| 초록 |
Among the high-performance polymeric materials, polyimides(PIs) represent an optimal combination for many high-tech applications that require great mechanical strength, a resistance to high temperatures and low dielectric constant. To some degree, unfortunately, these polyimides interact with the environment, absorbing moisture that can alter their dielectric properties. The nature of water absorbed into polymers has been studied in detail using Nuclear Magnetic Resonance(N.M.R.) and Differential Scanning Calorimetry(D.S.C). In this paper, however, the dielectric behavior of water absorbed into PIs was investigated in detail using Film Dielectric Property Analyzer(FDPA). In our laboratory, widely applied Polyimides with different precursor type were prepared. Then, the dielectric constant(((), dissipation factor(tan(), and dielectric loss factor(((() of these PIs were measured at a frequency(1kHz) as a function of time. Finally, the relationship between the dielectric constant and water diffusivity was investigated via the capacitance method
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