The influence of clay-like sepiolite on the structure and properties of polyurethaneurea/sepiolite nanocomposites

A series of polyurethaneurea (PUU) nanocomposites based on clay-like sepiolite (Sp) with the modification of gamma-aminopropyltriethoxysilane (KH550) were prepared via in situ polymerization from poly(propylene glycol), tolylene-2,4-diisocyanate (TDI) and 3,3'-dichloro-4,4'-diamino-diphenylmethane(MOCA). Morphology and structure of nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results indicated that KH550-Sp was dispersed homogeneously in the PUU matrix, which facilitated the formation of chemical bonds between KH550-Sp and the hard segment of PUU. The thermostability and mechanical properties were studied by the thermogravimetric (TG) analysis and tensile tests. The results showed that the onset decomposition temperature and tensile strength of nanocomposites was higher than those of pure PUU.