The modified polymers were prepared by gradually adding a solution of (0.06mol) of N-(phenyl amino) maleimide dissolved in 250ml of cyclohexanone to a solution of cellulose acetate (0.032 mol) dissolved in 250 ml of cyclohexanone. Both solutions had been prepared under nitrogen atmosphere. The reaction was allowed to occur for 30h at 70◦C, in ultrasonic bath of power 1050 W. The reaction product was precipitated in cold methanol, filtered, and washed with hot methanol using soxhlet system. The recovered polymer was then dried under vacuum at 40 ◦ C.