Non-hydrolytic sol–gel synthesis of polypropylene/TiO2 composites by reactive extrusion

An original way to synthesise polypropylene/titanium dioxide (PP/TiO2) composites combining non-hydrolytic sol–gel chemistry and reactive extrusion was reported. The reaction between titanium alkoxide as a precursor an acid anhydride oxygen donor at 240 °C first evaluated optimised in alkane liquid medium. TiO2 present essentially crystalline anatase form when synthesised squalane with domain size around 10 nm. Based on these encouraging results, the synthesis adapted that means high temperature molten viscous polypropylene for short times (few minutes maximum). proof of concept evidenced through formation amorphous TiO2-based inorganic domains 1 µm within polymer matrix from isopropoxide acetic anhydride. A condensation degree 79% obtained. To optimise polymer/filler interface, precursors donors different alkyl chain lengths were evaluated. Hexanoic substituent tetrakis 2-ethylhexyloxide used. contribution appeared be dominant particle dispersion state. (PP)/TiO2 composite hexanoic showed narrowest diameter distribution mean 700