Fabrication of dual-functional cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives by RAFT-assisted Pickering emulsion polymerization for self-healing application

Polymeric coatings are easy to be damaged by harsh environment condition, which causes cracks and loss of function. Inspired by the natural self-healing phenomenon, we successfully synthesized dual-functional cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives by RAFT-assisted Pickering emulsion polymerization. The amphiphilic and photo-responsive copolymer, PDMAEMA-b-PGMA-b-P(HFBA-co-VBMC) was synthesized by RAFT process, followed by characterization using FT-IR, SEC, 1H NMR and UV-vis. The cellulose nanocrystals were modified by the copolymer, which were confirmed via XPS, UV-vis and so on. Besides, the droplet size of Pickering emulsion gradually increased and the creaming layer gradually decreased as the pH value increased. The TEM result showed that the modified cellulose nanocrystals were effectively anchored on the outside of latex particles. The size of the spherical-like latex particles increased and the stability of latex particles was worse with increasing pH value. Finally, the finished fabric had excellent water resistance due to the combination of micro-or nanoscale hierarchical structure and low surface energy. Moreover, the latex film exhibited excellent repeatability of self-healing ability. The fabric coating achieved the intrinsic and superficial dual-functional self-healing performance by the reversible [2 + 2] cycloaddition of coumarin groups. This strategy provides a powerful guide for preparing the high-performance waterborne fluorinated polyacrylate coating.

Automated summary

Inspired by natural self-healing phenomenon, we synthesized dual-functional cellulose nanocrystals/fluorinated polyacrylate containing coumarin derivatives via RAFT-assisted Pickering emulsion polymerization. Characterization using FT-IR, SEC, 1H NMR, and UV-vis confirmed the amphiphilic and photo-responsive copolymer PDMAEMA-b-PGMA-b-P(HFBA-co-VBMC). The modified cellulose nanocrystals were effectively anchored on the outside of latex particles, resulting in increased droplet size and decreased stability with increasing pH value in the Pickering emulsion. Moreover, the fabric coating exhibited excellent water resistance and repeatability of self-healing ability due to the combination of micro-or nanoscale hierarchical structure and low surface energy.