Gamma irradiation effects on mechanical and thermal properties and biodegradation of poly(3-hydroxybutyrate) based film

ELIDA B HERMIDA; VERÓNICA MEGA,; OXANA YASHCHUK,; VICTOR FERNANDEZ; PATRICIA EISENBERG,; SILVIA MIYAZAKI,

MACROMOLECULAR SYMPOSIA

WILEY

Año: 2008 vol. 263 p. 102 - 113

1022-1360

Their biodegradable properties make polyhydroxyalkanoates (PHA5) idealcandidates for innovative applicatlons. Many studies have been primarlly oriented topoly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-valerate) (PHBV) andafterwards to blends of PHAs with synthtic biodegradable polymers, such aspoly(E-caprolactone) (PCL). Medical and pharmaceutical devices require sterilizationand Gamma irradiation could provide a proper altemative since it assures storage stabilityand microbiological safety. This contribution presents the effect of Gamma Irradiation onthe mechanical and thermal properties and on the biodegradation of PHB, PHBV and acommercial PHB/PCL blend. Samples, prepared by compression moulding, wereirradiated in air at a constant dose rate of 10 kGy/h, from 10 to 179 kGy. Polymerchain scission was assessed by changes in the molecular weight, thermal propertiesand tensile behaviour. The correlation between absorbed dose and changes in themechanical properties and biodegradation is discussed in detall. The optimum doseit guarantee microbiological sterilization without damage of the structure ormeaningful loss of the mechanical properties is also reported.