Preparation And Characterization Of Polyimide Nano-Hybrid Films

With the development of science and technology, the more rigid claims to the properties of materials are put forward. Organic/inorganic hybrid materials have obtained more and more attentions because of their present characteristics and properties of both moieties. Polyimide (PI), as a typical kind of engineering polymer material with highest thermal stability hitherto, has been widely used in the aeronautic and electronic industries because of its outstanding performances such as excellent thermal and electric properties and mechanical properties. Its high thermal stability and glass transmission temperature are beneficial to the distribution of the nano-particles, accordingly avoiding precipitation among them in the synthesis process of the polyimide. To obtain this composite, it is feasible to adopt the sol-gel approach by which the inorganic skeleton can from and shape under mild condition. In this paper, a kind of hybrid PI film was prepared by incorporating SiO2 and Al2O3 particles into the polyamic acid matrix resin through sol-gel reaction. Polyimide composite film with a varied amount of SiO2 and Al2O3 was prepared. The two (original and dopped) PI films'surface morphology and structure were characterized and measured by IR, AFM, TGA and dielectric spectroscope. It turned out that certain of homogeneous hybrid system had formed. With the instruction of the inorganic nano-particles, the thermal stability of the hybrid PI/SiO2-Al2O3 film had improved. It also proved that with the increase of the inorganic moiety, the precipitation of the particles occurred and, therefore, the dielectric constant of the film increased. In order to obtain materials with excellent properties, it is of most importance to improve the miscibility of the two phases. By now the researches on the hybrid PI film are at the beginning stage, and there exist several problems such as the control of distribution and size of particles, and the affection of the inorganic moiety to the electric property. The further researches will go on.