Mechanical and thermal effects of gamma-irradiation on biodegradable polymeric films based on poly (3-hydroxybutyrate)

VERÓNICA MEGA,; VÍCTOR FERNÁNDEZ,; PATRICIA EISENBERG,; ÉLIDA B. HERMIDA

Estocolmo

Congreso; International Youth Nuclear Congress; 2006

IAEA

Poly(3-hydroxyburate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and blends with other biodegradable polymers are suitable materials for food packaging, because of their good processability, adequate mechanical properties and complete degradation in different environments. Since gamma-irradiation is an alternative method to sterilize packaging with increased storage stability and microbiological safety, the aim of this paper is to study the effect of gamma radiation on the mechanical and thermal properties of films of PHBV and a commercial PHB blend. Films were irradiated at a constant dose rate of 10 kGy/h, up to different doses (from 10 to 179 kGy) in air. Polymer chain scission was assessed by differential scanning calorimetry (DSC) and the tensile properties were measured with an universal testing machine. Dependence of the molecular structure and the mechanical behaviour on the irradiation dose and atmosphere are presented. Their analysis allows determining critical values for the sterilization by gamma irradiation.