Synthesis of peptide–vinyl polymer multiblock hybrids by nitroxide-mediated polymerization: breaking the limitations of monomer compatibility

Significant efforts have been dedicated toward designing conjugated sequence-controlled peptides and synthetic vinyl polymers as a new class of polymeric materials with ordered structures and specific biofunctions. The creation of novel synthetic strategies that enables the precise incorporation of multiple tailored peptides along a vinyl polymer backbone remains highly challenging. Herein, we report a useful method for preparing multiblock architectures composed of alternately aligned sequential peptides and various vinyl polymers through nitroxide-mediated polymerization (NMP). A new cyclic oligopeptide was developed containing a 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO)-derived alkoxyamine bond in the framework. Controlled radical polymerization in a homogeneous liquid phase using this peptide initiator successfully provided a well-defined multiblock hybrid polymer in one step, in which chain extension and multimerization proceeded simultaneously. This method was applied to the polymerizations of a wide range of vinyl monomers, including styrene, acrylamides, acrylates and acrylonitrile. Expanding the compatibility of monomers with this approach is valuable for constructing complex multiblock architectures with structural and functional diversity.