Free volume study of poly(chlorotrifluoroethylene) using positron annihilation spectroscopy as a microanalytical tool

Ramachandra, P. and Ramani, R. and Ravichandran, T. S. G. and Ramgopal, G. and Gopal, S. and Ranganathaiah, C. and Murthy, N. S. (1996) Free volume study of poly(chlorotrifluoroethylene) using positron annihilation spectroscopy as a microanalytical tool. POLYMER, 37 (15). pp. 3233-3239. ISSN 0032-3861

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Official URL: http://dx.doi.org/10.1016/0032-3861(96)88467-9

Abstract

Positron lifetimes and X-ray diffraction measurements were carried out on poly(chlorotrifluoroethylene) films annealed between 25 and 215 degrees C. The positron lifetime results were used to determine the free volume and XRD data were used to determine the apparent crystallite size and crystallinity. The glass transition temperature (T-g) of 52 degrees C obtained from positron results is in agreement with that obtained by thermal analysis. The average free volume cell size is 74 Angstrom(3) in films annealed below T-g, and increases to 84 Angstrom(3) in samples annealed above T-g. Although the observed changes in positron lifetime parameters as a function of annealing temperature are small, they are significant for the kind of material investigated. Our observations are explained in terms of thermally activated chain mobility, local relaxations and long-range motions. We further estimate, for the first time, the activation energies in the amorphous and crystalline regions of the polymer using the Goldanskii kinetic relations. Copyright (C) 1996 Elsevier Science Ltd.

Item Type: Article
Additional Information: Unmapped bibliographic data: DA - 1996/07// [EPrints field already has value set] LA - English [Field not mapped to EPrints]
Uncontrolled Keywords: free volume, lass transition temperature, positron lifetime
Subjects: Physical Sciences > Physics
Divisions: PG Campuses > Manasagangotri, Mysore > Physics
Depositing User: Users 22 not found.
Date Deposited: 07 May 2013 09:49
Last Modified: 03 Sep 2013 05:49
URI: http://eprints.uni-mysore.ac.in/id/eprint/7162

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