Design Strategies for Branched and Highly Branched Macromolecular Architectures Using Nitroxide-Mediated Living Free-Radical Procedures

Free radical procedures play a dominant role in the synthesis of a wide variety of commodity polymers due to the mild, non-demanding reaction conditions and compatibility with numerous functional groups. However, one of the major disadvantages of free radical polymerizations is the lack of control over macromolecular structure. For example, the polymers obtained are frequently polydisperse and the technique provides poor control over molecular weight, chain ends, and architecture. Many of these shortcomings have recently been overcome using nitroxide mediated 'living' free radical procedures, coupled with well defined unimolecular alkoxyamine initiators. In this report, various strategies for the control of polymeric structure and macromolecular architecture using novel 'living' free radical procedures will be discussed and compared with currently available techniques.