SciELO - Scientific Electronic Library Online

vol.22 issue5Biodegradable starch-based films containing saturated fatty acids: thermal, infrared and raman spectroscopic characterizationCharacterization of commercial edible starch flours author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links



Print version ISSN 0104-1428


SILVA, Marcos Anacleto da; TAVARES, Maria I. B.; NASCIMENTO, Suelen A. M.  and  RODRIGUES, Elton J. da R.. Characterization of polyurethane/organophilic montmorilonite nanocomposites by low field NMR. Polímeros [online]. 2012, vol.22, n.5, pp.481-485.  Epub Oct 18, 2012. ISSN 0104-1428.

Polyurethanes are important and versatile materials, mainly due to some of their properties, such as high resistance to abrasion and tearing, excellent absorption of mechanical shocks and good flexibility and elasticity. However, they have some drawbacks as well, such as low thermal stability and barrier properties. To overcome these disadvantages, various studies have been conducted involving organophilic polyurethane/montmorillonite nanocomposites. The investigation of the structure of polyurethane/clay nanocomposites has mainly been done by X-ray diffraction (XRD) and transmission electron microscopy (TEM). In this work, PU/clay nanocomposite films obtained by solution intercalation were studied. The nanocomposites were characterized by XRD and low-field nuclear magnetic resonance (LF-NMR). The LF-NMR measurements, with determination of the spin-lattice relaxation time of the hydrogen nucleus, supplied important information about the molecular dynamics of these nanocomposites. The X-ray diffraction measurements validated the results found by NMR. The thermal stability of the material was also determined by thermogravimetric analysis (TGA) under an inert atmosphere. A slight improvement in this stability was observed in the nanocomposite in comparison with polyurethane.

Keywords : Polyurethane; montmorilonite; nanocomposites; NMR.

        · abstract in Portuguese     · text in Portuguese     · Portuguese ( pdf epdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License