NEW BIFUNCTIONAL ANION-EXCHANGE RESINS FOR NUCLEAR WASTE TREATMENT

Additional(1) bifunctional: anion-exchange resins have been designed, synthesized and evaluated for their ability to take up Pu(IV) from nit ric acid solutions. Bifunctionality is achieved by adding a second ani on-exchange site to the pyridine nitrogen (also an anion-exchange site ) of the base poly(4-vinylpyridine) resin. Previous work focused on th e effect of varying the chemical properties of the added site along wi th the length of an alkylene 'spacer' between the two sites. Here we e xamine four new 3- and 4-picolyl derivatives which maintain more rigid ly defined geometries between the two nitrogen cationic sites. These m aterials, which have the two anion-exchange sites separated by three a nd four carbons, respectively, exhibit lower overall Pu(IV) distributi on coefficients than the corresponding N-alkylenepyridium derivatives with more flexible spacers. Methylation of the second pyridium site re sults in a ca. 20% increase in the Pu(IV) distribution coefficients.