Stabilization capacity of PNIPAM microgels as particulate stabilizer in dispersion polymerization

Abstract In this work, stabilization capacity of PNIPAM microgels as particulate stabilizer in dispersion polymerization is studied. Softness and particle size of PNIPAM microgels as two key parameters are compared. In detail, the recipes for preparation of PNIPAM microgels with controlled softness and particle size are firstly studied. The softness and particle size of PNIPAM microgels are effectively characterized by DLS, SEM and TEM. After obtaining the desired microgels, they are used as particulate stabilizer in dispersion polymerization for preparing polystyrene nanoparticles. The results demonstrate that soft microgels possess better stabilization capacity than hard ones even with smaller particle size. A plausible explanation is proposed in which contact area provided by PNIPAM microgels contributes a lot to the stabilization capacity.