Abstract:
Lignin is the most abundant renewable aromatic resource in nature, its macromolecular structure is composed of three phenylpropane units (guaiacyl, syringyl and
p-hydroxyphenyl) that connected mainly by ether and carbon-carbon bonds, featuring natural biological activities, hydrophilcity and hydrophobicity, nano-scale adjustability, flexibility in structural modification and biocompatibility. Recent progress on functional materials of lignin is critically discussed based on its structural properties. Firstly, the chemical composition and distribution of lignin in plant cell walls are summarized to elucidating its structural characteristics. Subsequently, recent achievements and challenges on advanced materials based on direct functional application, structural modification, and carbonization are discussed. Finally, the recent progress of lignin used in other fields is briefly summarized, meanwhile, the main points towards future developments and directions in advanced materials of lignin are also highlighted.