Mechanical and thermal properties of polypropylene and layered double hydroxides nanocomposites

The recent interest in polymer nanocomposites involving layered double hydroxides (LDH) is due to improved thermal stability, flame resistance, mechanical and barrier properties. The LDHs are structurally described as the stacking of layers with positively charged hydrated anions intercalated between these lamellae. In this paper, polypropylene nanocomposites with Mg / Al-HDL unmodified and modified with sodium dodecyl sulfate (DS) were prepared in the internal mixing chamber equipped with roller rotors and heated to 190 deg C. The nanocomposites were injected molded and then morphology, mechanical and thermal properties were evaluated by X-ray diffraction, tensile tests and DSC, respectively. The results revealed that both LDH and LDH-DS reached a good degree of dispersion in the PP matrix, resulting in increased stiffness, but reduced capacity for deformation and toughness of nanocomposites. The crystallinity of the nanocomposites was higher compared to the PP matrix. (author)