Kinetics of atom transfer radical polymerization of methyl methacrylate initiated by cellulose chloroacetate in BMIMCl

Abstract

The kinetics of atom transfer radical polymerization(ATRP) of methyl methacrylate(MMA) initiated by cellulose based macroinitator, cellulose chloroacetate, performed in ionic liquid(1-N-butyl-3-methylimidazolium chloride, BMIMCl), dimethyl sulfoxide(DMSO) and dimethyl formamide(DMF) were respectively studied in detail. The polymerizations were carried out under homogeneous conditions with CuBr as catalyst and 2,2'-bipyridine(bpy) as ligand. The dependences of the rate of polymerization on solvent, temperature, monomer/initiator ratio and catalyst/ligand ratio were presented. Plots of ln((M)0/(M)t) vs. time and molecular weight vs. conversion showed a linear dependence, indicating a constant number of propagating species throughout the polymerization as well as a negligible contribution of termination or transfer reactions. On the basis of an Arrhenius plot, the apparent energy of activation(ΔEa app ) for ATRP of MMA in BMIMCl was 16.6 kJ/mol which is much lower than that in diphenyl