PREPARATION AND PHOTOLYSIS OF POLY-4 prime -ACETYLACRYLOPHENONE AND ITS COPOLYMERS WITH STYRENE AND METHYL METHACRYLATE.

In the reported experiments, poly-4 prime -acetylacrylophenone (P4AcAP) and its copolymers with styrene (4AcAP/S) and methyl methacrylate (4AcAP/MMA) were prepared. Ultraviolet (UV) spectra of these polymers show an absorption band at 29,500 cm** minus **1 ( epsilon equals 270) of n- pi * character. The low temperature emission spectra of films of copolymers studied exhibit a less resolved vibrational structure and are bathochromically shifted with respect to those of polyacrylophenone and its styrene and methyl methacrylate copolymers. The emission decay is slightly nonexponential and has a lifetime of about 0. 02 sec. Quantum yields of main chain scission in solution with 366-nm radiation are of the same order as those of the unsubstituted polyacrylophenone. Substitution by a strong electron-accepting group, in comparison with polyacrylophenone, influences the value of the quantum yield only a little but prolongs the lifetime of the lowest triplet state.