Abstract
The photofading rate of Acridine Orange N in a dioxane-ethanol mixture has been studied in the presence of polymers having certain ultraviolet absorption groups, 2-hydroxybenzophenone (HBP), 2, 4-dihydroxybenzophenone (DHBP) and phenyl benzoate (PB).
Polymer K was obtained from styrene-4-benzoxystyrene copolymer (polymer E) by Photo-Fries rearrangement. Polymer SB was obtained by copolymerization of styrene and 2-hydroxy-4-(3-methacryloxy-2-hydroxypropoxy) benzophenone (BPMA). Since the conversion of photo-Fries rearrangement of polymer E was low, polymer K contained a small fraction of HBP unit and a large fraction of PB unit as ultraviolet absorption groups, while polymer SB contained only HBP unit.
The results of photofading of Acridine Orange N in the solutions containing these polymers are summarised as follows. Polymer K, polymer SB, HBP and DHBP played roles of retarder on the photofading rate of the dye with the extents of the effects in the order: polymer SB>DHBP>HBP>polymer K, while polymer E and PB acted as accelerator.
