Influence of coupling agents dosage on structure and properties of polyimide hybrid films

The nano Al2O3 powder was uniformly dispersed in poly(amic acid)solution under the ultrasonic,which was treated by different silicon coupling agent dosage,then the Polyimide/nano Al2O3 hybrid films with different dosage of coupling agent were prepared.We studied the fractured morphology,aggregate structure,thermal stability,mechanical property and electric breakdown strength of hybrid films.The result revealed that the amount of coupling agent has little effect on aggregate structure of hybrid films,but the has bigger effect on the dispersion of inorganic nano-particles in PI matrix,the hybrid films shows the highest thermal stability,mechanical property and electric breakdown strength when the content of coupling agent was 4% of that of inorganic particle.