Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

✍ Scribed by Takeshi Shigetomi; Hiroyuki Tsuzumi; Keio Toi; Tomoyasu Ito

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 199 KB
• Volume: 76
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000404)76:1<67::aid-app9>3.0.co;2-5

✦ Synopsis

The sorption and diffusion of water vapor in poly(ethylene terephthalate) (PET) film were measured by applying a thermogravimetric analyzer (TG-DTA), which customarily has been used to detect the weight loss of a sample with the increase of temperature under a given atmosphere. In this case, we detected the weight gain of PET film by sorption of water vapor under a given humidity at a constant temperature. Sorption-rate curves were successfully obtained in spite of the low solubility of PET film and the presence of Fickian-type curves. The solubility was better described according to the dual-mode sorption model. The diffusion coefficients were determined in their initial slopes by the short-time method. We found that the diffusion coefficient depended on vapor pressure.