Synthesis of Bottlebrush Polymers from ω- Norbornenyl Macromonomers End-Capped with α-Phenyl Acrylate

Abstract

This dissertation focuses on the development of in situ synthesis of ω-norbornenyl macromonomers to prepare bottlebrush polymers. A novel norbornenyl end-capping agent containing α‑phenyl acrylate, NBxPhA [x is 6 (n-hexyl) or 10 (n-decyl)], that provides access to a library of ω-norbornenyl macromonomers through living anionic polymerization was developed. ω-Norbornenyl polystyrene, poly(methyl methacrylate), poly(4- ((trimethylsilyl)ethynyl)styrene), and polystyrene-block-poly(4-((trimethylsilyl)ethynyl) styrene) were synthesized by end-capping reaction of the corresponding living anionic polymers with NBxPhA. Ring-opening metathesis polymerization (ROMP) of the resulting macromonomers produced the well-defined bottlebrush homo-polymers, block copolymers, and core-shell structured polymers. In addition, copper catalyzed azide-alkyne cycloaddition (CuAAC) was employed to endow the resulting bottlebrush polymers with the functionality by installing pyridine pendants which are incompatible with ROMP. The latter parts of this work report on the potential of bottlebrush polymers for applications. The self-assembly of bottlebrush block copolymers composed of polystyrene and poly(methyl methacrylate) side chains produced the lamellar morphology displaying photonic crystals properties. Furthermore, the three-dimensional ordered porous films were constructed by breath figure self-assembly of amphiphilic bottlebrush block copolymers bearing pyridine pendants. The core-shell structured bottlebrush polymers with pyridines in core domains could be used as a template for the preparation of gold nanoparticles-polymer hybrid nanostructures.