1. Chemeketa Community College
Polymers:
Macromolecules
Chapter 21
Larry Emme
Chemeketa Community College

2. What is a “mer”?
The terms polymer and monomer are part of our everyday speech.
Poly = many Mono = one
“Mer” is derived from the Greek meros, meaning “part.” So, a monomer is a “one part” and a polymer is a “many part.”

3. Macromolecules

4. Synthetic macromolecules touch every phase of our lives.
There exist in nature some very large molecules (macromolecules) that contain tens of thousands of atoms.
Starch, glycogen, cellulose, proteins, silk, and DNA
Synthetic macromolecules touch every phase of our lives.

5. Polyethylene Polyethylene is an example of a synthetic polymer.
Ethylene, derived from petroleum, is made to react with itself to form polyethylene.
Poly “the alkene name”

6. Polymerization
The process of forming very large, high-molar-mass molecules from smaller units is called polymerization.
The large molecule, or unit, is called the polymer.
The small unit is called the monomer.
Ethylene is a monomer; polyethylene is a polymer
Because of their large size, polymers are often called macromolecules or plastics.

7. Synthetic Polymers

10. Classification of Synthetic Polymers
Rubberlike materials or elastomers
Flexible films
Synthetic textiles and fibers
Resins (or plastics) for casting, molding, and extruding
Coating resins for dip-, spray-, or solvent-dispersed applications
Miscellaneous (e.g. hydraulic fluids, foamed insulation, ion-exchange resins)

11. Polymer Types

12. Polymer Types Addition Polymer Condensation Polymer
Produced by successive addition reactions
Polyethylene is an example of an addition polymer.
Condensation Polymer
Formed when monomers combine and split out water or some other simple substance.
Essentially a substitution reaction
Nylon is a condensation polymer.

13. Polymer Types Thermoplastic Polymers Soften on reheating
Thermosetting Polymer
Set to an infusible solid and do not soften on reheating

14. Addition Polymerization

15. Addition Polymerization
Addition polymerization starts with monomers that contain C=C bonds.
When these bonds react, each alkene carbon bonds to another monomer.

16. Learning Check
Draw a three-unit portion of polypropylene. 16

17. Propylene is CH2CHCH3 H H CC H CH3 Learning Check
Draw a three-unit portion of polypropylene.
Propylene is CH2CHCH3
First isolate the double bond: H H
CC H
CH3 17

18. Propylene is CH2CHCH3 H H CC H CH3 Learning Check
Draw a three-unit portion of polypropylene.
Propylene is CH2CHCH3
Next replace the π bond with two electrons H H
CC H
CH3 18

19. Propylene is CH2CHCH3 H H CC H CH3 Learning Check
Draw a three-unit portion of polypropylene.
Propylene is CH2CHCH3
Swing the π electrons to either side of the double bond H H
CC H
CH3 19

20. Propylene is CH2CHCH3 H H CC H CH3 Learning Check
Draw a three-unit portion of polypropylene.
Propylene is CH2CHCH3
Swing the π electrons to either side of the double bond H H
CC H
CH3 20

21. Propylene is CH2CHCH3 H H H H CC CC H CH3 H CH3 Learning Check
Draw a three-unit portion of polypropylene.
Propylene is CH2CHCH3
Connect the group with an identical group H H H H
CC
CC H
CH3 H
CH3 21

22. Propylene is CH2CHCH3 H H H H CC CC H CH3 H CH3 Learning Check
Draw a three-unit portion of polypropylene.
Propylene is CH2CHCH3
Connect the two groups together H H H H
CC
CC H
CH3 H
CH3 22

23. Learning Check Draw a three-unit portion of polypropylene. n
Polypropylene polymer n 23

24. Learning Check
Show one unit of a copolymer made from the monomers vinyl acetate and ethylene. 24 24

25. H H H H CC CC H H H O CO CH3 Learning Check
Show one unit of a copolymer made from the monomers vinyl acetate and ethylene. H H H H
CC
CC
Ethylene H H H O
Vinyl acetate
CO
CH3 25 25

26. H H H H CC CC H H H O CO CH3 Learning Check
Show one unit of a copolymer made from the monomers vinyl acetate and ethylene. H H H H
CC
CC
Ethylene H H H O
Vinyl acetate
CO
CH3 26 26

27. H H H H CC CC H H H O CO CH3 Learning Check
Show one unit of a copolymer made from the monomers vinyl acetate and ethylene. H H H H
CC
CC
Ethylene H H H O
Vinyl acetate
CO
CH3 27 27

28. H CC H O CH3 CO CC Learning Check
Show one unit of a copolymer made from the monomers vinyl acetate and ethylene. H
CC H O
CH3
CO
CC
Ethylene
Vinyl acetate 28 28

29. H CC H O CH3 CO CC Learning Check
Show one unit of a copolymer made from the monomers vinyl acetate and ethylene. H
CC H O
CH3
CO
CC n 29 29

32. Free radicals catalyze or initiate many addition polymerizations.
Organic peroxides (ROOR) are frequently used for this purpose.
The reaction proceeds in three steps:
Free-radical formation
Propagation of polymeric chain
Termination

33. Addition Polymers: Use and Reuse (Recycling)

34. Recycling
Unfortunately, the C-C bonds of common addition polymers, like polyethylene, are different from those of most natural polymers and cannot be metabolized by many microorganisms.
Recycling seems to be the best solution to the problem of disposing of these long-lived addition polymers.

35. Recycling 35 35

36. Choose as a plastic container those with recycle numbers 1, 2, 4, and/or 5 These plastics are considered safest for the storage of food and drink, as they appear not to leach chemicals into contained food and drink at room temperatures.

37. Avoid using plastic containers in the microwave Any material has a greater chance of leaching chemicals when heated. The better bets for containers in the microwave are those made of glass and ceramic.
Avoid plastic cling wraps in the microwave These plastic wraps have been shown to leach chemicals when heated.

38. Avoid water bottled in plastic containers Not only is the water sitting in the bottle for possibly a long time, increasing the chance of the leaching of chemicals from the container, but the water in the bottled water industry is much more poorly monitored than a municipal water system. Also, don't re-use the containers for food or drink storage.

39. Klean Kanteen Stainless-Steel Water Bottle

40. Avoid using polyvinyl chloride (PVC) plastics (plastic recycle number 3) "The nonprofits Center for Health, Environment & Justice (CHEJ) and Environmental Health Strategy Center have asked companies to phase out the use of polyvinyl chloride (PVC), a type of plastic widely used in construction and consumer goods, because it poses serious health threats at every stage of its life cycle." PVC is made with phthalates, which can leach into the food or liquid contained, and is shown to have adverse health affects.

41. Avoid polystyrene as a food or drink container (plastic recycle number 6) These are the foam trays, egg cartons, opaque plastic cutlery, etc. The chemical styrene can leach into food and drink and cause adverse health effects.

42. Avoid as a food or drink container polycarbonates and other plastic recycle number 7 plastics The plastic recycle number 7 includes many different plastics, but is often polycarbonate (a common material from which sports drinking bottles are made), which can leach Bisphenol-A (BPA) into the contained food or drink. Bisphenol-A (BPA) is an endocrine disruptor, and there is considerable evidence of adverse health effects at low doses.

43. Butadiene Polymers

44. Butadiene Polymers
Natural rubber is a polymer of isoprene (2-methyl-1,3-butadiene).

45. Copolymers
A copolymer contains two different kinds of monomer units.

46. Vulcanized Rubber
Vulcanization extends the useful temperature range of rubber products and imparts greater abrasion resistance to them.
The vulcanization process is usually accomplished by heating raw rubber with sulfur and any other auxiliary agents.

47. Geometric Isomerism in Polymers

48. Geometric Isomerism in Polymers
The recurring double bonds in isoprene and butadiene polymers make it possible to have polymers with specific spatial orientation as a result of cis-trans isomerism.

49. Geometric Isomerism in Polymers
Natural rubber is cis-polyisoprene with all-cis configuration about the carbon-carbon double bonds.

50. Geometric Isomerism in Polymers
Gutta-perch, also obtained from plants, is a trans-polyisoprene with an all-trans configuration.

51. Geometric Isomerism in Polymers51 51

52. The End