Chemistry Reference
In-Depth Information
CH
2
-CH
2
H
250°C
H
2
O
catalyst
NH
N
CH
2
C
m CH
2
5m
C=O
(1-5)
O
CH
2
-CH
2
polycaprolactam (Nylon 6)
1-13
CH
3
CH
3
CuCl/pyridine
O
+ iH
2
O
i
OH + ½O
2
complex
CH
3
CH
3
(1-6)
poly(phenylene oxide)
1-14
Zn (O
2
C-CH
3
)
2
COCH
3
+ n HOCH
2
-CH
2
OH
OCH
2
CH
2
OC
C
+
2n CH
3
OH
n CH
3
OC
n
285°C
O
O
O
O
poly(ethylene terephthalate)
(1-7)
A polyfunctional monomer can react with more than two other molecules to
form the corresponding number of new valence bonds during the polymerization
reaction. Examples are divinyl benzene,
CH
=
CH
2
CH
=
CH
2
1-15
in reactions involving additions across carbon
carbon double bonds and glyc-
erol or pentaerythritol
(C(CH
2
OH)
4
)
in esterifications or other
reactions of
alcohols.
If an a-functional monomer reacts with a b-functional monomer in a nonchain
reaction, the functionality of the product molecule is a
2. This is because
every new linkage consumes two bonding sites. Production of a macromolecule
in such reactions can occur only if a and b are both greater than 1.
The following points should be noted:
1.
Use of the term functionality here is not the same as in organic chemistry
where a carbon
b
1
2
carbon double bond, for example, is classified as a single
functional group.
2.
Functionality refers in general to the overall reaction of monomers to yield
products. It is not used in connection with the individual steps in a reaction
sequence. The free radical polymerization of styrene, for example, is a chain
reaction in which a single step involves attack of a radical with ostensible
