Evaluation of the properties poly(3-hidroxybutyrate)/chitosan blend after radiolytic or thermal sterilization

Abstract

In this work was developed PHB/chitosan film with promising application in food and medicine packaging. These films were prepared by the casting solution and after radiolytic or thermal sterilization their properties were evaluated by scanning electron microscopy, tensile testing, differential scanning calorimetry and thermogravimetric analysis. PHB/chitosan films changed their morphology after sterilization processes. Mechanical properties of the blend remained approximately constant after thermal sterilization. But, after irradiation the blends presented brittle. Thermal properties of the blend were changed only for the doses of 50 and 75 kGy, in which case was observed a reduction in the crystallization enthalpy value, the degree of crystallinity, relative crystallinity and crystallization rate of the blend. It was observed thermal degradation of the PHB films and blends, before and after sterilization processes presented a single stage (250-300 °C).

Keywords:
polymers blends; thermal sterilization; radiolytic sterilization; PHB; chitosan