Of p-dioxane

WHO (1993) Guidelines for Drinking Water Quality, 2nd Ed., Vol. 1, Recommendations, Geneva Woo, Y.T., Arcos, J.C., Argus, M.F., Griffin, G.W. Nishiyama, K. (1977a) Structural identification of p-dioxane-2-one as the major urinary metabolite of p-dioxane. Naunyn-Schmiede-... 

J. B. Ott, J. R. Goates, and N. F. Mangelson, Solid-Liquid Phase Equilibria in Binary Mixtures of p-Dioxane with CCI4, CBrClj, and CFCI3. Solid Compound Formation in the CCI4 and CFCI3 Systems , J. Chem. Eng. Data, 9, 203-206 (1964). 

Dissolve 100 grams of 2,4,6-trinitrotoluene into 200 milliliters of p-dioxane, and then place the mixture into a cold-water bath. Then stir the mixture, and add 2 milliliters of 28 - 30% ammonium solution. Then bubble 46 grams of hydrogen sulfide gas into the mixture over a 2-hour period while keeping the reaction temperature at 20 Celsius by means of the cold-water bath, and stir the reaction mixture continuously during the addition. After the addition of the hydrogen sulfide gas, filter off the precipitated sulfur, and then add the filtered reaction mixture to 1000 milliliters of ice water. After which, filter off the yellow precipitated solid, and then wash the solid with 400 milliliters of water. Then vacuum dry or air-dry the solid. The result is a mixture of the desired 4-amino-2,6-dinitrotoluene (61%), and the by-product, 4-hydroxylamino-2,6-dinitrotoluene (39%). 

Figure 16. Stressed polystyrene after application of p-dioxane...

Ethyldioxane (IJ) was a product of the reaction of p-dioxane with ethylene in the presence of hydrochloric acid and di-t-butyl peroxide at 130-140 C (Expts. 29 and 30). However, the major product was bis-(2-chloroethyl) ether ( ) and a smaller amount of... 

In the absence of hydrochloric acid, telomeriration occurred, yielding very high molecular weight telo-mer (Expt. 28). Hanford and Roland (3) found that the benzyl peroxide-induced reaction of dioxane with ethylene at 80 C resulted in products formed by reaction of 54 mols of ethylene per mol of p-dioxane. In Expt. 28 using di-t-butyl peroxide at 130 -140 14 mols of ethyl-... 

Ethylene and formaldehyde are the main products from oxetane (91). Preliminary quantum yield values of some products from p-dioxane (186) and the tetrahydrofurans (188) are presented in Tables 14 and 15. In the case of p-dioxane one is led to propose... 

The methods routinely used for preparing hydrazones of aldoses yield only a gel-like, orange mass from D-fructose and (2,4-dinitrophenyl)-hydrazine. i However, by use of p-dioxane containing catalytic proportions of water (3%) and hydrogen chloride (0.3%), small needles of the p-dioxane solvate are obtained after 5 minutes. Dissolution of these crystals in 1 1 pyridine-96% ethanol gives the pyridine solvate. These crystals (m.p. 173-175°) were found to belong to the monoclinie system, elongated parallel to the 5-axis. ... 

Combining (1-10) and (1-11) to eliminate Xf and solving for X, we find that the mass ratio of p-dioxane to water in the exit water phase is given by... 

To what extent can the extraction of p-dioxane be increased by adding additional stages in cocurrent, crosscurrent, and countercurrent arrangements ... 

With = 2.4, X is computed to be 0.0302, which corresponds to an overall 90.93% extraction of p-dioxane from water to benzene. A higher degree of extraction than this could be achieved only by increasing the benzene flow rate. 

With X = 113 and = 2.4, (1-19) gives Xj = 0.0364, which corresponds to 89.08% overall extraction of p-dioxane. In general, for N countercurrent equilibrium stages, similar combinations of stage equations with X = 0 lead to the equation... 

Values of overall percent extraction are plotted in Fig. 1.15 for up to five equilibrium stages, at which better than 99% extraction of p-dioxane is achieved. The limit of (1-20) as depends on the value of as follows. 

Caution Stott (Parish Chem. Co.) has reported the occurrence of a severe explosion in the purification of 18-crown-6 according to the procedure of Cram, Liotta, and co-workers (5, 152), probably due to formation of p-dioxane. Some precautions are suggested in the report. 

They examined two methods of separating the additives from the polymer. GC of a hexane extract of the polymer produced numerous extraneous peaks, probably owing to a decomposition of dissolved amorphous polymer in the injection port, rendering the chromatogram useless. When the polymer was dissolved in p-xylene and re-precipitated with an equal volume of p-dioxane, a relatively clean chromatogram was obtained from the filtrate. The position of decomposition peaks from unstable compounds, such as dilauryl 3,3 -thiodipropionate and distearyl pentaerythritol diphosphite, are predictable and do not interfere with the determination of those additives studied by Lappin and Zannucci [5]. 

Unknown 4.14. Ionization from a nonbonding electron orbital can also trigger such ring fragmentations. Predict an abundant odd-electron fragment ion in the mass spectrum of p-dioxane. 

---