Synthesis and characterization of poly(ethylene glycol) bottlebrush networks via ring-opening metathesis polymerization

Herein it is reported how the overlap concentration (C*) can be used to overcome crosslinking due to diol impurities in commercial poly(ethylene glycol) (PEG), allowing for the synthesize of bottlebrush polymers with good control over molecular weight. Additionally, PEG-based bottlebrush networks are synthesized via ring-opening metathesis polymerization, attaining high conversions with minimal sol fractions (<2%). The crystallinity and mechanical properties of these networks are then further altered by solvent swelling with phosphate buffer solution and 1-ethyl-3-methylimidazolium ethyl sulfate/dichloromethane cosolvents. The syntheses reported here highlight the potential of the bottlebrush network architecture for use in the rational design of new materials.