Chemistry Reference
In-Depth Information
diamines and aliphatic dicarboxylic acids. For nylon A,B, A is the number of
carbons in the aliphatic diamine and B is the number of carbons (including the
carbonyl carbons) in the dicarboxylic acid. Thus, nylon 4,6 is derived from
1,4-diaminobutane and adipic acid.
O
R
′
RCO
2
H+R
′
NH
2
+ H
2
O
R
H
Amide
O
H
H
O
H
H
H
H
H
H
N
N
+
H
2
N
C
NH
2
HO
2
C
C
CO
2
H
C
C
B-2
C
C
B-2
A
A
x
Nylon A,B
O
O
O
H
H
H
H
OH
H
2
N
N
N
+
HO
NH
2
C
C
C
C
4
4
O
x
Adipic acid
Nylon 4,6
The largest volume nylon is nylon 6,6. It has good properties and the
starting materials are readily available. Adipic acid can be produced by the
oxidation of cyclohexane. 1,6-Hexamethylene diamine is produced from
adiponitrile. Adiponitrile can be produced from adipic acid or from butadiene
[18].
O
OH
O
HNO
3
or O
2
Cat
O
2
Cat
OH
HO
+
O
Adipic acid
N
H
2
Cat
H
2
N
N
C
C
NH
2
1,6-hexanediamine
Adiponitrile
The second largest volume nylon is nylon 6. Nylon 6 is not made from a
diamine and a dicarboxylic acid, but from a six carbon cyclic amide. Cyclic
amides are called lactams and caprolactam is a six-carbon lactam. Capro-
lactam can be made by the reaction of cyclohexanone with hydroxylamine,
followed by a Beckmann rearrangement.
H
+
H
OH
H
H
O
N
O
+
N
H
+
N
O
O
N
H
NH
2
OH
+
H
+
,
H
+
−
−
−
H
2
O
−
H
2
O
+H
+
Cyclohexanone
Caprolactam
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