ABSTRACT
Abstract: Lignin as low-cost sustainable aromatic polymer offers unique opportunity to be used as green polymer feedstock. From the biorenery perspective, some clean lignin isolation processes and high-value applications of the obtained lignins as polymer materials are elaborated in this chapter. However, the heterogeneity of lignin results in the inferior performance compared with petroleum-derived chemicals. This chapter thus also describes in detail the different lignin upgrading strategies to break through the restrictions of lignin heterogeneity. These are classied into three groups: depolymerization, functionalization, and coupled modi-cation with the combination of depolymerization and functionalization. Depolymerization and functionalization of lignin are the most important pathways for lignin upgrading and the coupled modication seems to be more convenient owing to the synchronous cracking
and functionalization of lignin. In addition, some clean and effective lignin depolymerization processes, such as oxidative cracking and green solvent-based cracking, are emphasized as a promising lignin upgrading pathway. Consequently, the effective utilization of lignin as green polymer feedstock offers a signicant way for the value-added applications of lignin.
