Solution spinning Solvent extraction

Hubert Tschamler They were derived either from mean values observed for model compounds of known structure or from the properties of solvent extracts of coals. In the latter case an accurate value for %H i can be derived by measuring proton spin resonance in solution and this, combined with the optical densities observed in the infrared spectra, gives the specific extinction coefficients. (See J. F. M. Oth, E. de Ruiter and H. Tschamler, Brennstoff-Chem. 42, 378 (1961) also Ref. 7). 

The study of frozen aqueous solutions of iron(III) compounds is only of limited value because of the tendency to hydrolyse, and the relaxation broadening [63, 128], and little work has been done. A potentially more profitable application is the study of solvent extracts. Frozen nitrobenzene extracts of iron(III) in HCl, HBr, and NaSCN solutions contain respectively the FeCl4 and FeBr4 anions and a 6-coordinate complex Fe(NCS)4X2 (X is either water or nitrobenzene) [129, 130]. The spin-spin relaxation behaviour is dependent on the solvent, and trioctylphosphine oxide extracts show partially resolved hyperfine structure. 

For lyotropic liquid crystalline polymers, either wet-spinning or dry-jet-wet spinning are employed to produce fibers. A lyotropic state of a polymer solution is formed at a specified concentration and temperatnre in a nonvolatile solvent. The anisotropic polymer solution is extruded into a non-solvent bath, where fiber coagulation and solvent extraction take place. For thermotropic liquid crystalline polymers, a melt spuming method is applied. 

N-Cyclohex-l-enylpyrrolidine (9 g 0 06 mol) was dissolved in pentane with A -ethyldiisopropylamine (7.8 g 0.06 mol). Perfluorohexyl iodide (13.4 g, 0.03 mol) IS added to the solution. Aprecipitate of A-ethyldiisopropylamine hydroiodide IS formed instantly After 3 h, the precipitate is filtered off, and the solution is evaporated The crude liquid is hydrolyzed with 6 mL of 40% sulfuric acid The mixture is stirred for 3 h and extracted with ether. The ether layer is neutralized with aqueous sodium hydrogen carbonate, washed with water, and dried over magnesium sulfate. The solvent is evaporated, and the residue is distilled. A second distillation with a spinning-band column yields 7 9 g (63%) of pure 2-(perfluoro-hexyl)cyclohexanone (bp, 71 -73 °C at 0 4 mm of Hg). 

C. 1-Hexanol. To a solution of trihexylborane in a 500-ml. three-necked flask [prepared from 25.3 g. (0.30 mole) of 1-hexene in 150 ml. of tetrahydrofuran and 84 ml. of a 1.20ilf solution of borane in tetrahydrofuran, as described in Section A] is added 34 ml. (0.10 mole) of a 3N solution of sodium hydroxide. This is followed by the dropwise addition of 36 ml. (0.35 mole) of 30% hydrogen peroxide solution at a rate such that the reaction temperature is maintained at approximately 35° (water bath). After being stirred at room temperature for one hour, the mixture is poured into 100 ml. of water. The organic phase is separated and the aqueous phase is extracted with 50 ml. of ether. The combined organic extracts are washed with three 50-ml. portions of saturated brine solution and dried over Drierite. After the bulk of the solvent is removed by distillation, the residue is fractionated with a 24-in. Teflon spinning band column (Note 10) to provide 7.7-8.2 g. (25.1-26.7%) of 1-hexanol of 95% purity, b.p. 145-153° and 10.1-15.4 g. (33.3-50.3%) of pure 1-hexanol, b.p. 153-155° (Note 11). The total yield of material with >95% purity is 58.4-77%. 

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