Shariff, Gani and Sathyanarayana, P. M. and Thimmegowda, M. C. and Ashalatha, M. B. and Ramani, R. and Ranganathaiah, C. (2002) Positron lifetime study of diffusion kinetics in electron irradiated polycarbonate. Polymer Degradation and Stability, 76 (2). 265 - 273. ISSN 1873-2321
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Positron lifetime and gravimetric measurements of iodine sorption and diffusion behaviour in electron-irradiated polycarbonate and un-irradiated polycarbonate are investigated. The increase in ortho-positronium lifetime on electron-irradiation shows that scission of carbonate groups in the main-chain and formation of free radicals is the predominant process. The UV absorption measurement supports this. The free volume in polycarbonate after electron-irradiation seems to be not composed of independent pores but of interconnected channels. The positron results on iodine diffusion in un-irradiated polycarbonate shows a slower diffusion rate, whereas in electron-irradiated polycarbonate faster diffusion is observed. The gravimetric measurement of iodine diffusion attains an early saturation in electron-irradiated polycarbonate as compared to un-irradiated polycarbonate although in both cases the diffusion is nearly Fickian. An exponential type of correlation has been observed between fractional free volume and diffusion coefficient validating Fujita's free volume theory for un-irradiated and electron-irradiated polycarbonate.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Polycarbonate, Electron-irradiation, Ortho-positronium lifetime, Interconnected channels, Diffusion, Fujita's free volume theory |
| Subjects: | D Physical Science > Physics |
| Divisions: | Department of > Physics |
| Depositing User: | Manjula P Library Assistant |
| Date Deposited: | 25 Sep 2019 06:13 |
| Last Modified: | 25 Sep 2019 06:13 |
| URI: | http://eprints.uni-mysore.ac.in/id/eprint/8506 |
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