The differences between acid–base and redox properties of phenolic structures of coniferous and deciduous native lignins

Abstract

Natural lignins are one of the most widespread biopolymers. The main active centers in the lignin macromolecules are phenolic hydroxyl groups. They form lignin macromolecules reactivity. The lignin is considered as a natural polyphenol. The main characteristics of the lignin reactivity are their acid–base and redox properties. Acid–base properties of lignins are characterized by pKa values of basic types of phenolic structures. The redox properties are characterized by effective oxidation potential and the Gibbs energy of the phenolic structures. This paper studies the acid–base and redox properties of the phenolic structures of coniferous and deciduous natural lignins. The authors analyze the representative slightly altered preparations of dioxane lignin extracted from coniferous wood (spruce, common juniper) and deciduous wood (common aspen). The study reveals the differences in the reaction properties of coniferous and deciduous lignins due to their functional nature and macromolecular properties.