Complex Polymer Architectures Using Ring-Opening Metathesis Polymerization: Synthesis, Applications, and Practical Considerations

Nature shows us that complex molecular architectures lead to unique material properties, and these observations have driven polymer scientists to synthesize complex architectures in an effort to discover how topology influences properties in synthetic polymers. In this Perspective, we discuss a variety of complex architectures synthesized using ring-opening metathesis polymerization (ROMP), including multiblock linear polymers, bottlebrush homopolymers and (multi)block copolymers, dendronized polymers, star polymers, and polymer–biomolecule conjugates. Traditional and recently developed synthetic methods, including polymerization-induced self-assembly, copolymerization to create gradient structures, and engineering approaches to making complex topologies using ROMP, are also reviewed. In this context, we highlight emerging applications stemming from these materials, including drug delivery vehicles, nanoscale constructs, and components in light refraction or energy storage, among others. Finally, we conclude with an in-depth discussion on practical considerations in ROMP that enable the highest level of control when synthesizing complex polymer topologies from sterically demanding or otherwise challenging (macro)monomers. Our hope is that this Perspective will guide scientists synthesizing complex polymer architectures toward new and innovative materials with the potential for unique properties and applications.