Mg(OH)2/polystyrene Hybrid Nanocomposite Particles Prepared by Emulsion Polymerization

Core-shell type Mg(OH) 2 /polystyrene nanocomposite particles were prepared by the emulsion polymerization of styrene in the presence of surface-functionalized Mg(OH) 2 particles. Platelet-like, 80 nm Mg(OH) 2 particles were previously functionalized with 3-(trimethoxysilyl)propyl methacrylate and used for the polymerization to produce stable hybrid composite latexes. Polyencapsulation of the Mg(OH) 2 particles in polystyrene matrix took place when the reaction was conducted with 10 to 30% w/w of Mg(OH) 2 with respect to the monomer. With 40% loading of Mg(OH) 2 , an unstable latex having aggregated particles was produced. Transmission electron microscopic images revealed the hybrid composites to be multi-core/shell type encapsulated particles, while thermogravimetric analysis showed that a difference in the decomposition onset temperature of polystyrene was not apparent in the range of 0 to 40% content of nano-Mg(OH) 2 .