Premium
Gas permeation in miscible homopolymer‐copolymer blends: II. Tetramethyl bisphenol‐A polycarbonate and a styrene/acrylonitrile copolymer
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.1987.070340414
Subject(s) - copolymer , acrylonitrile , materials science , polycarbonate , polymer blend , polymer chemistry , sorption , miscibility , hildebrand solubility parameter , thermodynamics , solubility , flory–huggins solution theory , styrene , polystyrene , gaseous diffusion , polymer , chemistry , composite material , physics , adsorption , electrode
Gas sorption and transport properties for He, H 2 , O 2 , N 2 , Ar, CH 4 , and CO 2 at 35°C near atmospheric pressure have been obtained for miscible blends of tetramethyl bisphenol‐A polycarbonate (TMPC) and a random copolymer of styrene with acrylonitrile (SAN) containing 9.5% by weight of acrylonitrile. All gas permeability, diffusion, and solubility coefficients obtained are lower than that calculated from the semilogarithmic additivity rule. These results are qualitatively interpreted by ternary solution theory and activated state theory which have been proposed to describe gas sorption and diffusion in miscible blends. The negative deviation of gas permeabilities for the blends from this rule can be explained semiquantitatively by free volume theory which takes volume contraction on mixing into account. The negative deviation increases with gas molecular size which results in larger ideal gas separation factors than that calculated from the additivity rule. For He/CH 4 and H 2 /CH 4 pairs, the permselectivities for the blends are higher than that for either pure TMPC or SAN. The deviation from additivity for gas transport properties of TMPC/SAN blends is the opposite of that observed in the first paper of this series for PMMA/SAN blends. This can be attributed to the stronger interactions in TMPC/SAN blends than in PMMA/SAN blends.