Patent ID: 8354492

Claim:
A system, comprising: a) at least one catalyst capable of anionic polymerization of lactams selected from the group consisting of alkali metals, alkali metal salts of lactams, alkali metal hydrides, alkali metal alcoholates, alkali metal hydroxides and organo-metallic compounds; and b) at least one activator capable of anionic polymerization of lactams, wherein the at least one activator is a uretdione based on 1,4-cyclohexyl diisocyanate, hexamethylene-1,6-diisocyanate, isophorone diisocyanate, 1,4-cyclohexyl diisocyanate, 1,1-methylene-bis-(4-isocyanatocyclohexane), 1,2-bis-(9-isocyanatononyl) -3-heptyl-4-pentylcyclohexane, tetramethylxylylene diisocyanate, 4,4′-methylene diphenyldiisocyanate, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 1,5-naphthylene diisocyanate,1,3-bis-(3-isocyanato-4-methylphenyl)-2,4-dioxodiazetidine, and/or N,N′-bis-(4-methyl-3-isocyanatophenyl)-urea.