Preparation and physical properties of poly (propylene glycol)/titania hybrid materials

Some transparent hybrid materials were prepared with poly(propylene glycol) (PPG)(M-n=1000, 2000, 3000) and titanium tetraisopropoxide (TiOPr) by the sol-gel process. The hybrid films exhibited high transparency in a visible light region and the film containing 10 wt% TiOPr cut UV-rays below 320 nm. The refractive index linearly increased and the Abbe number decreased with increasing volume fraction of titania. The refractive index increased with increasing M-n of PPG when the titania content is constant. The tensile strength of the hybrids is improved and the strain is decreased with increasing TiOPr content. The dynamic viscoclastic properties and small-angle X-ray scattering suggested that the inorganic domains consisting of titania and silica were formed and that the size of the domains became larger and the PPG segments were more restricted and the storage modulus at the rubbery-plateau region increased with increasing TiOPr. The increase in M-n of PPG increases the amount of titania per ethoxysilyl end groups of PPG when the TiOPr content is constant and the domain size thus becomes larger.