Phosphonates as alternative to tributyl phosphate for the separation of actinides from fission products

Abstract

The present work investigates the role of increase in the basicity of organophosphorus extractant (dialkylalkyl phosphonates) on the uptake of actinides and fission products vis-à-vis tributyl phosphate (TBP), currently employed as a universal extractant. Two dialkylalkyl phosphonates viz. dibutylpropyl phosphonate (DBPrP) and dibutylpentyl phosphonate (DBPeP) were synthesized, characterized and evaluated for their solvent extraction behavior towards U(VI), Th(IV), Eu(III) and Tc(VII) in nitric acid medium ranging from 0.01-6 M. It was observed that increasing the basicity of the phosphoryl oxygen enhanced the uptake of the actinides and the distribution coefficient values were significantly larger as compared to TBP. The limiting organic concentration (LOC) value was estimated for Th(IV) for these extractants and compared with the TBP system. The separation factors of actinides with phosphonates over Tc(VII) are distinctly better than that with TBP.

Synthesis of Polyether, Poly(Ether Carbonate) and Poly(Ether Ester) Polyols Using Double Metal Cyanide Catalysts Bearing Organophosphorus Complexing Agents

“…The results indicate that the type of substituent, particularly the alkoxy group, influences the catalyst activity. Another reason for the decreased activity is the closely related characteristics of the substituents attached to the phosphorus atom and the basicity of oxygen in the phosphoryl group, as demonstrated in other experiments [40]. The DMC catalysts prepared with DMMP under various conditions showed no activity for the ROP of PO, suggesting that DMMP may not effectively interact with the To investigate the impact of co-complexing agents (co-CAs) on DMC, active organophosphorus compounds P(OEt) 3 , DEP, and TEP were prepared with and without co-CAs.…”

“…The results indicate that the type of substituent, particularly the alkoxy group, influences the catalyst activity. Another reason for the decreased activity is the closely related characteristics of the substituents attached to the phosphorus atom and the basicity of oxygen in the phosphoryl group, as demonstrated in other experiments [ 40 ].…”