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چکیده
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Polyurethane elastomers (PUEs) are a category of highly significant engineering polymers with excellent properties and a broad range of commercial applications in many areas, such as coatings, adhesives, construction, automatic industries, medical devices, and sealants.1,2 Incorporating Fe3O4 magnetic nanoparticles into organic polymers to fabricate organic-inorganic nanocomposites is highly of interest owing to the versatile properties of this class of nanocomposites.3 In this study, a series of polyurethane elastomer nanocomposites were prepared via incorporation of thiacalix[4]arens (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) into polyurethane matrices using in situ polymerization method. The synthesized TC4As-Fe3O4 nanoparticles were synthesized and characterized by FTIR, XRD, TGA, VSM and SEM. It is expected that the TC4As on the surface of nanoparticles can improve the dispersion of the Fe3O4 nanoparticles within polyurethane matrices due to increase in interphase interaction arising from formation of covalent bonding. The effects of the functionalization of nanoparticles with TC4As on the various properties of the prepared polyurethane nanocomposites were investigated and compared with both polyurethane nanocomposites incorporated with unmodified nanoparticles and pure polyurethane elastomer using ATR-FTIR spectroscopy, TGA, dynamic DMTA, XRD, SEM and a universal tensile tester. The enhanced and fine dispersion of the TC4As-Fe3O4 nanoparticles in the nanocomposites were demonstrated by means of SEM analysis. It was also found that the functionalization of nanoparticles with TC4As bestows better mechanical and thermal properties to polyurethane nanocomposites compared to unmodified nanoparticles. TGA results showed that TC-MPUE and TS-MPE samples comprising from TC4As functionalized Fe3O4 nanoparticles have higher Tonset, than PUE and MPUE samples and are more thermally stable than the other samples. In addition, tan δ curves also showed that glas
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