This paper describes an apparatus for measuring both pure and mixed gas sorption in amorphous polymers. Sorption data were reported for pure gases (CO2

CH4

C2H4 and C2H6) in three amorphous polymers[poly(methal methacry-lateXPMMA)

pplyimde(PI) and poly(vinyl acetate) (PVA)]. These results and some data reported in literature show that the sorption model developed in Part I of this series can be applied to amorphous polymers both above and below the glass-transition temperature and that the model parameters can be correlated with the molecular properties and characteristics of the polymers and penetrant.