UV Protective, Antioxidant, Antibacterial and Compostable Polylactic Acid Composites Containing Pristine and Chemically Modified Lignin Nanoparticles

E. CAVALLO; X. HE; F. LUZI; F. DOMINICI; P. CERRUTTI; C. BERNAL; M.L. FORESTI; L. TORRE; D. PUGLIA

MOLECULES

MOLECULAR DIVERSITY PRESERVATION INTERNATIONAL-MDPI

Lugar: Basel; Año: 2021 vol. 26 p. 126 - 130

1420-3049

Polylactic acid (PLA) films containing 1 wt % and 3 wt % of lignin nanoparticles (pristine(LNP), chemically modified with citric acid (caLNP) and acetylated (aLNP)) were prepared byextrusion and characterized in terms of their overall performance as food packaging materials.Morphological, mechanical, thermal, UV?Vis barrier, antioxidant and antibacterial properties wereassayed; appropriate migration values in food simulants and disintegration in simulated compostingconditions were also verified. The results obtained indicated that all lignin nanoparticles succeededin conferring UV-blocking, antioxidant and antibacterial properties to the PLA films, especially at thehigher filler loadings assayed. Chemical modification of the fillers partially reduced the UV protectionand the antioxidant properties of the resulting composites, but it induced better nanoparticlesdispersion, reduced aggregates size, enhanced ductility and improved aesthetic quality of the filmsthrough reduction of the characteristic dark color of lignin. Migration tests and disintegration assaysof the nanocomposites in simulated composting conditions indicated that, irrespectively of theirformulation, the multifunctional nanocomposite films prepared behaved similarly to neat PLA.