Structure-property relationship of new polyimide-organically modified silicate-phosphotungstic acid hybrid material system

摘要

A new hybrid material system was successfully developed from the combination of polyimide (PI), organically modified silicate (ORMOSIL), and phosphotungstic acid (HPW) from polycondensation reactions and sol-gel process. The materials were obtained in the form of flexible and free-standing films, with the formation of PI and ORMOSIL network confirmed by Fourier transform infrared. Solid-state phosphorus-31 nuclear magnetic resonance evaluated the HPW structure and confirmed its presence and also structural integrity in the materials after synthesis procedure. Thermogravimetric analysis revealed that the materials were thermally stable up to 773 K, and scanning electron microscopy images and X-ray microfluorescence mapping showed very good compatibility between the organic and inorganic phases with ORMOSIL improving the HPW dispersion. Furthermore, both ORMOSIL and HPW enhanced the permittivity of the materials from 2.5 to 4.3, compared to the neat PI, appointing them as potential candidates for electric and electronic applications.