Design and Optimization of a Permeation Testing System for Polymer Coatings
Adrian E. Verwolf
Measurements of liquid permeation through freestanding Parylene C membranes were made using a high- performance testing system, which demonstrated fast response (≤ 30 seconds) to changing concentrations in the sweep gas stream and detectability of less than 20 mPa of water vapor. The bulk of the maximum measured transport rates through Parylene C were attained within 30 minutes of injecting water into the feed side of the dry test cell. The characteristic time-transport rate curves were similar to those produced via water vapor fed directly into the sweep-gas stream from a novel in situ water vapor diffusion reference membrane. Average values of diffusivity D measured at 37 °C ranged from 8.1e-9 to 8.8e-9 cm2/s. The implications of experimental results are discussed with respect to transient permeation for medical device coating applications specifically and metrology generally.
Materials and Processes for Medical Devices 2011
August 8-10, 2011
permeation, Parylene C, medical devices, polymer coatings