Synthesis and self-assembly of brush block polymers with low T_g side chains

Abstract

Brush block copolymers display unique properties due to their dense functionality, low entanglement, and rapid self-assembly. Using ruthenium-mediated ring-opening metathesis polymn. (ROMP) of norbornenefunctionalized macromonomers, our group has harnessed these unique properties of the brush polymer architecture to access highly-ordered nanostructures. However, the use of low T_g side chains in brush block copolymers remains relatively unexplored. Herein, we describe the synthesis of brush block copolymers featuring side chains with T_gs below room temp., including samples with grafted poly(dimethylsiloxane) (PDMS), poly(trimethylene carbonate) (PTMC), and poly(ethylene oxide) (PEO) blocks. These materials can be annealed at relatively low temps. to form photonic crystals that reflect visible to near-IR light. The self-assembly of these copolymers has been investigated by SAXS and UV-vis spectroscopy.