Study On Structure And Properties Of Nano Silicon/Aluminum Oxides Hybrid Polyimide Film

Inorganic-organic nano-composites, which combine the merits of organic and inorganic materials and exhibit excellent mechanical, thermal, optical, electromagnetic and biological properties, have become a hot topic in new-type composites at home and abroad. Nano-composites are one of the most vital and promising materials in the 21st century. Compared with the traditional media, they are greatly improved in the electrical properties, thermal properties, mechanical properties. Inorganic nano-particles hybrid polyimide(PI)shows good corona resistance, such materials (Kapton 100CR film made by the American DuPont company) have been applied in the fields of electronic equipment, electrical engineering, etc.By introducing sol-gel reaction, the polyimide was adulterated with silicon /aluminum oxide nano-particles and a series of different quality percentage of the nano silicon/aluminum oxides hybrid PI films was prepared. The films'dielectric properties, corona-resistant properties, surface morphology and thermal stability were characterized and analyzed by breakdown strength measuring system, corona discharge measuring equipment, SEM and TGA, respectively.SEM shows that a series of nano-particles'size of hybrid PI films is less than 100nm and uniformly disperses in organic phase, where organic phase and inorganic phase form a relative good nano-composite system. The structures and properties of hybrid PI films vary with the percentage of nano silicon/aluminum oxides. With the increase of adulterated silicon oxide, the breakdown strength and thermal decomposition temperature of hybrid PI films increase. When the amount of nano silicon oxide is 15wt %, the hybrid PI films provide with some high qualities, whose breakdown strength is 360kV/mm, 20% more than that of pure PI films, whose thermal decomposition temperature raise 10℃more than that of pure PI films, whose corona-resistant lifespan is longer than that of the pure ones. The corona-resistant lifespan of the hybrid PI films of the amount of 10wt% or 15wt% is as 5 to 6 times as that of pure PI films. According to the experiments and analyses above, we find that a series of the hybrid PI films prepared remain excellent properties of PI, and also show particular property of nano-particles, which is of great importance to modification of PI.