Novel Electrical Insulation Materials – Photodegradation Endurance of 3D Printed Polylactic Acid

The degradation of plastic materials induced by solar radiation can limit their use in outdoor applications. Therefore, we aimed to find a relationship between the photodegradation of 3D printed polylactic acid (PLA) and its electrical and thermomechanical properties. In the first stage, the printing settings were optimized with regard to the dielectric strength of samples. Afterward, the sets of printed specimens were exposed to UV light of different spectrum and duration. UV gas-discharge lamps with spectral peaks at 254 and 385 nm were used as intense UV light sources; the individual exposure times were chosen as 6, 12, 24, 48, and 96 hours. Subsequently, the dielectric strength of each set was evaluated, and thermomechanical analyses were performed. Although the irradiation at 254 nm caused substantial degradation of PLA, it did not remarkably affect its dielectric strength. Nonetheless, both sources of UV light caused a considerable brittleness that might be the limiting factor for the outdoor application of PLA.