POLY(TETRAETHYLENE GLYCOL MALONATE) TITANIUM-OXIDE HYBRID MATERIALS BY SOL-GEL METHODS

Hybrid materials have been prepared through the sol-gel route from pol y(tetraethylene glycol malonate) (PTEGM) and titanium isopropoxide (TI P) in acidic media. The bulk gels were characterised by thermal analys is (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 function s of the malonate units. The deformation temperature increases from ca . -50 degrees C to ca. 200 degrees C for 1 greater than or equal to [T IP]/[TEGM] greater than or equal to 0. The gels are optically clear fo r [TIP]/[TEGM] < 1. For 0.5 less than or equal to [TIP]/[TEGM] less th an or equal to 1 TEM shows that particles less than or equal to 5 nm a re present. At higher TIP concentration (> ca. 18 mass%) the gels beco me slightly opaque. WAXS showed that in all the gels (< 200 degrees C) the titania incorporated in crosslinks or in particles was present as non-crystalline material.