(36b) Topology Control of Bottlebrush Polymers

With the development of controlled polymerizations, polymer chemists have enabled the synthesis of more and more complex materials. Bottlebrush polymers are branched polymers with high branching density all originating from a linear backbone and are an example of a material with complex architecture that is accessible via controlled polymerizations. The rigidity of bottlebrush polymers provides a unique way to generate spatially self-organizing materials and have gained much interest in the soft materials community. Thus far bottlebrush polymers have been limited to linear cylindrical shape. Here we present a methodology to construct non-cylindrical bottlebrushes by using a combination of controlled polymerizations to generate a gradient of arm lengths. We implement two orthogonal chemistries, one for arm synthesis and another for backbone synthesis, to generate conical bottlebrushes as a proof of principle. Detailed kinetic studies provide support for the control and specificity of our approach. This methodology results in a material with unprecedented topology and opens a new avenue for more complex materials.