The chemical reactions between polyacrylic acid (PAA) and various divalent metal oxides (MO; M = Ca, Mg, Cu, Zn) were studied by Fourier transform infrared spectroscopy (FTIR). The results show clear evidence of chemical bonding between the polymer and the metals as a result of their interaction. From the energy difference between the symmetrical and the asymmetrical bands of the various possible structures, monodentate metal-carboxylate bonding was found to be the most probable in all cases. Also, from the analysis of the corresponding molar relations, the particle size of the oxides was found to play an important role in the reaction.