Comparison of Thermal and γ-photon Induced Degradation in Polylactic Acid for Potential as a Solid-State Radiation Detector

Degradation of the biopolymer Polylactic Acid, both thermally and through irradiation will cause physical changes in the material. These changes can be used in applications such as adhesives and sealants or in medical applications, but the primary focus of this study is for use as a solid-state radiation detector. A literature review shows that current research has been focused on thermal and γ-photon degradation in PLA but the physical characteristics such as melting temperature, latent heat of fusion, and composition of molecular bonds have not been compared in the same study. This study focuses on how thermal properties of PLA change in relation to the irradiation counterpart. The major findings of this study are that the melting temperature for thermally degraded samples decreased from 151.5 °C to 130.4 °C , but the melting temperature does not majorly vary with increasing doses up to 110 kGy. The composition of bonds in thermally degraded and irradiated samples experience a change due to the degradation. The latent heat of fusion for thermally degraded and irradiated samples decreases over time, or dose respectively. These characteristics can now be used to further investigate the use of PLA as a solid-state radiation detector, and provide alternative methods for processing PLA to specified physical characteristics