Polymer modification of Resorcinol-Formaldehyde (R-F) ion-exchange resin

Resorcinol-Formaldehyde (R-F) resin is a candidate regenerable ion-exchange resin for removal of radioactive cesium from highly alkaline waste tank supernates at both the Hanford and Savannah River sites. Previous investigations into the structure/function relationships of R-F resin have shown that the R-F resin undergoes facile oxidation to produce para-quinones, with loss of ion-exchange sites, hence lowered performance of the resin for cesium ion-exchange. In this report, we give the results of our studies into polymer resins prepared using 4-methylresorcinol and 4-fluororesorcinol. The reaction of 4-methylresorcinol with formaldehyde formed oligomeric structures, while a mixture of 4-fluororesorcinol, phenol, and formaldehyde produced a non-soluble resin in aqueous/alkaline conditions. The 4-fluororesorcinol resin underwent significant nucleophilic displacement of the fluorine substituent to give oxidized resins with lower ion-exchange performance