ANALYSIS OF MELT INTERCALATED POLY(ETHYLENE OXIDE)/MONTMORILLONITE NANOCOMPOSITES

This investigation is focused on the preparation and characterization of poly(ethylene oxide)/sodium montmorillonite (PEO/NaMMT) nanocomposites. PEO/NaMMT samples were prepared by melt intercalation and analysed by small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and non-isothermal thermogravimetry (TGA). SAXS measurements show that PEO can be intercalated into the gallery region of NaMMT. DSC analysis reveals that the crystallinity of PEO decreases as the amount of NaMMT increases, but it is observable even at very high NaMMT loadings. The melting temperature of PEO decreases only with addition of NaMMT higher than 50 wt. % while its glass transition temperature practically does not change in nanocomposites. FT-IR analysis indicates that in nanocomposites the helical structure of PEO chains is distorted and consequently its crystallinity is changed, what is in accordance with the DSC results. The thermal degradation of both pure PEO and PEO/NaMMT nanocomposites occurs through one degradation step. PEO shows an increased thermal stability in all PEO/NaMMT nanocomposites compared to pure PEO where the increase is more pronounced for lower NaMMT loadings.