The electrical, mechanical and thermal properties of Mg(OH)2/ZnO/PI nanocomposite films

Nano Mg(OH) 2 /Zn(OH) 2 particles were prepared using a reverse precipitation method, and nano Mg(OH) 2 /ZnO/PI composite films with different mass contents of Mg(OH) 2 /ZnO were successfully prepared using in-situ polymerization and thermal imidization. The surface morphology, thermal stability and dielectric properties of the films were characterized and discussed. Several results were obtained: the nanoparticles were homogeneously dispersed in the matrix; the thermal stability was decreased; the relative permittivity and dielectric loss were increased; and the Young’s modulus of PI-4% was 2226 MPa, having increased by 99% compared to the neat PI. This paper introduces the formalism of the electric modulus in order to research the dielectric relaxation behavior of the composites studied, and the result from the Cole–Davidson semicircle show that the increase of nano Mg(OH) 2 /ZnO concentration led to an increase in the inhomogeneous distribution of the relaxation time. According to the theory of space charge limited current, the aging threshold was increased, the breakdown was increased to 296.6 kV/mm, the pure film was 271.1 kV/mm, and the electric property of polyimide was improved.