Photodegrada ti on of poly ( exo-galactosene-co-styrene) in solution and solid state

The photodegradation of poly (exo-galactosene-co-styrene) copolymer 10 dichloromethane and in benzene solution was studied using dibenzoyl proxide as photosensitizer. It was observed that higher photodegradation rate of the copolymer in dichloromethane compared with benzene solution. Decreases in relative and specific viscosity were also observed in the irradiated polymers where the viscosity decreased in the presence of dibenzoyl peroxide and benzophenone photoscnsitize rs , and also with increased concentration of dibenzoyl peroxide with irradiation time . The photodegradation of poly (exo-galactosene-co-styrene)) was investigated in solid state using u. v ,-radiation at A. = 313 nm . The photodegradation rate is followed by U.V. using either: 1. copolymer with different molar ratios of styrene : vinyl sugar : styrene (copolymer 1) (I mole: I mole) and (copolymer II) (1 mole: 3 mole) 1 Different photosensitizers (dibenzoyl peroxide and benzophenone) (0.003 g/mL). 3. Different concentrations of dibenzoyl peroxide (0.003 and 0.01 g/mL). The cqpolymers showed a change in U.V. absorption spectra, whereas the copolymer showed increased the rate of photodegraded compared vvith -polystyrene . The rate of photodegradation of copolymer increases with benzophenone (BPH) and dibenzoyl _peroxide (DBP) as photosensitizers, but the increase in the rate of photodegradation is higher with benzophenone (BPH) , also the rate of photodegradation is increased with increasing the conc-entration of dibenzoyl peroxide (DBP) photosensitizer . It was found that the rate of photodegradation of poly (exo-galactosene-co-styrene) in solution is higher than in polymer film s . The aim of this work is study the photodegradation of poly ( exo-galactosene-co-styrene) in solution and compared it with photodegradation in so lid state by UV.- Vis. spectra.