Effects of Gamma Irradiation Upon the Mechanical and Chemical Properties of 3D-Printed Samples of Polylactic Acid

Abstract

3D printing offers the opportunity to design and make replacement parts to exacting specifications when needed. This is particularly helpful for space applications where stand-alone replacement mechanisms are required. Samples of 3D-printed polylactic acid (PLA) were subjected with up to 200 kGy of gamma radiation from a Cobalt-60 irradiator. The mechanical responses to destructive testing were successfully modeled with a combination of linear and exponential functions and may be understood given the underlying chemical changes due to said radiation exposures. We find that for doses up to 50 kGy, the performance of 3D-printed PLA is largely unaffected, which is beneficial for applications in space and in medicine. At larger doses, it appears that decomposition processes win out over cross-linking, which may aid in the degradation of PLA in waste streams.