Strategies for inhibition of cellulose degradation in valorization of lignocelluloses for functional materials fabrication

Abstract

Synthetic fibers on the market are mainly derived from fossil resources. The diminishing of this kind of resources and the accompanied environmental issues have stimulated interest in the utilization of renewable materials. Cellulose, widely available in lignocelluloses, is a kind of abundant and renewable biopolymer in nature. It has been ascending as a promising feedstock for the manufacture of functional materials to replace fossil-based synthetic fibers. Pretreatment of lignocelluloses is a requisite step for the production of cellulosic materials since this biopolymer is embedded in the matrix composed of lignin and hemicellulose in the plant cell wall. However, cellulose degradation usually occurs in the pretreatment and the subsequent material preparation processes, affecting properties of the fabricated materials. In this paper, we have provided a comprehensive review of the strategies to inhibit cellulose degradation in valorization of lignocelluloses for functional materials fabrication. It is demonstrated that the interactions between the solvent (including organics, ionic liquid, deep eutectic solvent, etc.) and cellulose closely relates to degradation. And too strong interactions would lead to degradation of this biopolymer, resulting in decrease of the polymerization degree of cellulose and thus inferior properties (including mechanical one) of the corresponding materials. Introducing additives, co-solvents, radical scavengers or selection of proper solvents would affect the interactions between the solvent and cellulose to inhibit degradation, facilitating the fabrication of functional materials with excellent property. The challenges and future perspective (e.g., understanding the inhibition mechanism from molecular level) in the development of more efficient technologies to prevent cellulose degradation were also highlighted. This paper could provide guidance for design of systems to obtain cellulosic materials with excellent properties, and more people are encouraged to engage in this field to promote relevant progress.