Title:
Catechol-rich Tree Bark Extracts as Biomass-derived Crosslinkers for Enhanced Gelatin Film Performance
Author(s):
Ponomarenko, J., Pals, M., Radovska, K., Petersone, L., Lauberts, M.
Document(s):
Paper
Poster
Abstract:
This study investigates the potential of aqueous extracts from black alder (Alnus glutinosa) and Baltic pine (Pinus sylvestris) bark as sustainable crosslinking agents to enhance the mechanical properties of gelatin-based biopolymers. Aqueous extraction at 85°C yielded 14.1% and 23.8% (w/w) for alder and pine, respectively. Chemical analysis revealed that black alder extract (BA) was exceptionally rich in catechol moiety-bearing compounds (>0.70 g·g.¹), primarily oregonin, while pine bark extract (P) contained >0.50 g·g.¹ of proanthocyanidins. Crosslinking was achieved via oxidation of catechol moieties into o-quinones, which subsequently formed covalent bonds with gelatin amino groups. Mechanical testing demonstrated that 20% black alder extract produced high-stiffness films (Et: 792 MPa; tensile strength: 40 MPa) due to dense crosslinking. Conversely, 20% pine bark extract induced a unique dual effect, acting as both a crosslinker and an internal plasticizer. These pine-modified films achieved an elongation at break of 449% at low glycerol concentrations (10%), a significant advancement over standard biomass-derived films. However, increasing extract loading beyond 20% led to a sharp decline in mechanical integrity, highlighting a critical threshold for protein matrix stability. These results demonstrate that tree bark extracts can effectively replace synthetic additives to create tunable, bio-based materials ranging from rigid structural films to highly extensible membranes.
Keywords:
forest residues, biopolymers, extraction
Topic:
Biomass Conversion to Biomaterials and Chemicals
Subtopic:
Processes for bio-materials, bio-polymers and bioplastics
Event:
34th European Biomass Conference and Exhibition
Session:
6CV.9.22
Pages:
1065 - 1067
ISBN:
978-88-89407-27-1
Paper DOI:
10.5071/34thEUBCE2026-6CV.9.22
Price:
FREE
