Chemistry Reference
In-Depth Information
STEP GROWTH POLYMERIZATION
E
XAMPLES
Polyamide
O
O
n
+
n
H
N-(CH
)
-NH
HO
C
(CH
2
)
4
COH
2
2
6
2
hexamethylenediamine
adipic acid
O
O
-H
2
O
C
(CH
2
)
4
CNH
(CH
2
)
6
NH
n
nylon 66
Polyester
O
O
C
OCH
3
n
HO-CH
2
CH
2
-OH
n
CH
3
O
C
+
ethylene glycol
dimethyl terephthalate
O
O
-CH
3
OH
C
OCH
2
CH
2
C
n
poly(ethylene terephthalate)
The most common form of step growth polymerization is condensation poly-
merization. Condensation polymers are generally formed from simple reac-
tions involving two different monomers. The monomers are difunctional,
having a chemically reactive group on each end of their molecules. Examples
of condensation polymerization are the formation of nylon 66, a polyamide,
and of poly(ethylene terephthalate), a polyester. Because condensation poly-
