Abstract: A new type of polyimide material was prepared via a blending method utilizing BPDA/ODA and PMDA/ODA polyamide acid as precursors. The relationship of the mechanical, thermal and electric properties of the derived material and the blending ratio was also investigated. Universal material testing machine, dynamic mechanical analysis and precision impedance analyzer were employed during the optimization of the blending ratio which associated closely with the physicochemical properties mentioned above. The characterization indicated that the elongation at break of the blended polyimide could be significantly improved by simply using a suitable blending ratio, meanwhile without compromising its good heatresistant property. The temperature at the turning point for dielectric loss rapid rise was above 250 ℃. This kind of material was very promising in wide application of manufacturing the enameled wire leveled above 240.

Key words: film, heat resistance, enameled wire, electric property, polyimide