Influence of chain length in protic ionic liquids on physicochemical and structural features of lignins from sugarcane bagasse

•Increase of the PILs cation chain length resulted in enhanced depolymerization.•Ionicity of the protic ionic liquid showed a stronger influence on lignin dissolution.•Lignin extracted by [Eti][Mal] showed possibly the most preserved structure.•Lignins extracted by protic ionic liquids can promote industrial applications.