Poly(tetraethylene glycol malonate)–titanium oxide hybrid materials by sol–gel methods

Abstract

Hybrid materials have been prepared through the sol–gel route from poly(tetraethylene glycol malonate) (PTEGM) and titanium isopropoxide (TIP) in acidic media. The bulk gels were characterised by thermal analysis (TG, DSC and TMA), wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM) and FTIR. The results indicate that the gel incorporates –Ti–O–Ti– crosslinks appended to the dicarbonyl functions of the malonate units. The deformation temperature increases fromca.–50 °C to ca. 200 °C for 1≥[TIP]/[TEGM]≥0. The gels are optically clear for [TIP]/[TEGM]<1. For 0.5≤[TIP]/[TEGM]≤1 TEM shows that particles ≤5 nm are present. At higher TIP concentration (>ca. 18 mass%) the gels become slightly opaque. WAXS showed that in all the gels (<200 °C) the titania incorporated in crosslinks or in particles was present as non-crystalline material.