Kraft Lignin/Tannin as a Potential Accelerator of Antioxidant and Antibacterial Properties in an Active Thermoplastic Polyester-Based Multifunctional Material
Artikel i vetenskaplig tidskrift, 2022

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)

Antioxidant/antibacterial activity

Tannin

Kraft lignin

Multifunctionality of PLA composites

Surface mechanical properties

Författare

Klementina Pusnik Cresnar

Univerza v Mariboru

Alexandra Zamboulis

Aristotelio Panepistimio Thessalonikis

Dimitrios N. Bikiaris

Aristotelio Panepistimio Thessalonikis

Alexandra Aulova

Univerza V Ljubljani

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Lidija Fras Zemljic

Univerza v Mariboru

Polymers

2073-4360 (eISSN)

Vol. 14 8 1532

Ämneskategorier

Polymerkemi

Polymerteknologi

Annan kemi

DOI

10.3390/polym14081532

PubMed

35458280

Mer information

Senast uppdaterat

2022-06-08