Modified lignin nanoparticles for composite and bio-based/Cu packaging applications

Lignocellulosic biomass is an abundant renewable resource with potential for biochemicals and green materials to replace petroleum-based materials.

Lignin is the second most abundant aromatic biopolymer and an underutilized component produced as a by-product in the pulp and paper industry and burned for energy. Lignin can also be used to synthesize bio-based composites by incorporating it into different polymers. For example, PLA is a biodegradable polymer used in food packaging applications.

Lignin has been used as a filler with PLA to enhance thermal stability, UV properties and tensile strength.

However, poor compatibility and aggregation are the main shortcomings for lignin-PLA composites due to the hydroxyl groups present in lignin. Although modification of lignin’s hydroxyl groups has been investigated, current methods are still problematic.

To address these issues, the PACK-NIN project will focus on incorporating lignin nanoparticle (LNP) from kraft, organosolv and soda processes into the PLA matrix to enhance compatibility and bonding interaction.

Due to their higher dispersibility, lower agglomeration and higher surface areas, LNPs are key to improving polymeric composites.

Prior to synthesis of LNPs, novel modifications (oxypropylation and esterification:4-hydroxybenzoic acid) will be employed to enhance lignin’s hydrophobicity.

The modified LNP (MLNP) will be incorporated into a PLA matrix at different weight percentages to investigate mechanical and thermal properties.

Copper nanoparticle will then be introduced into the MLNP/PLA material to evaluate antibacterial activity within the composite.

The PACK-NIN project proposes to develop a sustainable bio-nanocomposite that provides breakthroughs for advancing lignin use in food packaging and other composite applications.

The ER will gain professional maturity and independence through the MSCA program activities, particularly mentoring young researchers, organizing events and managing projects.