“…Photooxidation of irradiated PFS-isomers leads to increase in the intensity of absorbance in the bands with noticeable shift of energy at (1582-1449 cm -1 ) for o-PFS, at (1588-1449 cm -1 ) for m-PFS and at (1506 cm -1 ) for p-PFS. The shift in these ranges can be attributed either to the C = O stretching vibration of aromatic ketones, or to the stretching vibration of the substituted benzene ring (Millan, Locklin, Fulghum, Baba, & Advincula, 2003). The other increases in the region of (1219-1111 cm -1 ) of o-PFS, (1239-1137 cm -1 ) of m-PFS and (1224-1152 cm -1 ) of p-PFS, indicates that there is an increase in the number of C = C that resulted from hydrogen abstraction during chains scission process, or as indicated in the Table 5, it results from the (C -O -C) stretching vibration.…”