Preparation and characterization of polyurethane-organoclay nanocomposites

Nanocomposite polyurethane (PU)-organoclay materials have been synthesized via in-situ polymerization. The organoclay is first prepared by intercalation of tyramine into montmorillonite (MMT)-clay through ion exchange process. The syntheses of polyurethane-organoclay hybrid films containing different ratios of clay were carried out by swelling the organoclay into diol and diamine followed by addition of diisocyanate and then cured. The nanocomposites with dispersed and exfoliated structure of MMT were obtained as evidenced by X-ray diffraction and scanning electron microscope. X-ray diffraction showed that there is no peak corresponding to d(001) spacing in organoclay with the ratios up to 20 wt%. SEM images confirmed the dispersion of nanometer silicate layers in the polyurethane matrix. Also, it was found that the presence of organoclay leads to improvement in the mechanical properties. The tensile strength was increased with increasing the organoclay contents to 20 wt% by 221 % in comparision to the PU with 0% organoclay.