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Methane sulphonate/sulphonic acid

The benefits of the cerium methane sulphonic process are [132] (1) low cost, (2) methane sulphonic acid is unreactive with reactants and products, (3) stable to anodic and Ce(IV) oxidations, (4) high solubility of both Ce(III) and Ce(IV),... [Pg.162]

Ahmed Kabir etal. (1992) treated wood with DMDHEU as well as DMDHEU combined with a vinyl polymer, and determined the dimensional stability of the wood. Methane sulphonic acid was used as a catalyst in both cases. DMDHEU treatment resulted in a 50 % reduction in radial swelling following immersion in water for 100 minutes, with the combined treatment being snperior. However, the ASE (one cycle) of DMDHEU treated wood (30%) was snperior to that fonnd for the combined treatment (17%). DMDHEU appeared to be stable to hydrolysis over a number of wetting cycles. When DMDHEU-treated samples were exposed in ontdoor weathering trials, they exhibited considerable variation in moistnre content and developed severe surface checks, whereas the combined treatment showed snperior performance. [Pg.158]

FXeOSOjCF3 mw 299.37 colorl solid mp, decompn at RT if an excess of Xe difluoride is used in the prepn, the product will expld violently on warning to RT. Prepn is by reacting one mole of Xe difluoride with two moles of anhydr methane sulphonic acid initially at -110°, then completing the reaction at —63°... [Pg.396]

Both lyotropic and thermotropic liquid-crystalline synthetic polymers have been widely studied. Aromatic polyamides constitute the most important class forming liquid-crystalline solutions the solvents are either powerfully protonating acids such as 100% sulphuric acid, chloro-, fluoro- or methane-sulphonic acid, and anhydrous hydrogen fluoride, or aprotic dipolar solvents such as dimethyl acetamide containing a small percentage, usually 2-5 %, of a salt such as lithium chloride or calcium chloride. Such solutions constitute a nematic phase within certain limits. Some criteria for formation of a nematic instead of an isotropic phase are ... [Pg.66]

It is obvious that this type of suppresser column will have a limited lifetime but can be regenerated rapidly and easily by passing acetonitrile through it, followed by water. An example of the use of this type of suppression system is given in figure 4. It is seen that an excellent separation of the cations was achieved and the separation was carried out with 20 nM of methane sulphonic acid present in the mobile phase which was completely removed by the ion suppresser column. [Pg.231]

Tetramethylcyclohexanes.—An improved method for the preparation of j3-cyclocitral in purer form has been described. The methylsulphonate of a-cyclogeraniol (188) forms the cyclopropane derivative (189) with calcium carbonate, and this rearranges to a bicyclo[3,l,l]heptanol (190) with methane-sulphonic acid. Bohlmann and Zdero have found that the angelic acid ester of... [Pg.35]

Fig. 7.19 Time series (1987-1991) of weekly average concentrations of methane sulphonic acid (MSA), non-sea-salt-sulphate (nss-SCT) and ammonium (NHJ) measured at Mawson, Antartica. After Savoie et al. (1993), with kind permission of Kluwer Academic Publishers. Fig. 7.19 Time series (1987-1991) of weekly average concentrations of methane sulphonic acid (MSA), non-sea-salt-sulphate (nss-SCT) and ammonium (NHJ) measured at Mawson, Antartica. After Savoie et al. (1993), with kind permission of Kluwer Academic Publishers.
Fig. 7.24 150000-year record of methane sulphonic acid (MSA) concentration, non-sea-salt-sulphate (nss-SOj-) aerosol concentration and temperature reconstruction (from oxygen isotope data) from an Antarctic ice core. MSA and nss-SOj" aerosol concentrations are both high during very cold conditions, e.g. the last glacial period between 18 and 30 thousand years ago (see text for discussion). After Legrand et id. (1991). [Pg.275]

Fig. 6.26 Variations in proxy measurements for various climatic parameters in the Southern Ocean during the last glacial-interglacial cycle.MSA (methane sulphonic acid, a proxy for DMS) and 5lsO (proxy for temperature) in an eastern Antarctic ice core estimated iron concentration (Fe) and C02 trapped in air in another Antarctic ice core (Vostok) Corg = organic carbon (proxy for primary productivity) in an eastern tropical Pacific sediment core (after Turner et al. 1996). Fig. 6.26 Variations in proxy measurements for various climatic parameters in the Southern Ocean during the last glacial-interglacial cycle.MSA (methane sulphonic acid, a proxy for DMS) and 5lsO (proxy for temperature) in an eastern Antarctic ice core estimated iron concentration (Fe) and C02 trapped in air in another Antarctic ice core (Vostok) Corg = organic carbon (proxy for primary productivity) in an eastern tropical Pacific sediment core (after Turner et al. 1996).
Although the concept of the molecular composite was demonstrated by the work on PBT/ABPBI, the resulted composite was not melt-processible since the melting points (if there is one) of the two component polymers are well above 800 °C. Efforts were then put on systems with a thermoplastic polymer as the matrix. One such system was PBT/nylon 66 (Chuah et al, 1987). Thus, the PBT/nylon 66 in different ratio was dissolved in methane sulphonic acid to make 2 wt-%-3 wt-% (rapid coagulation into thin films. The films were optically clear and did not show gross phase separation in... [Pg.275]

Dichlorophenol and a little trifluoro-methan sulphonic acid weretreated with chlorine at 70C during 54 min. [Pg.230]

Raphael, the iodoaromatic (227) is first coupled with the acetylenic alcohol (228) in the presence of Pd° leading to the central intermediate (229). Meyer-Schuster rearrangement of (229) in the presence of methane sulphonic acid then gave rise to (231) presumably via the initially formed ketone (230). Reduction of (231) followed by dehydration next led to (232), which was elaborated to virantmycin, via epoxidation, reduction, deprotection, treatment with thionyl chloride, and finally ester hydrolysis. [Pg.654]

An alternative method is to use an ion chromatograph, where the sample is ashed for about 10 h at 750°C, the residue dissolved in HNO3, diluted with distilled water to a given volume and an aliquot eluted with 0.02% methane sulphonic acid (CH3SO3H), which forms the Na salt and the conductivity is then checked against known Na standards. [Pg.661]

Isolation of individual alkaloids or their mixtures from field ergot or fermentation broths, their hydrogenation, preparation of salts with methane sulphonic acid and adjustment to required ratio of individual components. [Pg.391]

Isolation ergocristine from ergot or fermentation broth, its hydrogenation and salt formation with methane sulphonic acid... [Pg.392]

This compound is not well known till now it was only mentioned in a patent C58). We managed to prepare it in an analogous way to compound /3/ in good yield (46). After careful purification, colourless crystals witH a melting point of 23,5°C are yielded (b.p. 51°C,lo 3 torr H-NMR CCDCI3) S = 4,70(s 2H) 3,73 (s 8H) 3,63 (s 8H). This cyclic formal is also readily polymerizable by several initiators (as e.g. boron trifluoride etherate, tin tetrachloride, trifluoroacetic acid etc.) (59). At the solution polymerization in methylene cHToride ( [mJ = 2-3 Mole/1) at 0 C with trifluoro-methane sulphonic acid (0,5 mole ) waxlike polymers are obtained (molecular weights 20,000 - 30,000), which are easily soluble in water and in organic solvents. [Pg.94]

The polymer is treated for 4 h at 80 C with l-fluoro,2,4-dinitrobenzene in an ethanol hydrogen carbonate medium. After washing out the excess of reagent, the dinitrophenyl group introduced is measured spectrophotometrically at 430 nm after dissolution of the derivatised polymer in methane sulphonic acid. [Pg.26]


See other pages where Methane sulphonate/sulphonic acid is mentioned: [Pg.498]    [Pg.179]    [Pg.129]    [Pg.147]    [Pg.102]    [Pg.369]    [Pg.51]    [Pg.198]    [Pg.147]    [Pg.126]    [Pg.278]    [Pg.369]    [Pg.139]    [Pg.65]    [Pg.57]    [Pg.265]    [Pg.255]    [Pg.278]    [Pg.340]    [Pg.585]    [Pg.111]    [Pg.463]    [Pg.353]    [Pg.413]    [Pg.595]    [Pg.618]    [Pg.245]    [Pg.107]   
See also in sourсe #XX -- [ Pg.266 , Pg.278 , Pg.278 ]




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