Rapid ambient temperature living radical polymerization of methyl methacrylate and styrene utilizing sodium hypophosphite as reducing agent

A facile, safe, and inexpensive reducing agent, sodium hypophosphite (NaH 2 PO 2 ·H 2 O), has been successfully used to perform ambient temperature living radical polymerizations of methyl methacrylate (MMA) and styrene (St). The rapid radical polymerizations were readily obtained at 25°C, i.e., MMA reached a conversion of ca 90% after 2.5 h, and St reached a conversion of ca 80% after 40 h. The polymerizations of MMA and St exhibited excellent living/controlled nature, as evidenced by pseudo first-order kinetics of polymerization, linear evolution of molecular weights with increasing monomer conversions, and narrow molecular weight distributions. The various experimental parameters—ligand, solvent, and molar ratio of NaH 2 PO 2 ·H 2 O to CuSO 4 ·5H 2 O—were varied to improve the control of polymerization, molecular weight, and molecular weight distribution. 1 H NMR analyses and chain-extension reactions confirm the high chain-end functionality of the resultant poly(methyl methacrylate) and polystyrene. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42123.