Blocking nitrosamine formation with polymers

A set of polymers have been synthesized in order to determine whether polymers containing nitrosation-reactive functional groups could effectively block nitrosamine formation. Polymers containing both hydrophobic backbones [poly[(chloromethyl)styrene], poly(ethylene oxide-co-epichlorohydrin), chloromethylated cross-linked polystyrene] and hydrophilic backbones [poly(ethylenimine) and poly(acryloyl chloride)] have been derivatized with pyrrole, 2,5-dimethylpyrrole, 2-[(methylamino)methyl]pyrrole, or hydroquinone. All of these polymers, as well as PEI itself, are effective at blocking the nitrosation of morpholine by nitrous acid. The hydrophilic polymers are much better able to compete for the available nitrosating agent in aqueous solution than are the hydrophobic polymers. Nevertheless, all of the polymers were highly effective in scavenging nitrous acid from aqueous solution prior to addition of the amine. The reaction products derived from the reactive, polymer-attached functional groups are retained on the polymer and are easily removed from mixtures of chemicals by physical means. Since nitrosamines and other N-nitroso compounds are known to be potent animal carcinogens, this work is of significance in the area of preventive chemical toxicology.