High activity vapor, polymer transport

High Activity Vapor and Liquid Transport in Semicrystalline Rubbery Polymers... 

The sorption of organic vapors at high activities has been reviewed in recent papers " At low concentrations, dual mode sorption takes place in assy polymers as described later in this review. The effects of crystallinity and variable morphologies on gas and vapor transport in polymer blends will not be discussed here but an excellent review may be found in the literature ... 

Miscible polymer blends offer a physical method for tailoring properties to obtain combinations that may be more desirable than those of either component polymer. The water sorption and transport behavior of miscible polymer blends have been examined in several studies. For example, Schult and Paul [12] investigated the water sorption and transport properties of homogeneous blends of PVP, a water-soluble polymer that is miscible with a relatively hydrophobic bisphenol A polysulfone (PSF) over the entire composition range. Unfortunately this study was restricted to blends containing <40% PVP, since blends containing >40% PVP would phase-separate when exposed to high water vapor activities. Such phase-separation is driven by the fact that one polymer wishes to swell or dissolve in water, while the other does not. 

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