C. Park et al., Morphological effect of dispersed phase on gas permeation properties through heterophase polymer membrane: theoretical and experimental approaches, POLYMER, 41(5), 2000, pp. 1765-1771
The possibility of the continuous channel formation of the dispersed phase
in immiscible polymer blends was numerically simulated by adopting the perc
olation concept. The numerical simulation showed that the formation probabi
lity of the continuous channels increased with the increase in the amount o
f the dispersed phase. Further, it increased with the decrease in the domai
n size of the dispersed phase at a given blend composition. The effect of t
he presence of the continuous channels of the dispersed phase across the me
mbranes on gas transport properties was investigated experimentally. The do
main size of the dispersed polyisoprene phase of poly(phenylene oxide)/poly
isoprene (PPO/PI) blend membranes was controlled by adding the styrene-isop
rene-styrene (SIS) block copolymer. When the SIS block copolymer was added
at 4 wt% in PPO/PI membranes in the range of the PI content of 20-30 wt%, t
he domain size of the dispersed phase was reduced markedly and its permeabi
lity was consequently increased. From the theoretical and experimental resu
lts, it could be concluded that the abrupt increase in gas permeability of
the blend membranes at 20-30 wt% of PI phase may result from the formation
of the continuous channels of the more permeable dispersed phase when the b
lock copolymer is added. (C) 1999 Elsevier Science Ltd. All rights reserved
.