Morphology, crystalline structure and thermal properties of PEO/MEEP blends

Poly(ethylene oxide) and poly[bis[2-(2′-methoxyethoxy) ethoxy] phosphazene], PEO/MEEP, polymer blends were investigated by thermal analysis, X-ray diffraction, and atomic force microscopy. MEEP is an amorphous polymer and its semicrystalline blends with PEO showed two distinct glass transitions, whose composition dependence was analysed by the Lodge and McLeish self-concentration model. It appears that an amorphous miscible phase is present in these blends. Excess melting enthalpy was observed for blends with high MEEP concentration. PEO lamellar characteristics exhibited changes as a function of MEEP content, both in X-ray patterns and AFM images that indicated the intercalation of MEEP side chains in the lamellar crystalline structure.