Recyclable cross-linked hydroxythioether particles with tunable structures via robust and efficient thiol-epoxy dispersion polymerizations

The highly efficient base-catalyzed thiol-epoxy reactions were exploited in dispersion polymerizations as a simple method for the preparation of uniform and cross-linked particles with a tunable size, glass transition temperature (T-g) and network structure. Particles with sizes ranging from 1 mm to 3 mm could be obtained by varying monomer concentration and reaction medium, while the T(g)s could be increased from -10 degrees C to 65 degrees C by adjusting the monomer functionality and structure. In order to further demonstrate the potential of these particles, the thioether bonds were simply oxidized to sulfoxides and sulfones to increase the T(g)s and stiffness of the particles significantly. Moreover, the cross-linked particles proved to be reprocessable to a polymer material when a proper catalyst was incorporated. We believe that this simple and efficient method will become a powerful tool for particle preparation, and paves the way for polymer particle reinforcement and recycling.