Self-Healing Properties of Lignin-Containing Nanocomposite: Synthesis of Lignin-graft-poly(5-acetylaminopentyl acrylate) via RAFT and Click Chemistry

Abstract

Lignin can be an important source of synthetic commodity materials owing to its abundance in nature and low production cost. The current use of lignin as a raw material, however, is very limited and focused only on cheap and poorly defined nonfunctional materials. Herein we report a new lignin-containing functional polymer, lignin-graft-poly(5-acetylaminopentyl acrylate) (lignin-graft-PAA), which has been prepared by the covalent linkage of chemically modified lignin with PAA, which is an end-group functionalized polymer. This work makes two significant advances in the study of lignin-containing polymers: (1) lignin-graft-PAA is the first example of lignin being modified by a polymer with sophisticated structure, and (2) lignin-graft-PAA shows a special performance, autonomic self-healing properties, which have not yet been seen in lignin-containing polymers. The key synthetic step in this process utilizes a copper-catalyzed azide–alkyne cycloaddition or “click” reaction in order to join together the lign...