Dissolution and resourcfulization of biopolymers in ionic liquids

Cellulose, starch, chitosan, β-cyclodextrin, lignin and proteins are the most abundant elements in the universe with excellent properties, such as good biodegradability and biocompatibility, thus have gained tremendous interest in many fields. Unfortunately, these biopolymers suffer greatly from the solubility in neutral or basic solutions, insufficient mechanical properties, brittleness, and also have other drawbacks. Ionic liquids (ILs) are a kind of greener solvents for biopolymers, owning to their excellent physical–chemical properties. ILs also provide a premise condition for the homogeneous reaction of biopolymers; improve the utilization value of biopolymer. In this paper, the dissolution, regeneration and modification of cellulose, starch, chitosan, lignin and protein in ionic liquids are reviewed.