20.500.12556/DKUM-85902 Kraft lignin/tannin as a potential accelerator of antioxidant and antibacterial properties in an active thermoplastic polyester-based multifunctional material This research focuses on key priorities in the field of sustainable plastic composites that will lead to a reduction in CO2 pollution and support the EU’s goal of becoming carbon neutral by 2050. The main challenge is to develop high-performance polyphenol-reinforced thermoplastic composites, where the use of natural fillers replaces the usual chemical additives with non-toxic ones, not only to improve the final performance but also to increase the desired multifunctionalities (structural, antioxidant, and antibacterial). Therefore, poly (lactic acid) (PLA) composites based on Kraft lignin (KL) and tannin (TANN) were investigated. Two series of PLA composites, PLA-KL and PLA-TANN, which contained natural fillers (0.5%, 1.0%, and 2.5% (w/w)) were prepared by hot melt extrusion. The effects of KL and TANN on the PLA matrices were investigated, especially the surface physicochemical properties, mechanical properties, and antioxidant/antimicrobial activity. The surface physicochemical properties were evaluated by measuring the contact angle (CA), roughness, zeta potential, and nanoindentation. The results of the water contact angle showed that neither KL nor TANN caused a significant change in the wettability, but only a slight increase in the hydrophilicity of the PLA composites. The filler loading, the size of the particles with their available functional groups on the surfaces of the PLA composites, and the interaction between the filler and the PLA polymer depend on the roughness and zeta potential behavior of the PLA-KL and PLA-TANN composites and ultimately improve the surface mechanical properties. The antioxidant properties of the PLA-KL and PLA-TANN composites were determined using the DPPH (2,2′-diphenyl-1-picrylhydrazyl) test. The results show an efficient antioxidant behavior of all PLA-KL and PLA-TANN composites, which increases with the filler content. Finally, the KL- and PLA-based TANN have shown resistance to the Gram-negative bacteria, E. coli, but without a correlation trend between polyphenol filler content and structure. poly (lactic acid) Kraft lignin tannin multifunctionality of PLA composites surface mechanical properties antioxidant/antibacterial activity večnamenskost PLA kompozitov tanin površinske mehanske lastnosti antioksidativno/antibakterijsko delovanje true false true MDPI Angleški jezik Slovenski jezik https://www.mdpi.com/journal/polymers © 2022 by the authors Znanstveno delo 2023-09-18 14:09:30 2023-09-18 14:09:30 2025-03-26 08:32:40 0000-00-00 00:00:00 2022 0 0 18 str. Št. 8, št. članka 1532 Letn. 14 April 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2022-03-03 2022-03-31 2022-04-09 677.017:539.2 104505603 10.3390/polym14081532 2073-4360 Kraft_Lignin_Tannin_as_a_Potentia-Cresnar-2022.pdf Kraft_Lignin_Tannin_as_a_Potentia-Cresnar-2022.pdf 1 C2A94CE5A61CFA85C422135DBB2E0A39 c2e699477cf3205b503f6dfea861d758d902a68749b185bfbfffbac9cfdb89ab a998fb39-561d-11ee-86d1-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=172457 https://www.mdpi.com/2073-4360/14/8/1532 0 b8c4f673-561d-11ee-86d1-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=172458 Fakulteta za strojništvo 0 0 0