Although the existence of Lewis acid-base interactions between CO2 and electron donating functional groups in polymers can be determined from the vibrational spectra of the polymers in question, only a few quantitative estimates of the strength of such interactions have been reported. We have previously reported values of the enthalpy of association between CO2 and the carbonyl group in polymers from the bending vibrations of CO2. In the present work, we extend these measurements to other functional groups and relate the strength of these interactions to the structure of the polymer. (C) 2014 Elsevier B.V. All rights reserved.