Thermostable poly(p-phenylene sulfide sulfonic acid) as ion exchangers

Poly(p-phenylene sulfide sulfonic acid) was thermally crosslinked for use as a cation exchange polymer with high thermal stability. The decomposition temperature (T_d) of the polymer increases with an increase in the crosslinking temperature. The crosslinking reaction at 300°C in air resulted in the formation of a strongly acidic cation exchange polymer with a T = 467°C and having an SO₂ bond, whose crosslinked structure was investigated using IR spectroscopy.