Synthesis and Properties of Polyimide Silica Nanocomposite Film with High Transparent and Radiation Resistance

In order to prepare flexible glass cover sheet materials suitable for space solar cells, fluorinated diamine 2,2’-bistrifluoromethyl benzidine (TFDB) and fluorinated dianhydride 4,4’ (hexafluoroisopropyl) diphthalic dianhydride (6FDA) as the monomer, polyimide (PI)/SiO(2) composite film was synthesized by in situ polymerization, and the influence of coupling agent and SiO(2) nanoparticle content on the film structure and properties was studied. The results show that PI synthesized from fluorine-containing monomers has better light transmittance, and the highest transmittance can reach 91.4%. The average visible light transmittance of the composite film decreases with the increase of SiO(2) content, and the transmittance of the film decreases less in the high-wavelength region and greatly decreases in the low-wavelength region. The tensile strength and elastic modulus of PI/SiO(2) composite film increase with the increase of SiO(2) content, first increase and then decrease, reaching the maximum when the content is 10%; while the elongation at break of the composite film gradually increases with the increase of SiO(2) content reduce. The thermal stability of PI/SiO(2) composite film increases with the increase of SiO(2) content. The doping of nano-SiO(2) significantly suppresses the influence of irradiation on the mechanical properties of the film.