Studies of Ion Exchange Membranes. XXX. The Tetrahydrofuran Extraction of the Ion-exchange Membrane and Its Base Membrane Prepared by the “Paste Method”

In order to throw light on the chemical structure of the ion-exchange membrane prepared by the “Paste Method,” the ion-exchange membrane and its base membrane were extracted with tetrahydrofuran. The base membrane was composed of polyvinyl chloride and the resin component of the styrene-divinyl benzene system or of the 2-methyl-5-vinyl pyridine-divinyl benzene system, the ion-exchange group was introduced into this resin component. It was established that the resin component was partially extractable through a filter paper. Although the resin component and polyvinyl chloride should be entwined with each other, and although the resin component might be grafted on polyvinyl chloride, it could be concluded that the chemical structure of the ion-exchange membrane prepared by the “Paste Method” is different from that of Amberlite IR-120, i. e., the homogeneously crosslinked gel-structure.