An expert is someone who has made all of the possible mistakes in a very narrow field of study
– Niels Bohr
An expert is someone who has made all of the possible mistakes in a very narrow field of study
– Niels Bohr
NylonsNylons
H2N - (CH2)6 - NH2 + HO - C - (CH2)4 - C - OH H2N - (CH2)6 - NH2 + HO - C - (CH2)4 - C - OH
OO
H2N - (CH2)6 - N - C - (CH2)4 - C - OH + H2O H2N - (CH2)6 - N - C - (CH2)4 - C - OH + H2O
OOOO
OO
Adipic AcidAdipic AcidHexamethylene DiamineHexamethylene Diamine
Amide GroupAmide Group
HH
Nylon 6,6Nylon 6,6 - N - (CH2)6 - N - C - (CH2)4 - C -- N - (CH2)6 - N - C - (CH2)4 - C -
OO OO
nn66 66
HH HH
“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
“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
NylonNylon
“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
“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
NylonNylon
May 15 1940 - “Nylon Day” Four million pairs go on sale
throughout US Supply exhausted in 4 days.
May 15 1940 - “Nylon Day” Four million pairs go on sale
throughout US Supply exhausted in 4 days.
PolyurethanesPolyurethanes
Reaction does not involve splitting out of a small moleculeReaction 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 + HO - (CH2)2 - OH
O = C = N - (CH2)6 - N - C - O - (CH2)2 - OH O = C = N - (CH2)6 - N - C - O - (CH2)2 - OH
OO
Hexamethylene DiisocyanateHexamethylene Diisocyanate Ethylene GlycolEthylene Glycol
Urethane LinkageUrethane Linkage
HH
usw.usw.
Linear & branched polymersex: polyethylene
Linear & branched polymersex: polyethylene
LinearLinear
Branched - short branches
Branched - short branches
Linear & branched polymersex: polyethylene
Linear & branched polymersex: polyethylene
~~~CH2 - CH - CH2 - CH2.
~~~CH2 - CH - CH2 - CH2.
C4H9C4H9--
~~~CH2 - CH - CH2 - CH2 - CH2 - CH2.
~~~CH2 - CH - CH2 - CH2 - CH2 - CH2.
C4H9C4H9--
Formation of short chain branches in polyethylene
Formation of short chain branches in polyethylene
~~~CH2 - CH ~~~CH2 - CH
CH2 - CH2CH2 - CH2
CH2CH2..
CH2HCH2H
~~~CH2 - CH ~~~CH2 - CH
CH2 - CH2CH2 - CH2
CH2CH2.CH2.CH2HH
CH2 = CH2CH2 = CH2
CH2 = CH2CH2 = CH2
Other types of branchingOther types of branching
shortshort longlong starstar
Branching suppresses or prevents chain movement & "crystallization" in polymers
Branching suppresses or prevents chain movement & "crystallization" in polymers
Branching Branching
Another way to make chains branchAnother way to make chains branch
Use multifunctional (f>2) monomersUse multifunctional (f>2) monomers
OHOH
+ CH+ CH22OO**
**
**
OHOH
CHCH22OHOH
OHOHCHCH22
OHOH
CHCH22
CHCH22
OH
CHCH22
OHOH
OHOHOHOH
CHCH22
CHCH 22
Network formationNetwork formationFurther 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
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
BakeliteBakelite
Bakelite telephoneBakelite telephone
Bakelite microphoneBakelite microphoneBakelite cameraBakelite camera
Clear Bakelite itemsClear Bakelite items
Bakelite radioBakelite radio
Phenolic resin/celluloid clockPhenolic resin/celluloid clock
Bakelite - Material of a Thousand UsesBakelite - Material of a Thousand Uses
Crosslinking Crosslinking
Ex: rxn of natural rubber or poly(isoprene)Ex: rxn of natural rubber or poly(isoprene)
with sulfur - interconnects the chains by reacting with the double bonds
(vulcanization)
with sulfur - interconnects the chains by reacting with the double bonds
(vulcanization)
H
CH2 -
CH3-
C = C- CH2
--
-H
CH2 -
CH3-
C = C CH2
--
-H
CH2 -
CH3-
C = C CH2
--
-
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