extractants such as N, N-di(2-ethylhexyl)butanamide (DEHBA) and N, N-di(2-ethylhexyl)hexanamide (DEHHA) having a linear alkyl chain on carbonyl carbon atom have been found efficient for the liquid-liquid extraction of uranium at low pH(1-3) in the presence of Pu(IV) .
Sulphamic acid (H2NSO3H) is the monoamide
of sulphuric acid and is formed as orthorhombic crystal.
Benzoic acid B is present and also all conceivable methylated derivatives DAM[e.sub.1-4] and BDAM[e.sub.1,2] of the diamine DA and of the monoamide
In water solution anhydrides rapidly react with ammonia or primary or secondary amines to form a monoamide
, monocarboxylic acid group, which is commonly referred to as an amic acid (see Figure 2).
The polycondensation of diamines and diesters stops early at the stage of oligoamides because it does not only yield the expected monoamide
units BDA and, from those, the chain forming diamide units [B.sub.2]DA, but also methylated units BDAMe and BDAM[e.sub.2] and acid units B.