
268 HIGH PERFORMANCE POLYMERS
11.3.5 Gas Permeability
Organic polymers have a comparatively high gas
permeability. In Table 11.7, the permeability of some
polymers is compared. The gas transport properties in
PEN are dependent on the degree of crystallinity [70].
Table 11.7 Oxygen Permeability of Some Polymers
[71]
Polymer P
a
Poly(ethylene), low density 2500
Poly(ethylene), high density 500
Poly(styrene) 2000
Poly(vinyl chlor ide) 5.9
Poly(acrylonitrile) 5
Ther motropic liquid crystalline polymers 0.4
Poly(ethylene terephthalate) + SiO
x
12 nm 0.15
a
P: Permeability/10
16
Std cm
3
cm cm
−2
s
−1
Pa
−1
.
A decrease ofthe permeability is observed at thermally
crystallized