Radiolytic stabilization of poly(hydroxybutyrate)

Stabilization against gamma irradiation effects on Brazilian poly(hydroxybutyrate) (PHB) films was investigated by using commercial additives. With the most effective additive the G value of main chain scissions decreased from 8.6 to 1.5 scissions/100 eV in the absorbed dose range up to 35 kGy. Irradiation increased the biodegradability of the samples, whereas the additives-induced reduction in biodegradability. Irradiation treatment did not influence the degree of crystallinity. Protonic nuclear magnetic resonance (NMR-1H) analysis revealed formation of hydroxyl-terminal groups upon irradiation.