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Gas permeation in miscible blends of poly(methyl methacrylate) with bisphenol chloral polycarbonate
Author(s) -
Chiou J. S.,
Paul D. R.
Publication year - 1987
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1987.070330826
Subject(s) - miscibility , lower critical solution temperature , polycarbonate , materials science , polymer chemistry , differential scanning calorimetry , permeation , polymer , methyl methacrylate , chloral , poly(methyl methacrylate) , analytical chemistry (journal) , thermodynamics , chemistry , organic chemistry , composite material , copolymer , membrane , biochemistry , physics
Abstract The miscibility of poly(methyl methacrylate) (PMMA) with bisphenol chloral polycarbonate (BCPC) has been studied using differential scanning calorimetry (DSC), optical indication of phase separation on heating (i.e., lower critical solution temperature (LCST) behavior), density measurement, and gas permeation. All evidence indicates that PMMA is miscible with BCPC over the whole blend composition range. Single composition‐dependent glass transition temperature and LCST behavior have been observed for each blend. The specific volumes of the blends follow closely the simple additivity rule indicating the interaction between PMMA and BCPC is weak. Gas permeability coefficients for He, H 2 , O 2 , Ar, N 2 , CH 4 , and CO 2 measured at 35°C under 1 to 2 atm upstream pressure are lower than those calculated from the semilogarithmic additivity rule. The difference between this calculated permeability and the measured one increases with gas molecular size. As a result, the ideal gas separation factors for He/CH 4 , CO 2 /CH 4 , and O 2 /N 2 gas pairs estimated from the ratio of pure gas permeabilities are higher than predicted from the semilogarithmic additivity rule. These permeation results were interpreted in terms of the free volume theory and the activated state theory, which have been proposed to describe gas transport behavior in polymer mixtures.