REACTIONS ON POLYMERS WITH AMINE GROUPS - V - ADDITION OF PYRIDINE AND IMIDAZOLE GROUPS WITH ACETYLENECARBOXYLIC ACIDS

Unsaturated macromolecular carboxybetaines were obtained by reaction o f poly(4-vinylpyridine) and poly (N-vinylimidazole) with propiolic aci d. A kinetic model was presented for 4-methylpyridine. It consists of three coupled reactions: neutralization, addition which involves two m olecules of acid and leads to a cation-anion pair structure, where the cation results from the addition of the amine nitrogen to the triple bond of acid, and an equilibrium reaction between the ion-pair structu re and the betaine structure. The addition rate was found to be higher for poly(4-vinylpyridine) than for poly (N-vinylimidazole); it was al so higher in water than in a water-methanol mixture. The reaction with acetylenedicarboxylic acid was carried out on poly(N-vinylimidazole), but the transformed units showed the structure that results from prop iolic acid. The betaine products from 4-methylpyridine did not polymer ize by radical initiation. The polymeric products show characteristics of photocrosslinking polymers. (C) 1998 John Wiley & Sons, Inc.