Sorption and diffusion of normal alkanes through poly(ethylene‐co‐vinyl acetate) membranes |
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Authors: | S Anil Kumar M G Kumaran Sabu Thomas |
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Institution: | 1. Department of Chemistry, N. S. S. College, Ottapalam, Palakkad, Kerala, India;2. Rubber Research Institute of India, Kottayam, Kerala 686009, India;3. School of Chemical Sciences, Mahatma Gandhi University, Priyadarshini Hills Po, Kottayam, Kerala 686560, IndiaSchool of Chemical Sciences, Mahatma Gandhi University, Priyadarshini Hills Po, Kottayam, Kerala 686560, India |
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Abstract: | The transport behavior of uncrosslinked and crosslinked poly(ethylene‐co‐vinyl acetate) membranes has been investigated using normal alkanes as probe molecules, in the temperature range of 30–60 °C. Benzoyl peroxide was used for crosslinking the matrix. It has been observed that, a critical concentration of crosslinker is necessary for maximum solvent uptake, followed by a decrease at higher concentration. The effect of free volume on liquid transport was investigated by positron annihilation lifetime spectroscopy. The mechanism of transport has been found to deviate from the regular Fickian behavior. The dependence of the transport coefficients on crosslink density, nature of penetrants, and temperature was studied. The polymer–solvent interaction parameter, enthalpy, and entropy of sorption have also been estimated from the transport data. The affine and phantom models for chemical crosslinks were used to predict the nature of crosslinks. Finally, the experimental sorption data were compared with theoretical predictions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2470–2480, 2007 |
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Keywords: | benzoyl peroxide crosslinking diffusion membranes poly(ethylene‐co‐vinyl acetate) sorption and diffusion X‐ray |
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