1. Single and Double Bonds
Some Basic Chemistry:
Single and Double Bonds C – H
CH4 C – H
C2H6 C – H
C2H4

2. Some Basic Chemistry: Functional Groups
CH2=CH2
Ethylene
R–OH
R–C–OH = O
R–C–O–R +
Alcohol
Carboxylic Acid
Ester
R–NH2
R–C–OH
R–C–NH–R +
Carboxylic Acid
Amine
Amide = O
Functional groups - small groups of atoms held together in specific arrangement by covalent bonds
Responsible for principal chemical properties of molecule

3. Condensation Reactions
Some Basic Chemistry:
Condensation Reactions O
Ethyl Alcohol
or Ethanol
reversible
reaction
CH3 - C - OH + CH3 - CH2 - OH
CH3 - C - O - CH2 - CH3 + H2O
Acetic Acid
Ethyl Acetate O
Ester linkage

4. Now…to make a Polymer + These molecules are monofunctional:
To make linear chains need bifunctional molecules:
Except, reaction goes step-wise

5. Polyester - step 1 Monomers Dimer O O
HO - C - (CH2)n - C - OH + HO - (CH2)m - OH O O
HO - C - (CH2)n - C - O - (CH2)m - OH + H2O
Dimer

6. Polyester Trimer HO - C - (CH2)n - C - OH O
HO - C - (CH2)n - C - O - (CH2)m - OH +
HO - C - (CH2)n - C - O - (CH2)m - O - C - (CH2)n - C - OH
- H2O
Trimer
M1 + M M2
M2 + M M3
M2 + M M4
M3 + M M4
M4 + M M5
M3 + M M5
M5 + M M6
Etc.
Reacting diacid & dialcohol give polyester

7. Nylons O H2N - (CH2)6 - NH2 + HO - C - (CH2)4 - C - OH
H2N - (CH2)6 - N - C - (CH2)4 - C - OH + H2O
Adipic Acid
Hexamethylene Diamine
Amide Group H

8. - N - (CH2)6 - N - C - (CH2)4 - C - O n 6 H
Nylon 6,6
“I am making the announcement of a brand new chemical textile fiber ---derivable from coal, air and water -- and characterized by extreme toughness and strength --”
Charles Stine V.P. for research, Du Pont, 1938

9. Nylon
“I am making the announcement of a brand new chemical textile fiber ---derivable from coal, air and water -- and characterized by extreme toughness and strength --”
Charles Stine V.P. for research, Du Pont, 1938

10. Nylon
May “Nylon Day” Four million pairs go on sale throughout US Supply exhausted in 4 days.

11. Nylon Parachute WWII

12. Post WWII stocking sale, San Francisco.

13. Polyurethanes
Reaction does not involve splitting out of a small molecule
O = C = N - (CH2)6 - N = C = O + HO - (CH2)2 - OH
O = C = N - (CH2)6 - N - C - O - (CH2)2 - OH O
Hexamethylene Diisocyanate
Ethylene Glycol
Urethane Linkage H
usw.

14. Linear & branched polymers ex: polyethylene
- short
branches

15. Linear & branched polymers ex: polyethylene
~~~CH2 - CH - CH2 - CH2.
C4H9 -
~~~CH2 - CH - CH2 - CH2 - CH2 - CH2.
Formation of short chain branches in polyethylene
~~~CH2 - CH
CH2 - CH2
CH2 .
CH2H
.CH2 H
CH2 = CH2

16. Low density polyethylene (LDPE)
(short branches)

17. Other types of branching
short
long
star
Branching suppresses or prevents chain movement & "crystallization" in polymers

18. Branching Another way to make chains branch
Use multifunctional (f>2) monomers OH
+ CH 2 O * OH CH 2

19. The phenol + formaldehyde rxn

20. Network formation
Further reaction under heat & pressure builds up densely cross-linked network. This is Bakelite, a thermosetting polymer. Once reaction is complete, material cannot be reheated and/or reformed
Bakelite

21. Bakelite - Material of a Thousand Uses
Clear Bakelite items
Phenolic resin/celluloid clock
Bakelite telephone
Bakelite camera
Bakelite radio
Bakelite microphone

22. Crosslinking
Take linear polymer chains & link using covalent bonds

23. Crosslinking Ex: rxn of natural rubber or poly(isoprene) H CH2 - CH3 -
C = C
- CH2
CH2
with sulfur - interconnects the chains by reacting with the double bonds
(vulcanization)

24. Crosslinking