Study of nanocomposites containing core-shell fillers with rigid nano-SiO2 core in PMMA matrix

The synthesis process of core-shall nanoparticles with rigid SiO ₂ core and rubbery polybutyl acrylate (PBA) shell by in situ emulsion polymerization and its application as toughening filler of PMMA matrix, have been reported. The modified nano-SiO₂ powder was dispersed into distilled water with the aid of ultrasound bath. The initiator, ammonium persulphate (APS), was dissolved in a definite amount of distilled water, followed by addition of buffer solution of NaHCO₃ and surfactant. The solution was transferred into the reactor flask and the monomers were fed into the reactor, followed by heating, stirring and cooling. Obtained latex with nano-SiO₂ was mixed with a certain amount of Pure PMMA latex and demulsified. It was observed that the existence of rigid SiO₂ core in the core-shell particles can significantly enhance the modulus of the blends compared to the addition of pure PBA rubber particle alone.