Recent Studies on the Preparation and Application of Ionic Amphiphilic Lignin: A Comprehensive Review

Abstract

As the second most abundant natural polymer after cellulose, lignin has received considerable attention recently due to its reproducibility, safety, and biodegradability. Studies are now focusing on the development of new lignin applications to replace petroleum-based chemicals. Unfortunately, lignin has several inherent problems, such as poor water solubility and a tendency to agglomerate. However, after chemical modification, lignin can gain new functions through the introduction of new functional groups. For example, amphiphilic lignin is a polymer that is soluble in both water and organic solvents. Amphiphilic lignin polymers can be divided into anionic, cationic, and anionic−cationic amphoteric lignin-based polymers, according to the ions contained in their molecular structure. Amphiphilic lignin polymers also have a wide range of applications in various industrial fields and can be used as wetting agents, detergents, controlled release fertilizers, adsorbents, and emulsifiers. Thus, this article reviews research progress on the synthesis and applications of amphiphilic lignin-derived polymers over the past 10 years, providing a theoretical reference for the utilization of high-added-value and high-performance lignin.

Bioresource Upgrade for Sustainable Energy, Environment, and Biomedicine

“…Although there is potential for direct industrial application, unmodified lignin can only be incorporated in small amounts due to its weak mechanical properties. On the other hand, lignin can be chemically modified to be used as a starting material for polymer synthesis or for conversion into chemicals and fuels [75][76][77][78]. There are four different ways to chemically modify lignin: (1) lignin depolymerization or fragmentation, using lignin as a carbon source or cleaving it into small fragments containing aromatic rings; (2) modification of lignin by synthesis of new chemically active sites; (3) chemical modification of the hydroxyl groups presents in the lignin structure; and (4) production of graft copolymers.…”

Novel Lignin‐Functionalized Waterborne Epoxy Composite Coatings with Excellent Anti‐Aging, UV Resistance, and Interfacial Anti‐Corrosion Performance

“…[23] As a green polymer with amphiphilic (hydrophilic and lipophilic) structure, lignin has good dispersing properties, and its application as a green dispersant in the field of anti-corrosive coatings has been reported in a few works. [24][25][26] Wang et al [9] exploited the non-covalent interaction between lignin and graphene to effectively improve the dispersion and stability of composites in aqueous epoxy. In our previous study, we found that sodium lignosulfonate (LS) can provide certain corrosion inhibition properties for carbon steel.…”