We have already found that the polymers, which are obtained by the polymerization of 4-vinylphenyl isothoiocyanate after the zwitterion formation with cyclic amidines, are networked through the ionic interaction among the zwitterions becoming insoluble to various solvents. We report here on the results of the reaction of nucleophilic reagents such as amines and alcohols with the zwitterionic adduct to investigate about the decrosslinking through the resolution of ionic interactions. In the model reactions of amines and alcohols with the zwitterion compounds, which were consisted of the phenyl isothiocyanate and cyclic amidines, the reaction of nucleophilic reagents and zwitterionic adducts having methyl group at the 2-position of the amidine proceed quantitatively. Based on the model reaction, such nucleophilic addition was applicable to decrosslinking reaction of the networked polymers containing the zwitterion structure in the side-chain. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019