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 μm to 3 μm could be obtained by varying monomer concentration and reaction medium, while the T_gs could be increased from -10 °C to 65 °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_gs 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.