Synthesis of Novel Rod-Coil Brush Polymers with Conjugated Backbones through Bergman Cyclization

This work reports synthesis of rod-coil brush polymers with rigid conjugated backbone. Grafting through strategy was employed via combination of ring-opening polymerization (ROP) and Bergman cyclization polymerization. Enediyne-containing macromonomers were first synthesized through ROP of caprolactone with dual-functional initiators conceiving free hydroxy groups and dialkynylbenzene moieties. After protection of terminal free hydroxy group of PCL chain and removal of trimethylsilyl protecting group of enediyne unit, the macromonomers were subjected to thermal Bergman cyclization under vacuum. The brush polymers obtained were characterized with GPC and NMR, IR, and UV-vis spectroscopy. The conjugated backbones were revealed as copolymers of naphthalene and indenylmethylene according to NMR analysis.