Title:
Chemical Characterization and Reactivity Studies of Various Industrially Obtained Lignins for their Potential Use in Lignin-phenol-formaldehyde Resin Production
Author(s):
Lauberts, M., Rizikovs, J., Pals, M.
Document(s):
Paper
Poster
Abstract:
The most widely used binder for glued wood composites is phenol-formaldehyde (PF) resin. Considering the chemical properties of PF resin raw materials: phenol and formaldehyde, their sources (fossil) and the impact on the environment, it is necessary to think about renewable, cheaper, and environmentally friendly raw materials for their production. Lignin, a bio-polyphenol, is a complex and amorphous substance formed through the polymerization of three phenylpropane monomers: sinapyl, coniferyl, and coumaryl alcohols and its structures have similarity to that of phenol. Lignin consists of various functional groups, they can react with aldehydes or phenol, similar to the process of phenol reacting with formaldehyde to produce phenolic resin adhesives. This suggests the potential of lignin to serve as a partial substitute for phenol or formaldehyde in the preparation of wood adhesives and will additionally reduce the negative impact on the environment and people. This study investigates the correlation between the effect of the chemical composition of industrially obtained lignins (Kraft lignin, organosolv lignin, hydrolysis lignin and also enzymatic hydrolysis lignin) on their reactivity with paraformaldehyde (PFA) with the aim to find out the influencing factors for the production of lignin-based phenol formaldehyde (LPF) resins with the best physico-chemical properties. The influence of their chemical composition on the reactivity showed that the lignin samples with the highest lignin content and purity showed the best reaction with PFA. Kraft lignin with the highest lignin content of 86% and a high amount of phenyl derivatives in the lignin structure showed the lowest temperature maximum (121.5 °C) at the ratio lignin : PFA (1:2) and lignin : NaOH (10:1) compared to another samples. The results obtained in the laboratory and the main conclusions about the suitability of lignins for the production of LPF resin were also confirmed by experiments in resin production processes under upscale conditions.
Keywords:
lignin, sustainability, resin, biobased products, biobased economy
Topic:
Biomass Conversion to Bio-Based Products and Chemicals
Subtopic:
Processes for bio-based chemicals and materials
Event:
31st European Biomass Conference and Exhibition
Session:
6BV.2.33
Pages:
1089 - 1093
ISBN:
978-88-89407-23-3
Paper DOI:
10.5071/31stEUBCE2023-6BV.2.33
Price:
FREE
