Preparation of chemically modified lignin and its application in advanced functional materials

Chemically modified lignin refers to a class of high-value products derived from the treatment of industrial lignin using physical, chemical, or biological methods, which alter its structure and properties. The modification of lignin will enhance its thermostability, antioxidant property, adsorbability, antibacterial property, degradability and plasticity, and opens new avenues for its use in biomass utilization, consequently expanding its potential applications. This paper reviews the theoretical foundations and preparation methods of modified lignin, such as amination modification, sulfonation modification, demethylation modification, oxidation modification, graft copolymerization modification and alkylation modification, were reviewed in this paper, with a particular focus on its applications in adhesives, dispersants, drug delivery systems, luminophores, carbon-based energy storage electrodes, and some other areas. Additionally, the paper addresses the challenges and issues faced by modified lignin. This review offers valuable theoretical insights for the green production of modified lignin and its expanded applications.