A one-step miniemulsion polymerization route towards the synthesis of nanocrystal reinforced acrylic nanocomposites

The potential of starch nanoparticles (SNPs) to stabilize emulsion droplets during miniemulsion polymerization was investigated. We showed that while starch nanoplatelets were not sufficient to stabilize the monomer droplets by themselves, they did provide a synergistic stabilization effect when used together with a cationic surfactant, reducing the required surfactant amount by a factor of 4. Stabilized monomer emulsion droplets remained stable throughout the polymerization reaction and did not show any sign of Ostwald ripening. Composites obtained by film-casting the dispersions showed a markedly improved mechanical performance when compared to composite films prepared by mixing an SNP suspension with a polymer emulsion followed by film casting. Based on dynamic mechanical analysis, these improvements are the result of enhanced interactions between the polymer and the SNPs.