The viscosity behavior of the sulfonated polystyrene lanthanum ionomers(SPS La) has been investigated in comparison with the sodium and zinc ionomers in polar solvents. The results indicated that the SPS La with the same sulfonation degree exhibited higher reduced viscosity and intrinsic viscosity when the polarity of the solvents was high. The lower the sulfonation degree of SPS La, the higher the reduced viscosity of SPS La, especially in case of estremely dilute dolutions. The order of the reduced viscosity and the polyelectrolyte effect tendency are:SPS Na>SPS Zn> SPS>SPS La .
