High-temperature aging of halar film. I. Study of physicochemical changes

✍ Scribed by Y. P. Khanna; E. A. Turi; J. P. Sibilia; W. Sacks

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 606 KB
• Volume: 29
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1984.070291134

✦ Synopsis

Synopsis

A heat-aging study was undertaken to determine the physicochemical changes in an experimental Halar film [about 80% alternating 1:l copolymer of ethylene (E) and chlorotrifluoroethylene (CTFE)] as a result of exposure to elevated temperatures in air. This work was intended to evaluate how Halar would behave upon exposure to high temperatures as might be the case in wire and cable coating or other similar applications. Samples of Halar film were aged (unstressed) in air at three different temperatures (150,175, and 200°C) for a period of up to loo0 h and then characterized with respect to yellowness index, molecular weight, chemical structure changes, crystalline characteristics, thermal behavior, and tensile prop erties. The results point out no significant deterioration of properties as a result of aging a t 150 or 175°C for 40 days. Actually the exposure at 150 or 175°C increases the molecular weight slightly and enhances crystallinity, which improve the dimensional stability of Halar. Extended exposures at 200°C increased the yellowness index and caused physical distortion of the film. The rest of the properties either remained the same or showed some improvement.