Metal-free ATRP “grafting from” technique for renewable cellulose graft copolymers

Photoinduced metal-free “grafting from” atom transfer radical polymerization (ATRP) has been successfully applied to the fabrication of renewable cellulose graft copolymers with the aid of 2-bromo-2-phenylacetyl ester-modified ethyl cellulose as the macroinitiator. In the presence of an organic-based photoredox catalyst, “grafting from” polymerization of lauryl methacrylate from ethyl cellulose was efficiently activated and deactivated with UV irradiation, resulting in good control over molecular weight. 1H NMR and MALDI-TOF MS confirmed highly preserved Br chain-end functionality. Furthermore, cellulose graft copolymers with a block side chain architecture were successfully prepared through chain extension by metal-free “grafting from” ATRP. We believe that this work will provide a novel approach to design well-defined cellulose graft copolymers and further expand their application fields.