Thermal Expansion of Irradiated Polytetrafluoroethylene

Subrahmanyam, HN and Subramanyam, SV (1987) Thermal Expansion of Irradiated Polytetrafluoroethylene. In: Journal of Polymer Science Part B: Polymer Physics, 25 (7). pp. 1549-1556.

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Abstract

The thermal expansion coefficient of gamma-irradiated Polytetrafluoroethylene (PTFE) has been measured in the temperature range 80-340 K by using a three-terminal capacitance technique. The samples are irradiated in air at room temperature with gamma rays from a $Co^{60}$ source at a dose rate of 0.26 Mrad/h. The change in crystallinity is measured by an x-ray technique. The expansion coefficient is found to increase with radiation dose below 140 K owing to the predominant effect of degradation. Above 140 K, the expansion coefficient is found to decrease with radiation dose because of the enhanced crystallinity. The temperatures of the two first-order phase transitions are also found to shift to lower temperatures owing to degradation of PTFE.

Item Type:	Journal Article
Publication:	Journal of Polymer Science Part B: Polymer Physics
Publisher:	John Wiley & Sons, Inc.
Additional Information:	The copyright belongs to John Wiley & Sons, Inc.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 Dec 2005
Last Modified:	19 Sep 2010 04:22
URI:	http://eprints.iisc.ac.in/id/eprint/4409

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