Nylon 6/calcium carbonate nanocomposites: Characterization and properties

Two polymorphic modifications of calcium carbonate nanoparticles (calcite and aragonite) characterized by different shape and coated with fatty acids were used as reinforcement phases of Nylon 6. Nylon 6 based nanocomposites filled with 1% and 5% by weight of calcite and aragonite were prepared by melt mixing. Morphological analysis performed on the fractured surface of nanocomposites showed that the coating agent permits to obtain uniform and fine nanoparticles dispersion. DMTA analysis revealed that nanoparticles increase the glass transition temperature of Nylon 6 Up to 12 degrees C in the case of calcite, while a less pronounced increase was recorded for aragonite. Finally, structural analyses (FT-IR and WAXS) underlined that calcite nanoparticles promote and stabilize the gamma-crystalline form of Nylon 6, while in the case of aragonite nanofillers the alpha-crystalline form was still dominant.