Synthesis of Polythioether Nanoparticles via Thiol-alkene/alkyne Photopolymerization in Miniemulsion

Emulsion-based processes – such as miniemulsion polymerizations – provide well-studied synthetic routes to polymer nanomaterials. Miniemulsion polymerizations are characterized as aqueous dispersions of small, narrowly distributed monomer droplets created through high shear and stabilized against Ostwald ripening/collisional degradation by addition of an appropriate surfactant and costabilizer. In this work, thiol–alkene/alkyne photopolymerization in miniemulsion is demonstrated as a simple, rapid, and one-pot synthetic approach to polythioether nanoparticles with tuneable particle size and clickable functionality. Nanoparticles with mean particle diameters ranging from 45 nm to 200 nm were synthesized through simple modifications to the miniemulsion formulation and processing parameters. Facile access to thiol or alkene/alkyne functional nanoparticles, and subsequent postpolymerization modifications of these functional moieties using thiol-Michael, thiol-yne, and CuAAC click reactions are explored. The strategy is also useful in the synthesis of composite polymer–inorganic nanoparticles such as silver for antimicrobial activity. Ke