Synthesis, characterization and evaluation of phosphoramides for actinide extraction

[Display omitted] •Two hexaalkylphosphoramide extractants (HPPA&HBPA) have been synthesized.•Phosphoramides extraction studies with U(VI), Pu(IV) and Th(IV) were compared with TBP.•The phosphoramides have lower density and lesser aqueous solubility than TBP. A new class of extractants called hexaalkylphosphoramides has been chosen for actinide separation applications in the present study. Hexaalkylphosphoramides [(NR2)3PO] are compounds which possess three nitrogen sub-units along with a strong donor oxygen atom. The studies on them provide an opportunity to synthesize a large variety of structurally diverse analogs. Thus, the desired properties of the extractant can be tuned for a specific application. We discuss the synthesis, purification, and characterization of two such hexaalkylphosphoramides (Propyl and Butyl) in this paper. Their physico-chemical properties were measured and the extraction behavior was evaluated with U(VI), Th(IV) and Pu(IV). The results were compared with trialkyl phosphates such as tri-n-butyl phosphate (TBP) and tri-n-amyl phosphate (TAP). The results revealed that the extraction behaviors of phosphoramides are comparable to trialkyl phosphates.