“…First of all attention was turned to heat-resistant polyheteroarylenes -sulfonated polyetheretherketones (SPEEK) [13,98,101,113], sulfonated polyethersulfones (SPES) [13,37,93,98], sulfonated polyethers (SPE) [89], and sulfonated polyimides (SPI) [102]. In addition to them ionomers with an aliphatic main chainpolystyrene and its copolymers [100,103], polyvinyl alcohol (PVA) [36,62,99], polyacrylic acid [62], polyallylamine [56] have also been subjects for insertion.…”