Effect of MMT content on structure of polyimide/(TiO2+MMT) nanocomposite films

The polymer/inorganic nanometer composite dielectric film with good mechanical, electrics and thermal properties, has become a highlight in the field of materials research. MMT and TiO₂ are doped into the polyimide to study the influence of the mass ratio of MMT and TiO₂ on the structure of polyimide matrix nanocomposite materials. In this paper different components of MMT are doped into the PI/(TiO₂+MMT) nanocomposite film through the in situ polymerization. The film thickness is 30 micrometer. To take the quality of TiO₂ for reference, the mass ratio between TiO₂ and MMT were changed which doped into the nanocomposite film, dividing into two different series named series A (the mass fraction of TiO₂ is 1%) and series B (the mass fraction of TiO₂ is 3%). The structures of two series films are tested by infrared spectrum (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) to study the influence of the mass fraction of MMT on the structure of the PI/(TiO₂+MMT) nanocomposite film. The results show that the addition of inorganic nanoparticles doesn´t affect the accomplishment of polyimide matrix imidization which reflects completely. The distribution of TiO₂ and MMT particles in the polyimide matrix are uniform, most of MMT sheets paralleled to the film surface and this kind structure can prevent electric field damage materials and increase corona life of nanocomposite films obviously. The appropriate proportions of TiO₂ and MMT inorganic particles in composite films can raise the film performance. The comprehensive performances of B1 sample are best.