Influence of gamma-ray irradiation on polystyrene food container weathering

Conventional plastics, such as polystyrene (PS), are widely used due to their high degradation stability, which makes them suitable for various applications. However, the downside of this property is that it results in the persistence of these plastics in the environment, contributing to plastic pollution. This paper investigated the effects of gamma-ray irradiation on the mechanical, optical, structural, thermal, and morphological properties of PS food containers subjected to natural (NW) and artificial weathering (AW). First, the PS films were exposed to a source of ⁶⁰Co-γ at doses of 0, 10, and 45 kGy, and then they were subjected to NW for 0–190 days and AW for 0–500 h. The mechanical properties of the PS films (tensile strength and elongation at break) were evaluated under NW and AW conditions, revealing an acceleration factor (AF) ranging from 3.8 to 6.2. According to the results, gamma-irradiation had a complex and uneven effect on the physicochemical properties of the weathered PS films. The type of weathering and conditions under which the exposures were performed, in conjunction with the irradiation doses, provided a comprehensive analysis of the effects of gamma-ray irradiation on PS food containers. These results are relevant for extending PS food containers' longevity rather than increasing their degradation.