Water-binding and oxygen permeability in poly(vinyl alcohol) films

Title
Water-binding and oxygen permeability in poly(vinyl alcohol) films
Publication Date
2002
Author(s)
Lien, Lily
Fellows, Christopher
( author )
OrcID: https://orcid.org/0000-0002-8976-8651
Email: cfellows@une.edu.au
UNE Id une-id:cfellows
Copeland, Lachlan
Hawkett, Brian S
Gilbert, Robert G
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/CH02007
UNE publication id
une:6029
Abstract
The measurement and interpretation of isotherms for sorption of water onto, and oxygen permeability of, polymer substrates are important for designing polymers in applications such as agricultural seed coatings. In a preliminary study of water sorption in the commonly used copolymer poly(vinyl alcohol-'co'-vinyl acetate), moisture sorption isotherms were measured for a series of substrates of different comonomer composition at 25°C. The data were fitted to the D'Arcy-Watt model, which gave physically reasonable values for parameters related to the strength of monolayer adsorption to high affinity sites on the substrate and the number of sites for secondary water adsorption per unit mass. The oxygen permeability of poly(vinyl alcohol) films was found to be a function only of the water content of the films, with no other obvious contributing factors. Marked differences were seen in the populations of 'bound' and 'unbound' water characterized by ¹H nuclear magnetic resonance (NMR) spectroscopy and moisture sorption isotherm fitting. There was no correlation of oxygen permeability with 'bound' or 'unbound' water measured by any means, a fact suggesting that there is a continuum of water environments within the materials.
Link
Citation
Australian Journal of Chemistry, 55(8), p. 507-512
ISSN
1445-0038
0004-9425
Start page
507
End page
512

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