Arm-first synthesis of hyperbranched-core star polymers via copper-catalyzed azide-alkyne cycloaddition

A general method for the arm-first synthesis of star polymers through a formal A2 + B3 step-growth process is introduced. The synthesis relies on copper-catalyzed azide-alkyne cycloaddition (CuAAC) of N3-C(CR2)C-N3 macromonomers with a trifunctional alkyne crosslinker, and is enabled by the special mode of reactivity of 1,3diazides in CuAAC. A variety of synthetic conditions were systematically evaluated, and effects of macromonomer size and feed ratio on the product structures have been investigated. Due to functional group tolerance of CuAAC, the presented methodology has a broad scope and can be extended to other macromonomers.

Automated summary

A general method for the arm-first synthesis of star polymers is introduced, which involves a formal A2 + B3 step-growth process. The technique utilizes copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between N3-C(CR2)C-N3 macromonomers and a trifunctional alkyne crosslinker. By systematically evaluating various synthetic conditions, the effects of macromonomer size and feed ratio on the product structures have been investigated. The broad scope of this methodology, enabled by the functional group tolerance of CuAAC, allows for its extension to other macromonomers.