Terpolymeric resins (2,2′-DHBPBDF) (DHBP = dihydroxybiphenyl; BD = butylenediamine; F = formaldehyde) were synthesized by the condensation of 2,2′-DHBP, 1,4-BD and formaldehyde in the presence of an acid catalyst with varied molar ratios of reacting monomers. Resin composition was determined on the basis of its elemental analyses. Their number-average molecular weight was determined by conductometric titration in non-aqueous media. The viscosity measurements were carried out in N,N-dimethylformamide at room temperature. Ultraviolet–visible, infrared and proton nuclear magnetic resonance spectral studies were undertaken to elucidate the structure of these resins. The thermal stability and kinetics of the thermal decomposition of these newly synthesized resins have been evaluated on the basis of thermogravimetric analysis and differential thermal analysis. The ion-exchange properties of these resins were studied for different metal ions. A batch equilibrium method was employed to study the selectivity of metal ion uptake. The study was carried out over a wide range of pH and ionic strengths of different electrolytes.