One-step thiol-isocyanate dispersion polymerization: Preparation of uniform, cross-linked and functional particles

Uniform and highly cross-linked particles with functional groups are very useful but difficult to be achieved in traditional dispersion polymerization. Herein, we develop a one-step dispersion polymerization based on thiol-isocyanate reaction to prepare such particles. This polymerization proceeds energy-efficiently at ambient temperature without additional catalyst/initiator or UV treatment, achieves high monomer conversion and has little side reaction. It is demonstrated that particles with size ranging from 1.8 to 8 μm can be fabricated via adjusting the concentration of stabilizer and ratio of monomer/ethanol. The generated thiourethane linkages endow particles with high glass transition temperature (Tg) and uniform networks. In addition, the particles can be intrinsically functionalized and available for further modification due to thiol-isocyanate step-growth mechanism. As an attempt to perform thiol-isocyanate reaction in dispersion polymerization, this method offers feasibility for preparing uniform, functional and highly cross-linked particles in one-step dispersion polymerization.