Fluorous Dispersion Ring-Opening Metathesis Polymerization

초록

We herein report the development of a fluoropolymer dispersion ring-opening metathesis polymerization to polymerize a heavily fluorinated (>60 wt % fluorine) norbornene without the utilization of expensive fluorinated solvents. A fluorinated block copolymer was synthesized and used as a stabilizer, the addition of which allowed for a complete monomer conversion within minutes to yield fluorous polynorbornenes with predetermined molecular weights and low molecular weight distributions (Ds) over a wide range of monomer/catalyst ratios. The products were obtained as spherical particles, the size of which could be controlled over the range of 0.1-7 mu m, and the block copolymer stabilizer was found to occupy a particle surface area of 15.5 nm(2) per molecule. The highly fluorinated polymers were shown to have a very low refractive index, and rheological studies showed a well-defined relationship between zero-shear viscosity and the degree of polymerization, allowing for the determination of critical entanglement molecular weights.

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