In an alkaline polymerization, N-substituted S-ketoamides behave as activators. The strongest activation effect has been observed with S-ketoamides containing no hydrogen atom on the (X-carbon. In the formation of the growth centres the decisive role can be attributed to the ketoamide N-anion, which probably undergoes cleavage to isocyanate and l (etone. The formation of growth centres by the addition of isocyanates to lactam or its ...
