Paper Title
Electric Resistivity for Heat Resistant Polymer Films at High Temperatures

Abstract
The development of bio based polymers is indispensable for the establishment of a sustainable low-carbon society. A number of aliphatic bio based polymers have been developed, however, their low glass transition temperature, Tg, and only a small percentage of their substitutes limited their use for various applications. We have developed so far bio based PIs from bio available aromatic diamines, which were photodimers of 4-aminocinnamic acid (4ACA) derived from genetically manipulated Escherichia coli [1-4]. These bio based PI films showed ultrahigh thermal resistance with the temperature at 10% of mass loss, T10, values over 425 °C and no Tg values under 350 °C, which is the highest value of all bio based plastics reported thus far. This advanced thermal property can be useful for electric devices such as flexible polymeric electrodes that can be annealed at high temperature. On the application for electric devices, the electric properties are very important, however, the electric properties are not fully understood for these films at high temperatures. In this study, the temperature dependence of the volume resistivity for heat resistant polymers, e.g. Kapton, was measured at a temperature range of 20 ºC - 400 ºC in air. The volume resistivity was measured by a super-resistant meter with an applied voltage of 100 V. The volume resistivity at 200 ºC was 3×1013Ωcm, which coincides with the published values of the production company. The volume resistivity showed an Arrhenius-type dependency and the activation energy was determined to be 78.3kJ/mol independently of the film thickness. The accurate measurement for the resistance at high temperatures is discussed.