Carboxylation of unsatd polymers - by reaction with a carboxy-substd 4-phenyl-1,2,4-triazoline-3,5-dione

摘要

COOH gps. are introduced into unsatd. polymers by reaction with a COOH-substd. 4-phenyl-1,2,4-triazoline-3,5-dione (I). Suitable polymers have allyl H atoms, pref. with acyclic unsatn., including natural rubber, butyl rubber, polyisoprene, polybutadiene and unsatd. terpolymers of ethylene/propylene with polyunsatd. monomers. Cpds. (I) are pref. prepd. by (a) reacting an alkyl amino-benzoate with COCl2, splitting off HCl, reacting the resulting isocyanate with an alkyl hydrazinecarboxylate, cyclising the adduct with alkali, opt. converting into free acid or alkyl ester, and oxidising the resulting COOH-substd. 4-phenyl-1,2,4-triazolidine-3,5-dione.