Polynorbornene latex synthesis by UV-triggered Ring-Opening Metathesis Polymerization in miniemulsion

An innovative route based on a novel photo-latent ROMP initiator has been explored to synthesize polynorbornene latex particles in miniemulsion. Operation conditions were strongly improved by the use of an annular LED photo-reactor, increasing the uniformity of radiation distribution and enabling to control atmosphere and stirring throughout irradiation. Several parameters (droplet size, irradiance, pre-catalyst structure) were studied in order to improve the monomer conversion profiles, which eventually led to the production of latex with high norbornene conversion (>90%) and 10% solids content. Particular attention was paid to the polymer microstructure, which was found to be highly dependent on the type of initiation mechanism.