Shuttling Catalyst for Living Radical Miniemulsion
Polymerization: Thermoresponsive Ligand for Efficient Catalysis and
Removal
- Publication date
- Publisher
Abstract
In this report, we
demonstrate the use of a thermoresponsive ligand
for the ruthenium-catalyzed living radical polymerization of butyl
methacrylate (BMA) in miniemulsion. A phosphine-ligand-functionalized
polyethylene glycol chain (PPEG) in conjunction with a Cp*-based ruthenium
complex (Cp*: pentamethylcyclopentadienyl) provided thermoresponsive
character as well as catalysis for living polymerization: the complex
migrated from the water phase to the oil phase for polymerization
upon heating and then migrated from the oil to water phase when the
temperature was decreased to quench polymerization. Consequently,
simple treatment (i.e., water washing or methanol reprecipitation)
yielded metal-free polymeric particles containing less than 10 μg/g
(by ICP-AES) of ruthenium residue