Extraction dibutyl

In spite of their high volatility and water extractability, dibutyl phthaiate and di-isobutyl phthaiate continue to be used in PVC. They are efficient plasticisers and their limitations are of greatest significance in thin sheet. 

In typical processes, the gaseous effluent from the second-stage oxidation is cooled and fed to an absorber to isolate the MAA as a 20—40% aqueous solution. The MAA may then be concentrated by extraction into a suitable organic solvent such as butyl acetate, toluene, or dibutyl ketone. Azeotropic dehydration and solvent recovery, followed by fractional distillation, is used to obtain the pure product. Water, solvent, and low boiling by-products are removed in a first-stage column. The column bottoms are then fed to a second column where MAA is taken overhead. Esterification to MMA or other esters is readily achieved using acid catalysis. 

Poly(vinyl chloride) has a good resistance to hydrocarbons but some plasticisers, particularly the less polar ones such as dibutyl sebacate, are extracted by materials such as iso-octane. The polymer is also resistant to most aqueous solutions, including those of alkalis and dilute mineral acids. Below the second order transition temperature, poly(vinyl chloride) compounds are reasonably good electrical insulators over a wide range of frequencies but above the second order transition temperature their value as an insulator is limited to low-frequency applications. The more plasticiser present, the lower the volume resistivity. 

When analysing these different lists one realises that the different sources do not agree with each other. So far as the NFPA reactivity code is concerned, codes 2 and 3 have been attributed to epoxides and ethers that are unsaturated. Their purpose is to inform the reader about dangerous polymerisation and not peroxidation risks. The accidents described below also involve compounds such as dibutyl ether that are not considered as dangerous in the regulations or NFPA Extracting a fatty substance and a floor wax with diethyl ether gives rise to a detonation. 

Figure 2. Effect of hot (100 0 water extraction on impact strength of PP in the absence and presence of a combination of conventional antioxidants (Nickel dibutyl dithiocarbamate and Irganox 1076, NiDBC+irg.1076) and a thiol bound antioxidant (3), Bound AO. (Reproduced with permission from Ref. 13. Copyright 1983 App. Sci. Pub.)...

Liu, M. Zhang, S. Sun, S. The industrial practice of utilizing dibutyl carbitol in solvent extraction of gold. Kuangye Gongcheng 1995, 15, 37 10. 

Butex A process for separating the radioactive components of spent nuclear fuel by solvent extraction from nitric acid solution, using diethylene glycol dibutyl ether (also called Butex, or dibutyl carbitol) as the solvent. Developed by the Ministry of Supply (later the UK Atomic Energy Authority) in the late 1940s. Operated at Windscale from 1952 until 1964 when it was superseded by the Purex process. 

Dibutyl telluride (typical procedure) Hydrazine hydrate 80% (0.50 ml., 7.1 mmol) is added dropwise using a syringe to a stirred mixture of finely ground Te (0.64 g, 5 mmol) and powdered NaOH (0.40 g, 10 mmol) in DMF (10 mL) at 50-60°C. After 3 h stirring, n-butyl bromide (1.4 g, 10 mmol) in DMF (2 mL) is added, the mixture is heated at 60°C for a further 30 min, cooled at room temperature and extracted with petroleum ether (40-60°C). The organic phase is separated, washed with HjO, dried (CaClj) and evaporated, giving the pure telluride (0.69 g (57%) b.p. 111-114°C/13 torr). 

Fig. 10. GC MS TIC traces for total extracts of (a) a tropical lake sediment, and (b) epicu-ticular wax from a dominant reed growing in the shallow areas of the lake (analyzed as TMS). Numbers and symbols as in Fig. 9, 4P = dibutyl phthalate contaminant, IS = internal standard.

The molecules producing coordinative saturation need not be chelating. As a by-product to the study of synergism in the extraction of alkali metal chelate salts, Healy (14) isolated crystalline complexes Li(PhCO-CHCOPhJSa where S = tri-n-octylphosphine oxide or N, N-dibutyl-acetamide. 

Dibromoethylene, irradiation of, 5 156 Dibromomethylarsonic acids, 44 221 Dibromomethylsulfonium salts, 35 262 Di-(-butyldichlorosiIane, reactions, with lithium phosphides, 31 181-186 Dibutyl phosphonic acid, in liquid-liquid extraction, 9 34-35, 36-37... 

Determination of Mg in the hard tissues (shell and pearl) of shellfish by the ICP-AES method involves dissolution of the sample by hot concentrated nitric acid, hydrochloric acid and perchloric acid. However, the large excess of Ca in the matrix strongly interferes with the end analysis and causes damage to the torch. After adjusting the pH to 4.5, the Mg ions were extracted by a 0.01 M solution of 3-methyl-l-phenyl-4-trifluoroacetylpyrazol-5-one (16) in dibutyl ether and the ICP-AES analysis was carried out by direct injection of the organic solution. ... 

The primary separation of plutonium and uranium from the fission products involves a solvent extraction with 30 vol % TBP at room temperature. The activity levels in this separation are quite high ( 1700 Ci/L for the fission products) and the aqueous waste, which contains 99+% of the fission products, is a high-level waste. Am and Cm are not extracted and Np is partially extracted. Because of the high radiation levels, there are radiolysis problems with TPB, leading to solvent degradation. Primary products of the radiolysis of TBP are the dibutyl- and monobutylphosphoric acids along with phosphoric acid. These degradation products are removed in the solvent purification steps. 

For dibutyl carbitol, spectrophotometric and other data234 have been interpreted in terms of the formation of species such as [H+(H20)4(DBC)n]AuCl4-. Since the PGM themselves are not extracted to any significant extent by these extractants, useful separations of gold from other precious metals can be made readily. 

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