The high molecular weight condensation polymers(CEP-1) of dibenzo-18-crown-6(DB-18-C-6) with sebacic acid were good membrane-forming material

which had higher complex selectivities to K+

but the permeabilities of the membranes were low.The permeabilities can be improved greatly when CEP-1 was mixed with a little water-soluble poly(vinyl pyrrolidone)(PVP).The experimental result showed that CEP-1/PVP membranes have high complex rate

complex ability

complex selectivity to K+.The DMA spectra indicated that the modulus[E] and tangent of the loss angle(tanδ)

were changed

therefore the CEP-1/PVP blends were partially compatible system.It has been found that the amount of PVP dissolved from CEP-1/PVP membrane were increased with temoerature of water solution raising.