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Neodymium molar concentration

TOTAL NEODYMIUM MOLAR CONCENTRATION IN THE ORGANIC PHASE... [Pg.338]

Figure 5. Total neodymium molar concentration in the organic phase as a function of the equilibrated HDEHP-dimer molar concentration... Figure 5. Total neodymium molar concentration in the organic phase as a function of the equilibrated HDEHP-dimer molar concentration...
The calculated free equilibrium HDEHP dimer concentration using Equation 12 is illustrated in Table VI. The relationship of the equilibrated HDEHP dimer molar concentration with the total neodymium concentration and the total nitrate concentration in the organic phase is shown in Figures 5 and 6, respectively. [Pg.335]

The f-transition metal catalysts were first described by von Dohlen [98] in 1963, Tse-chuan [99] in 1964 and later by Throckmorton [100]. In the 1980s Bayer [14] and Enichem [101] developed manufacturing processes based on neodymium catalysts. The catalyst system consists of three components [102] a carboxylate of a rare earth metal, an alkylaluminum and a Lewis acid containing a halide. A typical catalyst system is of the form neodymium(III) neodecanoate/diisobutylaluminum hydride/butyl chloride [103]. Neodymium(III) neodecanoate has the advantage of very high solubility in the nonpolar solvents used for polymerization. The molar ratio Al/Nd/Cl = 20 1 3. Per 100 g of butadiene, 0.13 mmol neodymium(III) neodecanoate is used. With respect to the monomer concentration, the kinetics are those of a first-order reaction. [Pg.310]

Trivalent cations of REE in aqueous solutions, acidified with HCl, HNO3, or HCIO4, absorb in the UV or VIS. The absorption bands are narrow, with sharp, non-overlapping peaks, but the molar absorptivities are rather small (1-10), and individual species of REE can be determined at concentrations of the order of 1 mg/ml [120]. Higher sensitivities are obtained after the ions have been converted into EDTA complexes [121]. The determination can be made more selective and sensitive by the use of the derivative spectrophotometry techniques [122-124]. Neodymium and erbium have been determined in the mixtures of REE by the derivative spectrophotometry technique using ferron and diethylamine [ 125]. [Pg.345]

Most of the above mentioned results and in particular the differences among 4f and d elements still must be explained. If we look at the molarities involved in the polymerization reaction we obtain no further information. Different reaction orders are reported in the literature while a first order is found on both butadiene (25, 27) and isoprene (25, 37, 38) homopolymerization, first (25) and second (33) order (with respect to total monomer concentration) are indicated in the case of copolymerization. As for the catalyst, the reaction order appears to range between 0.5, as for the tris(benzyl)-neodymium (15), and 1 (33) or 1.7-1.75 (37, 38) for the multicomponent system. [Pg.397]


See other pages where Neodymium molar concentration is mentioned: [Pg.158]    [Pg.6]    [Pg.14]    [Pg.112]    [Pg.8]    [Pg.60]    [Pg.872]    [Pg.9]   


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