Chemistry Reference
In-Depth Information
O
O
O
O
hν
O
O
O
O
O
O
+
+
O
O
+
O
O
O
O
CH
2
The mechanism of formation of carboxylic acid groups at the terminal ends of the degradation
products was explained by a Norrish Type II reaction [
559
]:
∗
H
O
O
O
O
hν
O
O
O
O
OH
O
O
+
In addition to the above, photo-Fries rearrangements occur in various aromatic polyester films
upon ultraviolet light irradiation [
560
,
561
]. Also, photo-Fries rearrangements are believed to occur in
polycarbonate resins as well [
562
]. This can be illustrated as follows:
O
hν
O
O
O
+
O
O
O
