Vol.:(0123456789) 1 3 Applied Nanoscience (2019) 9:987–996 https://doi.org/10.1007/s13204-019-01035-z ORIGINAL ARTICLE Structural characterization, thermal and mechanical properties of polyurethane–MgAl–layered double hydroxide nanocomposites prepared via physical dispersion G. Starukh 1  · V. Budzinska 2  · S. Ya. Brychka 1 Received: 3 January 2018 / Accepted: 9 April 2019 / Published online: 29 April 2019 © King Abdulaziz City for Science and Technology 2019 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 charac- terized 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 signifcant 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 efect of partially exfoliated DS–LDH layers in PU matrix. DTA and DSC analysis confrmed 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. Keywords Polyurethanes · Nanofllers · Layered double hydroxides · Organic–inorganic nanocomposites Introduction Polyurethanes (PU) are extraordinarily versatile polymeric materials which can be tailored to meet the highly diversifed demands of modern technologies such as coatings, adhe- sives, foams, and thermoplastic elastomers. There is a big variety of PU nanocomposites. PU has many applications in infrastructural industries. Very wide applicability of PU results from the fact that their properties can be modifed by choosing appropriate raw materials, catalysts, by employing various production methods and by employing various meth- ods for further processing. The application of PU for the protective construction for civil engineering is well known. PU good adhesion, the enhanced physical resistance of the structural surface, the improved chemical resistance, and increased electrical resistivity enable PU adhesives to be used extensively in such applications, as sandwich compos- ites, constructions, tools, repair of vehicles, sheet molding compound (Somarathna et al. 2018). As an adhesive, PU can efectively wet the surface of many substrates. Its low viscos- ity allows it to be spread through porous substrates. Moreo- ver, PU flms and coatings also exhibit good toughness and resistance to water and a broad range of chemicals. However, the application of PU is restricted by its low tensile strength and thermal stability. The clays were started to be widely involved in polymer preparation since Toyota researchers frst had demonstrated the improvement of the organic–inor- ganic assembly mechanical properties in comparison with pristine nylon 6 (Okada et al. 1988). The majority of the investigations of clays application as nanofllers for poly- mers have been focused on montmorillonite-type layered silicate (Fukushima & Inagaki 1987; Usuki et al. 1993; Ler- oux 2006). As montmorillonite has a relatively low charge density and thus its exfoliation is difcult to achieve, there is a need in the search for inorganic additives to avoid this drawback. In this content, extensive studies were devoted to polymeric organic–inorganic assemblies using alumina (Gorninski et al. 2015), carbon nanotubes (Yamamoto and * G. Starukh starukh_galina@ukr.net 1 Chuiko Institute of Surface Chemistry, NAS of Ukraine, 17 General Naumov Str., Kyiv 03164, Ukraine 2 Institute of Macromolecular Chemistry, NAS of Ukraine, Kharkiv Highway, 48, Kyiv 02160, Ukraine