Effect of Gamma Irradiation on the Mechanical Properties and Thermal Properties of Poly(3-Hydroxybutyrate-Co-3-hydroxyhexanoate)(PHBHHx) Based Films

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a naturally sourced polymer with good biocompatibility and potential applications in biomedical field after sterilization. Radiation sterilization technology has been extensively applied on medical products. However, for polymer-based biomedical materials, gamma irradiation can cause random chain scission on the polymer backbone. In this paper, we studied the effect of gamma irradiation on the mechanical and thermal properties of PHBHHx. The tensile strength and fracture strain of PHBHHx decreased after irradiation, while the brittleness increased after irradiation. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results showed that the melting temperatures of irradiated PHBHHx are lower than the non-irradiated films, but the irradiated specimen shows a higher decomposition temperature than non-irradiated PHBHHx.