@article{
author = "Salah Adeen Embirsh, Hifa and Vuksanović, Marija M. and Mladenović, Ivana O. and Knežević, Nataša and Milošević, Milena and Mijatov, Slavko and Jančić-Heinemann, Radmila and Marinković, Aleksandar",
year = "2024",
abstract = "Materials from green resources boast a low carbon footprint, forming the foundation of
the circular economy approach in materials science. Thus, in this study, waste poly(ethylene
terephthalate) (PET) was subjected to depolymerization using propylene glycol (PG), and
subsequent polycondensation with bio-based maleic anhydride (MA) produced unsaturated
polyester resin (b-UPR). Bio-derived acryloyl-modified Kraft lignin (KfL-A) served as a vinyl
reactive filler in the b-UPR matrix to create b-UPR/KfL-A composites. The structural
characterization of KfL-A and b-UPR involved the use of FTIR and NMR techniques. The
mechanical properties of the newly fabricated composites were assessed through tensile strength,
Vickers microhardness, and dynamic mechanical tests. The addition of KfL-A to the rigid b-UPR
matrix enhanced material flexibility, resulting in less stiff and hard materials while preserving
composite toughness. For instance, incorporating 10 wt.% of KfL-A in b-UPR led to a 17%
reduction in hardness, a 48% decrease in tensile strength, and a 20% reduction in toughness.
Positive environmental impact was achieved by incorporation of 64 wt.% of renewable and
recycled raw material. Analogously prepared b-UPR/KfL composites showed structural
inhomogeneity and somewhat better mechanical properties. Transmission (TEM) and scanning
(SEM) electron microscopies revealed a suitable relationship between mechanical and structural
properties of composites in relation to the extent of KfL-A addition. The UL94V flammability
rating confirmed that flame resistance increased proportionally with the KfL-A addition. Once
deposited in a landfill, these composites are expected to disintegrate more easily than PET, causing less harm to the environment and contributing to sustainability in the plastics cycle.",
publisher = "Elsevier",
journal = "Chemosphere",
title = "Unsaturated polyester resin based composites: A case study of lignin valorisation",
pages = "142144",
doi = "10.1016/j.chemosphere.2024.142144"
}