Collect. Czech. Chem. Commun. 1985, 50, 834-839

The equilibrium acidity of cyclic and linear amides and its effect on the anionic polymerization of lactams

Bohumír Valtera, M. I. Terekhovab, E. S. Petrovb, Jaroslav Stehlíčeka and Jan Šebendaa

a Institute of Macromolecular Chemistry, Czechoslovak Academy of Sciences, 162 06 Prague 6, Czechoslovakia
b Karpov Institute of Physical Chemistry, 107 120 Moscow B-120, U.S.S.R.


The equilibrium acidity of lactams with rings of various size and of linear N-substituted amides was measured in dimethyl sulfoxide by the spectrophotometric method. The pK values of these NH-acids thus determined varied in the range 22-27. The data are used to characterize the acidobasic equilibrium between the amide groups of the monomer, polymer and their N-anions during the anionic polymerization of lactams. The effect of acidity on the anionic copolymerization of lactams is also discussed.