Permeability of Small Molecules and Free-Volume Distribution

Permeability of Small Molecules and Free-Volume Distribution 

The distribution of free volume in amorphous polymers is of paramount importance for the respective material s transport behavior towards small and medium-sized penetrants. 

While in rubbery polymers differences in the segmental mobility can be more important than differences in the free-volume distribution for glassy polymers often certain basic correlations can be found between the permeability of small molecules and free-volume distribution. Other important factors are the molecular mobility of chain segments and the local chemical composition. 

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