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 (NaH₂PO₂·H₂O), 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 NaH₂PO₂·H₂O to CuSO₄·5H₂O—were varied to improve the control of polymerization, molecular weight, and molecular weight distribution. ¹H 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.