Gas transport and sub-T, relaxations in unmodified and nitrated polyarylethersulfones
نویسنده
چکیده
Aromatic nitration has been used to modify the polymer mam chain of polysulfone and polyethersulfone Alteration m the gas separation charactenstlcs of homogeneous membranes made out of these polymers could be observed upon nitration Generally, separation factors for gas mixtures of CO&H, increased while the permeability decreased Remarkably, a decreasing dlffuslvlty for both gases upon nitration could not be correlated with an increasing free-volume but was interpreted as an drastically decreased main-chain flexlblhty The decrease of main-chain segmental moblhty could be venfied expenmentally by a dlmmlshed amount of B-relaxations determined by torsional braid analysis
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