Effect of Acetyl Bromide Treatment on the Ultraviolet Spectra of Lignin Model Compounds

Abstract

The effect on the UV specific absorption coefficients (SACs) at 280 nm was determined for p-Hydroxyphenols, for phenolic and non-phenolic guaiacyl models, phenolic and non-phenolic syringyl compounds. The changes in UV characteristics are discussed in terms of acetylation of hydroxyl groups and the aromatic rings. The results are consistent with the observation that whereas the UV absorption maxima of hardwood lignins have lower SACs and occur at shorter wavelengths than those of softwood lignins, they have similar wavelengths (280 nm) and SACs after AcBr treatment