Journal
POLYMERS
Volume 12, Issue 1, Pages -Publisher
MDPI
DOI: 10.3390/polym12010175
Keywords
lignin; catalyst; urea-formaldehyde resin; adhesive
Categories
Funding
- Jiangsu Key Laboratory for Biomass Energy and Materials [JSBEM-S-201901]
- National Key R&D Program of China [2017YFE0106800]
- National Natural Science Foundation of China [31890774]
Ask authors/readers for more resources
In this study, a lignin-based polyacid catalyst was synthesized via two steps to enhance water resistance of urea-formaldehyde (UF) resins. The first steps involved a hydroxymethylation reaction to increase the hydroxyl content in lignin. Then, hydroxymethylated lignins were reacted with maleic anhydride to form maleated lignin-based polyacids. The acid groups were expected to function as acid catalysts to catalyze the curing process of UF resin. In order to elucidate the structural variation, 3-methoxy-4-hydroxyphenylpropane as a typical guaiacol lignin structural unit was used as a model compound to observe the hydroxymethylation and the reaction with maleic anhydride analyzed by H-1 and C-13 NMR. After the structural analysis of synthesized lignin-based polyacid by FTIR and C-13 NMR, it was used to produce UF resin as an adhesive in plywood and medium density fiberboard (MDF) production, respectively. The results showed that when the addition of lignin-based polyacid was 5% in plywood, it could effectively improve the water resistance of UF resins as compared to commercial additive NH4Cl. It also exhibited a lower formaldehyde emission. Like plywood, lignin-based catalysts used in medium density fiberboard production could not only maintain the mechanical properties, but also inhibit the water adsorption of fiberboards.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available