End‐Group Characterization of Poly(acrylic acid) Prepared by Nitroxide‐Mediated Controlled Free‐Radical Polymerization

Summary: A low‐molar‐mass poly(acrylic acid) with a narrow molar‐mass distribution, prepared by SG1 nitroxide‐mediated controlled free‐radical polymerization, was subjected to end‐group analysis to confirm its living nature. 1H and 31P NMR spectroscopy confirmed the presence of the SG1‐based alkoxyamine end group. Furthermore, chain extension with styrene and n‐butyl acrylate demonstrated the ability of the homopolymer to initiate the polymerization of a second block. These results open the door to the synthesis of poly(acrylic acid)‐based block copolymers by direct nitroxide‐mediated polymerization of acrylic acid. Acrylic acid polymerization using an alkoxyamine initiator based on SG1 (N‐tert‐butyl‐N‐(1‐diethyl phosphono‐2,2‐dimethylpropyl) nitroxide resulting in a homopolymer capable of initiating the polymerization of a second block. image Acrylic acid polymerization using an alkoxyamine initiator based on SG1 (N‐tert‐butyl‐N‐(1‐diethyl phosphono‐2,2‐dimethylpropyl) nitroxide resulting in a homopolymer capable of initiating the polymerization of a second block.