Specific heat and thermal diffusivity of vinylidene fluoride/trifluoroethylene copolymers

✍ Scribed by Y. W. Wong; N. M. Hui; E. L. Ong; H. L. W. Chan; C. L. Choy

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 118 KB
• Volume: 89
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.12551

✦ Synopsis

Abstract

The specific heat (C) and thermal diffusivity (D) of vinylidene fluoride (VDF)/trifluoroethylene copolymers with 70 and 56 mol % of VDF were measured between 200 and 390 K, and the thermal conductivity (K) was calculated from these data. C, D, and K were rather insensitive to the VDF content but varied significantly with the crystallinity. At room temperature, as the crystallinity increased from about 55 to 85%, C decreased by 17%, and D and K increased by 60 and 40%, respectively. For the copolymer with 70 mol % VDF, C exhibited a broad peak, whereas D showed an abrupt drop at the ferroelectric–paraelectric transition near 370 K on heating. The transition temperature on cooling was about 40 K below that observed in the heating run, thus revealing a large thermal hysteresis. For the copolymer with 56 mol % VDF, the transition temperature was much lower, the transition region was narrower, and the thermal hysteresis was barely observable. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3160–3166, 2003