Moisture diffusion properties of HFPE-II-52 polyimide

Moisture diffusion properties of the polyimide HFPE-II-52 were determined using weight gain, weight loss, and swelling experiments over a temperature range of 25-200 degrees C. Below 100 degrees C, diffusivity was measured using standard weight loss and weight gain methods. Above 100 degrees C, diffusivity is found by weight loss experiments performed by placing moisture saturated samples in an oven and recording weight loss dynamically. The diffusivity of the polyimide was found to obey the Arrhenius relation over the entire range of temperature. Weight gain experiments were performed to determine the equilibrium level of moisture absorbed by the polyimide as a function of relative humidity. Swelling experiments were performed to measure swelling strain as a function of moisture absorption. (c) 2006 Wiley Periodicals, Inc.