Lignin Esters for Use in Unsaturated Thermosets: Lignin Modification and Solubility Modeling
Top Cited Papers
- 7 June 2005
- journal article
- Published by American Chemical Society (ACS) in Biomacromolecules
- Vol. 6 (4), 1895-1905
- https://doi.org/10.1021/bm0500345
Abstract
Kraft lignins from hardwood and softwood were esterified with several anhydrides to alter their solubility behavior in nonpolar solvents, such as styrene-containing thermoset resins. The esterification reaction was facile, it reduced the amount of waste products, and can be readily scaled up. Increasing the carbon chain length on the ester group improved the solubility of kraft lignin in nonpolar solvents, with butyrated lignin being completely soluble in styrene. Esterification with unsaturated groups such as methacrylic anhydride, improved the solubility to a lesser extent than the saturated analogues. The solubility behavior of the modified lignin was described using the Flory−Huggins solubility theory, combined with the predictive method of Hoy. The main goal to obtain a styrene soluble kraft lignin that could be used in unsaturated polyesters and vinyl esters was achieved with fully butyrated kraft lignin and a butyrated/methacrylated kraft lignin. The solubility of the latter is governed by the butyrate/methacrylate ratio. The reaction rate constants for the butyration and methacrylation reactions were also determined and the aromatic hydroxyl groups were found to be consistently three times more reactive than the aliphatic ones.Keywords
This publication has 42 references indexed in Scilit:
- Lignin-filled polyolefinsJournal of Applied Polymer Science, 1999
- A study of chemical structure of soft and hardwood and wood polymers by FTIR spectroscopyJournal of Applied Polymer Science, 1999
- Synthesis of Lignin /Epoxy Resins in Aqueous Systems and Their PropertiesHolzforschung, 1997
- Molecular Weight Distribution of (Semi-) Commercial Lignin DerivativesJournal of Wood Chemistry and Technology, 1993
- Light scattering of acetylated ligninJournal of Applied Polymer Science, 1992
- Lignin. 24. Ultrafiltration and light-scattering evidence for association of kraft lignins in aqueous solutionsMacromolecules, 1988
- 13C-NMR Spectra of Kraft LigninsHolzforschung, 1983
- Characterization of aspen exploded wood ligninCanadian Journal of Chemistry, 1982
- Source of selectivity in the quantitative determination of alcohols by acylation with cyclic anhydridesAnalytical Chemistry, 1975
- The Solvent Properties of Liquids and Their Relation to the Solubility, Swelling, Isolation and Fractionation of LigninJournal of the American Chemical Society, 1952