Spectrophotometric determination of water vapor permeation through polymer films
โ Scribed by R. V. Holland; R. A. Santangelo
- Publisher
- John Wiley and Sons
- Year
- 1982
- Tongue
- English
- Weight
- 554 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0021-8995
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โฆ Synopsis
A novel method for measuring the permeation of water vapor through polymer films is described. A cellulose detector film incorporating cobalt chloride in a blue anhydrous form is sealed between two pieces of test film in a specially designed cell. The cell is placed in a controlled temperature and humidity cabinet, and the disappearance of the blue color of the cobalt chloride is recorded spectrophotometrically as water vapor diffuses through the test film into the detector film. This simple method of determining water-vapor-transmission rates is more rapid than standard gravimetric procedures because of the highly sensitive detection technique.
๐ SIMILAR VOLUMES
The accurate measurement of water vapor sorption and permeation in polymers is complicated because water has a tendency to adsorb on high energy surfaces, a relatively high heat of vaporization, and a high solubility in most polymers. These issues and the difficulties they cause in the design of sor
The permeation of water has been measured through polyimide film over a range of thicknesses, temperatures, and relative humidities. The concentration of absorbed water was found to depend on the relative humidity and not on the temperature or sample thickness, reaching a maximum of one water molecu