Advanced Calcium Copper Titanate/Polyimide Functional Hybrid Films with High Dielectric Permittivity

摘要

High-technology fields require new high-dielectric-permittivity materials. Functional hybrid films with high dielectric permittivity and good thermal stability are realized by employing giant dielectric permittivity calcium copper titanate (CCTO) as a functional inorganic filler and thermosetting polyimide (PI) as a polymer matrix. The in situ polymerization process drives the CCTO fillers into the PI homogeneously, and therefore the CCTO/PI hybrid films show good dielectric properties. Both the giant dielectric permittivity that originates from the internal boundary layer capacitance and the semiconducting characteristic of the CCTO fillers induce the resultant high dielectric permittivity of the CCTO/PI hybrid films. The dielectric permittivity is as high as 49 when the concentration of CCTO filler reaches 40 vol% at 10~2 Hz, which is 14 times larger than that of a pure PI matrix, while the film is still flexible and has good thermal stability. It is believed that the functional CCTO/PI hybrid films with high dielectric permittivity could be applied in future high-technology fields.