Chemistry Reference
In-Depth Information
Another material is based on a condensation product of glyoxal with phenol:
OH
H
O
4
HO
OH
O
Cl
+
O
4
HO
OH
H
O
O
O
O
O
O
O
O
Epoxy resins formed by condensations of epichlorohydrin with resorcinol-based phenolic resins
are also formed commercially:
O
O
O
O
O
O
O
O
Several nitrogen-containing aromatic epoxy resins were also commercialized. These are conden-
sation products of aromatic amines with epichlorohydrin. Following are some examples [
140
]:
O
O
+
H
2
N
OH
3
Cl
N
O
O
O
as well as:
O
O
N
N
O
O
The cross-linking reactions of tetrafunctional epoxy resins with aromatic primary diamines were
investigated by spectoscopy [
141
]. UV-Visible and fluorescence spectroscopies of the materials, after
gelation, show significant amounts of amines in the finished products. The infrared spectra also show
that ether formation becomes significant only late in the cure. In addition, during the cure, especially
in air, some oxidations and degradations occur [
141
]. This results in color formation.
