Hybrid materials based on the reaction of polyorganophosphazenes and SiO2 precursors

New molecular composite materials can be prepared based on an inorganic oxide network and an organic polymer. The polymeric component generally requires low process temperatures, due to the presence of the organic backbone or side groups. A sol-gel process therefore is suitable for synthesizing the inorganic component by dissolving soluble polymers into sol-gel precursor solutions in order to obtain ceramic and polymeric solid phases. In this work polyorganophosphazenes were used because they have many technologically interesting properties (chemical, optical, electrical, mechanical). The methods to obtain covalent bonds between polymer and inorganic network and to obtain homogeneous, transparent hybrid materials without phase separation were studied. It was possible to avoid phase separation by preparing phosphazenes containing free hydroxyl functions and by adequately choosing the experimental conditions.