Gas transport properties of high free volume polyarylates based on isophthalic/terephthalic acid chloride mixtures
| Autor: | Susana Hernández-López, F.A. Ruiz-Treviño, U. Scherf, M. Zolutukhin, M.T. Guzmán-Gutierrez |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Terephthalic acid
chemistry.chemical_classification Condensation polymer Chemistry Filtration and Separation Polymer Biochemistry chemistry.chemical_compound Membrane Polymer chemistry Physical chemistry General Materials Science Thermal stability Physical and Theoretical Chemistry Solubility Selectivity Glass transition |
| Zdroj: | Journal of Membrane Science. 305:347-352 |
| ISSN: | 0376-7388 |
| DOI: | 10.1016/j.memsci.2007.08.026 |
| Popis: | This paper reports the synthesis and the gas transport properties measured for polyarylates obtained by high temperature polycondensation of tetramethyl (TMBPA), hexafluoro (HFBPA) and tetramethyl hexafluoro (TMHFBPA) bisphenol A with a mixture of isophthalic (I) and terephthalic (T) acid chlorides (50 mol% initial I/T ratio). The polymers show high glass transition temperature (above 180 °C), good solubility in chlorinated solvents as well as excellent thermal stability (decomposition temperatures above 420 °C). The membranes produced from these I/T polyarylates are transparent and flexible films, and in addition, they have a gas permeability and selectivity balance of properties that falls on, for O 2 /N 2 , and close to, for CO 2 /CH 4 , the experimental “upper bound” limit pointed out by Robeson. The polyarylate membranes based on TMHFBPA I/T lead to the very attractive permeability coefficients of 182, 55, and 16 Barrers for the gases He, CO 2 and O 2 with the corresponding still attractive ideal selectivity factors of 106, 32 and 5.7 for the pair of gases He/CH 4 , CO 2 /CH 4 and O 2 /N 2 . The results reported in this paper are interpreted in terms of the fractional free volume and the most probable inter-segmental distance measured from density determinations and X-rays diffraction patterns. |
| Databáze: | OpenAIRE |
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