Design and characterization of functional TiO2-lignin fillers used in rotational molded polyethylene containers

Karol Bula; Patryk Jędrzejczak; Dawid Ajnbacher; Maurice N Collins; Łukasz Klapiszewski

doi:10.1016/j.ijbiomac.2023.125626

Design and characterization of functional TiO₂-lignin fillers used in rotational molded polyethylene containers

Int J Biol Macromol. 2023 Aug 15:246:125626. doi: 10.1016/j.ijbiomac.2023.125626. Epub 2023 Jun 29.

Authors

Karol Bula¹, Patryk Jędrzejczak², Dawid Ajnbacher³, Maurice N Collins⁴, Łukasz Klapiszewski⁵

Affiliations

¹ Institute of Material Technology, Faculty of Mechanical Engineering, Poznan University of Technology, PL-60965 Poznan, Poland. Electronic address: karol.bula@put.poznan.pl.
² Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, PL-60965 Poznan, Poland.
³ Institute of Material Technology, Faculty of Mechanical Engineering, Poznan University of Technology, PL-60965 Poznan, Poland.
⁴ School of Engineering and Bernal Institute, University of Limerick, Ireland; Advanced Materials and BioEngineering Research Centre (AMBER), University of Limerick, Ireland.
⁵ Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, PL-60965 Poznan, Poland. Electronic address: lukasz.klapiszewski@put.poznan.pl.

PMID: 37392911
DOI: 10.1016/j.ijbiomac.2023.125626

Abstract

In this study, new TiO₂-lignin hybrid systems were synthesized and characterized by various methods, including non-invasive backscattering (NIBS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), elemental analysis (EA) and zeta potential analysis (ZP). The weak hydrogen bonds between the components, as shown on FTIR spectra, proved the production of class I hybrid systems. TiO₂-lignin systems were found to display good thermal stability and relatively good homogeneity. These newly designed hybrid materials were used to produce functional composites via rotational molding in a linear low-density polyethylene (LLDPE) matrix at 2.5 % and 5.0 % loading by weight of the fillers, namely, TiO₂, TiO₂-lignin (5:1 wt./wt.), TiO₂-lignin (1:1 wt./wt.), TiO₂-lignin (1:5 wt./wt.) and pristine lignin, creating rectangular specimens. The mechanical properties of the specimens were measured via compression testing and by low-energy impact damage testing (the drop test). The results showed that the system containing 5.0 % by weight of TiO₂-lignin (1:1 wt./wt.) had the most positive effect on the container's compression strength, while the LLDPE filled with 5.0 % by weight of TiO₂-lignin (5:1 wt./wt.) demonstrated the best impact resistance among all the tested composites.

Keywords: Biopolymer containers; Hybrid materials; Kraft lignin; Rotational molding; Titanium dioxide.