Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Self-drying

Self-calibrating, self-cleaning, and self-drying probe-type analyzer which simultaneously detects the concentrations of S02 and NO at temperatures up to 800°F. [Pg.376]

Barton et al. have described a particularly mild method for the conversion of ketoximes into ketimines (aldoximes give nitriles instead). A mixture of tributylphosphine and diphenyl disulfide reacts under anhydrous conditions with ketoximes, probably by way of the phosphorane intermediates shown in Scheme 20, to give ketimines. The reagent is effectively a self-drying one since it reacts irreversibly with water. Chlorodiphenylphosphine is also capable of deoxygenating ketoximes with this reagent... [Pg.392]

Water is likely to be present in aU practically relevant catalytic applications unless extreme precautions are taken or the system is self-drying (e.g., due to the fact that strong Lewis-acids or metal alkyls are used as co-catalysts). Water will influence the ionic liquid s thermal stability significantly if any part of the ionic liquid is prone to hydrolysis. Apart from the weU-known hydrolysis lability of tetrafluoroborates and hexafluorophosphates, water will thus also affect the stability of ester functionalities in the ionic liquid, e.g. the stability of alkyl sulfate anions. The presence of Bronsted acidity in the reaction system will further promote this kind of thermally induced hydrolysis reaction. Additionally, in strong Lewis-acidic ionic liquids care has to be taken to avoid incompatibilities between oxygen and nitrogen functionalities in the reactants or impurities and the ionic liquid s Lewis acidic group (usually a complex anion). It is for example obvious that the Pd-catalyzed dimerization of methylacrylate caimot be carried out in acidic chloroaluminate ionic hquids since the ionic liquid s anion would decompose in an irreversible reaction with the substrate methylacrylate. [Pg.450]

The cement content in deflocculated castables is low. Hence, the amount of heat they produce during setting is low. The time of installation can therefore be limited to 24 h. There are special ULCC castables, which are installed in blast furnace trough systems. They contain metallic additives and catalysts. Because of these, an intensive exothermal reaction takes place after the addition of water. Hydrogen is produced out of this reaction. It creates capillaries as it escapes from the structure. These capillaries help in the self-drying process because they increase the surface area from which heat is remov. Because of the fast reaction and drying, the furnace can be put into operation in a short time. [Pg.397]

Assemble the apparatus shown in Fig. 1 V, 67, 1 this is self-explanatory. The distilling flask has a capacity of 250 ml. and the beaker contains 150 ml. of 10 per cent, sodium hydroxide solution. All corks must fit well and should be coated with paraflSn wax (by dipping into molten wax, and allowing to drain). Place half of the yield of the dry phenyldiazonium fluoborate in the distilling flask. Heat the solid gently with a small luminous flame at one point near its surface until decomposition begins withdraw the flame and allow the reaction to continue... [Pg.610]

Poly(vinyl acetate) is used in latex water paints because of its weathering, quick-drying, recoat-ability, and self-priming properties. It is also used in hot-melt and solution adhesives. [Pg.1025]

Vanilla. Vanilla is the dried, cured, fuU-sized, but not fully ripe fmit pods (beans) of Vanillaplanifolia And. and V. tahitensis J. W. Moore (Orchidaceae). The vine is native to the tropical rain forests of southern Mexico, Central America, the West Indies, and northern South America. Plantings were started in Madagascar, Reunion, Java, Mauritius, and Zanzibar in 1840. The Madagascar-type bean is stUl the most important, but Indonesia produces more than Malagasy. The stmcture of the flower prevents self-pollination and therefore, where insects are not prevalent, hand pollination is necessary. [Pg.30]

Storage and Handling. Plutonium can be stored safely in dry air. Because of self-heating, storage accompanied by heat removal is advisable. The metal can be machined in moisture-free air containing at least 70 vol % Ar or He. Casting and foundry operations that requite melting of the metal must be carried out in vacuum or inert atmospheres and special containers. [Pg.196]

In dry air at room temperature this reaction is self-limiting, producing a highly impervious film of oxide ca 5 nm in thickness. The film provides both stabihty at ambient temperature and resistance to corrosion by seawater and other aqueous and chemical solutions. Thicker oxide films are formed at elevated temperatures and other conditions of exposure. Molten aluminum is also protected by an oxide film and oxidation of the Hquid proceeds very slowly in the absence of agitation. [Pg.94]


See other pages where Self-drying is mentioned: [Pg.238]    [Pg.337]    [Pg.337]    [Pg.339]    [Pg.348]    [Pg.35]    [Pg.304]    [Pg.238]    [Pg.337]    [Pg.337]    [Pg.339]    [Pg.348]    [Pg.35]    [Pg.304]    [Pg.466]    [Pg.2884]    [Pg.4]    [Pg.222]    [Pg.171]    [Pg.133]    [Pg.349]    [Pg.396]    [Pg.149]    [Pg.457]    [Pg.216]    [Pg.216]    [Pg.38]    [Pg.40]    [Pg.410]    [Pg.151]    [Pg.20]    [Pg.211]    [Pg.260]    [Pg.518]    [Pg.284]    [Pg.265]    [Pg.337]    [Pg.373]    [Pg.151]    [Pg.169]    [Pg.257]    [Pg.508]    [Pg.467]   
See also in sourсe #XX -- [ Pg.335 , Pg.338 , Pg.339 , Pg.340 , Pg.348 ]

See also in sourсe #XX -- [ Pg.86 , Pg.144 ]

See also in sourсe #XX -- [ Pg.21 , Pg.31 , Pg.111 , Pg.135 ]

See also in sourсe #XX -- [ Pg.3 , Pg.87 ]

See also in sourсe #XX -- [ Pg.80 ]




SEARCH



© 2024 chempedia.info