Chemistry Reference
In-Depth Information
-silylated diamine
proceed more rapidly than with the parent diamine [
113
]. In addition, the products have higher
molecular weights than similar commercial materials made from the parent diamine and sold under
the trade name of Kevlar.
Silylated diamines can also condense with diphenyl esters of aromatic dicarboxylic acids [
114
]:
Preparations of poly-
p
-phenyleneterephthalamide by polycondensations with
N
H
H
O
O
n
N
N
n
Si
Si
+
O
O
O
H
H
-PhOSi(CH
3
)
3
100
o
C
N
N
n
O
O
O
The product, above shown aromatic polyamide, was reported to be of sufficiently high molecular
weight and to be a useful material [
113
].
An example of a specialty aromatic polyamides is a fluorinated polyamide. It was prepared in an
attempt to form a polymer with superior heat stability and resistance to hydrolytic attacks [
76
]:
F
F
H
N
O
O
n
O
F
F
Mitsuru et al. [
113
] reported a direct synthesis of Nomex, an aromatic polyamide, mentioned
above, by a solid state polycondensation:
H
O
O
N
H
2
N
NH
2
Δ
N
n
+
COOH
H
The reactions were carried out at the melting state of the reactants, at first at 360
C and after
oligomerization at 260
C for 1 h.
