Graft modification of crystalline nanocellulose by Cu(0)-mediated SET living radical polymerization

Crystalline nanocellulose (CNC) was grafted with poly(methyl acrylate) (PMA) to yield modified CNC that is readily dispersed in a range of organic solvents [including tetrahydrofuran, chloroform, dimethylformamide, and dimethyl sulfoxide (DMSO)], in contrast to native CNC which is dispersible primarily in aqueous solutions. First, a CNC macroinitiator with high bromine initiator density was prepared through a 1,1-carbonyldiimidazole-mediated esterification reaction in DMSO-based dispersant. MA was then grafted from the CNC macroinitiator through SET living radical polymerization (LRP) at room temperature using Cu(0) (copper wire) as the catalyst. The LRP grafting proceeded rapidly, with approximate to 30% monomer conversion achieved within 30 min, yielding approximately six times the mass of PMA with respect to CNC macroinitiator. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2800-2808