Structural characterization, thermal and mechanical properties of polyurethane–MgAl–layered double hydroxide nanocomposites prepared via physical dispersion

Abstract

Polymer–clay nanocomposites were prepared via physical dispersion of dodecyl sulfate (DS)-intercalated MgAl–layered double hydroxides (MgAl–LDHs) in polyurethane (PU). The structure, mechanical behavior, thermal stability as well as ultraviolet transmittance of the PU–LDH hybrids were studied systematically. The obtained hybrid materials were characterized with XRD, FTIR, TGA, DSC, UV–Vis spectroscopy, SEM and mechanical testing. The optimal content of MgAl/DS–LDHs in PU was determined. The testing of mechanical properties of PU–MgAl/DS–LDHs nanocomposites showed significant improvements in tensile strength and elongation at break, especially for the DS/LDHs content of 5 wt%. The observed improvement in mechanical properties is attributed to the relatively better reinforcing effect of partially exfoliated DS–LDH layers in PU matrix. DTA and DSC analysis confirmed the increased thermal stability of PU–MgAl/DS–LDH materials. The obtained results suggested potential application of physical dispersion of inorganic additives in the polymer matrix as a promising method for obtaining of PU nanocomposites.