- Sensitized photolysis of stearic acid azide
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In an IR-spectroscopic study of the sensitized photolysis of stearic acid azide in a solution of benzene, it was found that the introduction of Michler's ketone into the system decreased the efficiency of isocyanate formation by a factor of about 10. It was hypothesized that the azide photolysis in the presence of Michler's ketone can be explained by the formation of a complex of the acyl azide with the ketone in a triplet excited state, a displacement of electron density from the acyl azide group, and its degradation with the formation of a triplet acylnitrene, which is incapable of rearranging into isocyanate.
- Budruev,Oleinik
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- Synthesis of carbamate-linked lipids for gene delivery
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Series of lipids 1a-d and 2a,b, with carbamate linkages between hydrocarbon chains and ammonium or tertiary amine head, which were pH sensitive, were synthesized for liposome-mediated gene delivery. The variable length of carbon chains and quaternary ammonium or neutral tertiary amine heads allowed to find the structure-function relationship of how these factors affect cationic lipids on gene delivery performance.
- Liu, Dongliang,Hu, Jianjun,Qiao, Weihong,Li, Zongshi,Zhang, Shubiao,Cheng, Lvbo
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- WATER-SOLUBLE POLYSACCHARIDE ETHERS AND THEIR USE
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The invention relates to modified polysaccharide ethers having a weight-averaged molecular weight of 40000 to 50000 g/mole, zero shear viscosity of more than 10 Pas, and pseudoplasticity of more than 20, obtainable by reacting cellulose-based polysaccharide ether(s) with at least one mesogenic modification agent or modified polysaccharide ethers, obtainable by reacting polysaccharide ether(s) selected from the group consisting of hydroxypropylmethyl cellulose (HPMC), hydroxyethylmethyl cellulose (HEMC), methyl cellulose, and cellulose ethers with methyl and/or ethyl and/or propyl groups and mixtures thereof, with at least one mesogenic modification agent. Said substances can be used to produce gel-like to stable aqueous preparations having viscoelastic flow properties, which are suited for use in the human body, particularly within the scope of ophthalmologic procedures.
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- Semicarbazides as gel forming agents for common solvents and liquid crystals
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This paper describes the synthesis of 14 new gelling agents with semicarbazide groups as H-bonding motifs and alkyl- and/or azobenzene side groups. They gel solvents like decaline, 1,2-dichlorobenzene and toluene and liquid crystalline mixtures. X-Ray structure analysis shows that the semicarbazides are connected by H-bonds, each molecule to four neighbours. As a result a ribbon is formed with a core of H-bonded semicarbazide groups and alkyl chains sticking to the side. IR measurements show an unchanged H-bonding motif in large crystals and in the gel fibres, even in LC-mixture. During heating the gel melts (rheology), while the H-bonding motif of the crystal disappears (IR and DSC measurements). First experiments show that these gel-forming agents can be used to gel LC-phases and to stabilise the director pattern present during gel formation. The Royal Society of Chemistry 2006.
- Deindoerfer, Pia,Geiger, Thomas,Schollmeyer, Dieter,Ye, Jian Hui,Zentel, Rudolf
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p. 351 - 358
(2007/10/03)
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- Phase change ink formulation
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Colored waxes are made by reacting selected nucleophiles, including alcohol containing colorants with an isocyanate are disclosed. A phase change ink is made by blending the colored wax with a clear ink carrier composition. The clear ink carrier composition can be a fatty amide-based material and/or a combination of isocyanate-derived resins in which the order ofaddition of the isocyanate and the different nucleophiles can tailor the distribution of di-urethane, mixed urethane/urea, and/or diurea molecules in the final resin product. The colored wax materials are useful as ingredients with phase change ink carrier compositions to make phase change ink jet inks.
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- CHIMIE DES SUCRES SANS GROUPEMENTS PROTECTEURS-II REACTIONS SELECTIVES D'ADDITION DU D-GLUCOSE, DU D-GALACTOSE ET DE D-GLYCOSYLAMINES A DES HETEROCUMULENES
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Alkyl isocyanates reacted with 1.5 equivalent of α-methylglucoside, glucose or galactose in pyridine at room temperature, and selectively gave the corresponding 6-N-alkylcarbamates in good yields.The readily available glucosylamine and lactosylamine (1.5-2 eq.) reacted with alkyl isocyanates and isothiocyanates in polar aprotic solvents (pyridine, NMP or DMF), thus affording good yields of the corresponding N-glycosyl N'-alkyl ureas and thioureas.These new sugar derivatives are non-ionic detergents.
- Plusquellec, Daniel,Roulleau, Fabienne,Lefeuvre, Martine,Brown, Eric
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p. 465 - 474
(2007/10/02)
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- Bicyclic amidines
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New amidine/isocyanate adducts are particularly useful as catalysts for hardening epoxy resins, in particular pulverulent coating compositions based on epoxy resins. New bicyclic amidines are excellent starting materials for manufacturing these amidine/isocyanate adducts.
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- Dispersion of aromatic isocyanatosulfonic acid uretdiones in organic polyisocyanates and a process for their preparation
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The instant invention is directed to non-sedimenting dispersions of finely divided solid aromatic isocyanatosulfonic acid uretdiones in non-sulfonic polyisocyanates and a process for their preparation.
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