ISSN:
0887-6266
Schlagwort(e):
Solubility
;
EVOH
;
glass transition
;
organics
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Sorption isotherms of alcohols in EVOH copolymers were determined by inverse gas chromatography below and above the glass transition temperature. The sorbates studied were: methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, s-butanol, and t-butanol. From the sorption isotherms, Henry's law solubility coefficients (S) were evaluated and correlated to size, condensability, and (SINGLE BOND)OH position in the molecule as well as on temperature. Molecular dimension was an important factor, affecting the solubility via two contrary effects: molecular size and condensability. When comparing alcohols of the same size, primary alcohols were sorbed more than secondary alcohols and these more than tertiary alcohols at every temperature in the study. At low temperatures, the larger the size the greater the solubility, contrary to what was observed at high temperatures. Temperature effect on solubility was also tested applying Van't Hoff's equation. Since S behaved differently below and above Tg for every sorbate two values of the enthalpy of solution were obtained, positive above Tg and negative below Tg. © 1996 John Wiley & Sons, Inc.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
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