Enhanced UV-C resistance of 3D-printed poly(lactic acid)/glass fiber composites: Structural stability and sustainable design

The development of molded products using biodegradable biomass plastics such as polylactic acid (PLA) has been actively promoted in order to reduce environmental problems caused by petroleum-derived plastics. However, because biomass plastics are brittle and have low thermal stability, there is a need to develop fiber-reinforced composites with weather and heat resistance. In this study, PLA/glass fiber (GF) composite moldings are fabricated using a 3D printer, and the effects of UV-C irradiation on PLA/GF composites were evaluated by irradiating them with UV-C for 0 −14d. The results suggest that although the surfaces of the PLA and PLA–GF composite are oxidized, the degradation of PLA molecules by UV-C is reduced as the GF content increases. That is, compared to neat PLA, the decrease in the melting point, tensile modulus and strength of the PLA/GF composite material was suppressed. We demonstrated that glass fibers have the potential not only as a reinforcing material but also as a UV-absorbing material by making good use of the property that glass does not allow short-wavelength UV rays to pass through.