Chemistry Reference
In-Depth Information
STEP GROWTH POLYMERIZATION
E
XAMPLES
Ring-opening polymerization
O
C
O
NH
NH (CH
2
)
5
C
n
n
nylon 6
caprolactam
Polyurethane formation
n
HO-R-OH +
n
O=C=N-R
′
-N=C=O
diol
diisocyanate
O
O
H
OROC
NH
R
NH
C
n
-1
O
ROC
NH
R
NCO
′
′
polyurethane
Step growth polymerization can also take place without splitting out a small
molecule. Ring-opening polymerization, such as caprolactam polymerization
to nylon 6, is an example. Polyurethane formation from a diol and a di-
isocyanate is another step growth polymerization in which no small molecule
is eliminated.
