Synthesis of polystyrene-grafted cellulose acetate copolymers via nitroxide-mediated polymerization

Cellulose acetate-g-polystyrene (CA-g-PS) grafted copolymers have been synthesized by nitroxide-mediated polymerization (NMP) under homogeneous conditions by using the 1,2-intermolecular radical addition (1,2-IRA) methodology to introduce the SG1-based alkoxyamine BlocBuilder MA (BB) on the polysaccharide backbone. A preliminary study conducted on model sugar-based alkoxyamines proved that whatever the position of the alkoxyamine on the sugar unit, the number of sugar units and the presence of OH groups, one could expect a controlled/living polymerization process. This was confirmed by the graft polymerization of styrene from the BB-modified cellulose acetate backbone with two different grafting ratios (3 and 20%) and different grafted chain lengths (40 000 and 80 000 g mol^-1 targeted Mn). The grafted copolymers were carefully analyzed, in particular, by DOSY NMR to confirm their grafted structure.