Tailoring of water-soluble cellulose-g-copolymers in homogeneous medium using single-electron-transfer living radical polymerization

Cellulose-graft-polyacrylamide and cellulose-graft-poly(N,N-dimethylacrylamide) copolymers were prepared by single-electron-transfer living radical polymerization (SET-LRP) in homogeneous medium. Cellulose macroinitiators for SET-LRP, with different numbers of initiating sites along the cellulose backbone, were successfully synthesized by direct acylation of cellulose with 2-bromoisobutyryl bromide in LiCl/dimethylacetamide. Dynamic light scattering revealed that cellulose macroinitiator molecules in dimethylsulfoxide (DMSO) exist primarily as individual chains with a certain amount of intermolecular aggregates. SET-LRP of acrylamide and N, N-dimethylacrylamide with the cellulose macroinitiators was carried out in DMSO solution. Formation of cellulose-graft-copolymers was confirmed using attenuated total reflectance Fourier transform infrared, H-1 NMR and C-13 NMR spectroscopy, and the products were water-soluble. High content of poly(N, N-dimethylacrylamide) in the copolymers enhanced the thermal stability relative to that of cellulose. Scanning electron microscopy studies of cellulose-based particles formed from the copolymers using the aerosol flow reactor method revealed spherical nanoscale structures. (C) 2011 Society of Chemical Industry