Olefins glassy polymer

Thus, the permeation of hydrocarbons in polymer membranes is governed by the basic regularities typical of permeation of low MW penetrants, modified however by certain peculiarities related to the stmcture and shape of hydrocarbon molecules. We will now discuss the physicochemical regularities of hydrocarbon separation and removal using polymer membranes, by trying to reveal the relationship between the chemical stmcture of polymers and their separation properties with respect to mixtures containing hydrocarbons. It follows from literary data that mbbery polymers are mainly used in gas/vapor separation processes for selective separation of hydrocarbon vapors from their mixtures with air as well as in pervaporation processes for the removal of hydrocarbons from their aqueous solutions. In practice, glassy polymers are used for separation of olefins and paraffins as well as for separation of aromatic, ahcyclic, and aliphatic hydrocarbons. 

Comparative Permeability of C2, C3, and C4 olefins. It is interesting to compare permeability, diffusion, and solubility coefficients of various olefins, as well as ideal olefin/paraffin selectivity in a glassy polymer. Such comparison can be made,... 

Thus, it follows from the above data that glassy polymers are promising materials for selective separation of olefins from their mixtures with paraffins. The main contribution to the high values of permselectivity is made by the diffusion component ao- However, unsaturated bonds in olefin molecules make them capable of specific interactions with ir-conjugated polar... 

It has been shown that olefin/paraffin selectivity of glassy polymer membrane materials was mainly of diffusive nature." Indeed, with the pressure and temperature conditions currently used in the literature, sorption isotherms of C2/C3 olefins and paraffins in glassy polymer are very similar." " " 114,125... 

Several studies concerning the separation of propylene from propane base on faujasite (FAU zeolite) membranes or titanosilicate ETS have been published recently. The olefin/paraffin selectivity of all those materials was comparable to glassy polymers and always below 10. 

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