In situ generation of nitroxide from alkoxyamines for controlled acrylate polymerization

A general strategy for the controlled nitroxide‐mediated polymerization of acrylates from alkoxyamines without addition of excess free nitroxide is outlined. 2,2‐Dimethyl‐3‐(1‐phenylethoxy)‐4‐phenyl‐3‐azapentane ( 1 ), prepared in one pot by the addition of 1‐phenylethyl radicals to 2‐methyl‐2‐nitrosopropane, is heated prior to the addition of monomer to afford a mixture of alkoxyamine 1 , free nitroxide, and 2,3‐diphenylbutane. With a 30 min preheating period at temperatures up to 125 °C, the kinetics of the subsequent polymerization of n ‐butyl acrylate at 125 °C appear largely unaffected, though the ultimate molecular weight of the polymers is dependent upon the preheating temperature. The poly( n ‐butyl acrylate) samples, that result from this process, have much narrower molecular weight distributions than those which result in the absence of the preheating process.