Polymerization of lactams, 84. Anionic polymerization of lactams accelerated with N-iminolactams, 3. The role of 1-(1-pyrrolin-2-yl)-2-pyrrolidone in the anionic polymerization of 2-pyrrolidone

The anionic polymerization of 2-pyrrolidone was accelerated with 1-(1-pyrrolin-2-yl)-2-pyrrolidone (1) , labelled with nuclide ¹⁵N. The incorporation of 1 into the polymer was followed by the change of isotope concentration, and the apparent rate constants were derived for some elementary reactions in the investigated polyreaction. The interchange reaction between 1 and monomer was also measured. 1 can be considered a slow activator, each molecule incorporating into the polymer being the precursor of a growth centre.