2) • HOW IS IT COMMONLY USED? • PET (Polyester fibers for clothes, soft drink bottles, etc.) • HDPE (Milk jugs, detergent containers, etc.) • LDPE (grocery bags, plastic wrap, coffee can lids, etc.) Source = http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/topic5.html

  12. High vs. Low Density Polyethylene • High-density polyethylene (HDPE) has minimal branching, which makes it more rigid and less permeable than LDPE • Low-density polyethylene (LDPE) has more extensive branching, resulting in a less compact molecular structure.

  13. Polyvinyl chloride (PVC) –(CH2CHCl)- • *The addition of Chlorine atoms makes it more resistant to oils, and a lower permeability to most gases. • COMMONLY USED AS… • Drain pipes, Vinyl siding, etc. Source = http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/topic5.html

  14. COMMONLY USED AS… • Styrofoam packaging material (when injected with gases), compact disk cases, etc. Source = http://www.elmhurst.edu/~chm/onlcourse/chm110/outlines/topic5.html

  15. Summary of Plastic Types

  16. Can’t we just recycle plastic? • There are many different types of plastic—and they must be separated which complicates the process. Just one incorrect plastic mixed with thousands of the correct type can ruin the batch. • While #1 (PET) and #2 (HDPE) are commonly recycled, the rates of recycling are far lower (~28% in 2010) than newspaper (80%) and cardboard (70%). • Recycling plastic requires ENERGY (to break the polymers down and re-form them into a new product). Since the dominant way we supply energy today is fossil fuels like petroleum, it is easier to just use that petroleum to directly make new plastic.

  17. Plastic Usage Statistics (EIA.gov)

  18. How does single stream recycling work?

  19. Understanding Check--click in your answers based upon what you learned today.

  20. What are most plastics used today made from? • Trees • Rocks • Petroleum • Bacterial excretions • Sand • Air

  21. What two elements are the main components of petroleum (and thus plastics)? • Sulfur & Oxygen • Carbon & Sulfur • Carbon & Nitrogen • Carbon & Hydrogen • Nitrogen & Hydrogen • Sulfur & Hydrogen

  22. Which of the following is the monomer that makes up polyethylene? (Hint: think about the electron arrangement of the atoms as they form a long chain) • CH • CH2 • CH4 • CH5

  23. Which of the following is NOT an actual problem with plastic recycling • Recycling requires energy so it is easier to just make new plastic from the petroleum. • There are many different plastic types which must be separated before they can be processed. • Recycled plastic has a strong odor due to the process that it goes through. • All of these are actual problems.

  24. The picture below shows the molecular arrangements for two types of Polyethylene. • ‘A’ is #4 (LDPE) while ‘B’ is #2 (HDPE) • ‘B’ is #4 (LDPE) while ‘A’ is #2 (HDPE) A B

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