Structural Stability of Photodegradable Poly( L -Lactic Acid)/pe/tio 2 Nanocomposites Through TiO 2 Nanospheres and TiO 2 Nanotubes Incorporation

Photodegradation of PLA/PE, PLA/PE/TiO 2 nanospheres and PLA/PE/TiO 2 nanotubes was obtained under simulated sunlight. The nanocomposites were analyzed by infrared spectroscopy, scanning electron microscopy and tensile-deformation measurements. TiO 2 nanospheres and TiO 2 nanotubes were found to present different effects on the crystallinity of PLA and a straight correlation between structural organization and photostability was observed. According to the results, TiO 2 promotes the degradation of PLA and PE, affecting the organizational level of the polymers. By adding TiO 2 nanoparticles to the PLA/PE films, vibration modes characteristic of degradation products were promptly observed and the lifetime of the polymer decreased when compared to the PLA/PE without TiO 2 nanoparticles. Mechanical measurements showed an improvement of the mechanical properties when adding the TiO 2 nanoparticles.