High-Performance Polylactic Acid Materials Enabled by TiO2–Polydopamine Hybrid Nanoparticles

Poor ultraviolet (UV) stability of polylactic acid (PLA) partially restricts its applications under atmospheric conditions. Titanium dioxide (TiO2) is a common and widely used UV-shielding agent, but detrimental effects often exists on the properties of polymers. In this study, we used polydopamine (PDA) to construct TiO2–PDA hybrid nanoparticles. The introduction of PDA can greatly reduce oxygen vacancies in TiO2, so as to better maintain the stability of the polymer matrix. TiO2–PDA hybrid nanoparticles were synthesized through simple steps and composited with PLA to prepare PLA/TiO2–PDA nanocomposites (noted as PLA/TP). The established PLA/TP films show excellent UV-shielding performance without sacrificing transparency (the transmittance at 550 nm is 85.7%). What’s more, with 0.2 wt % nanoparticles added, the nanocomposite films have a good combination of strength and toughness. The performance improvement of PLA will broaden its application fields, making environmental materials have a wider range of uses and longer service life.