- Preparation of amphiphilic sorbitan monoethers through hydrogenolysis of sorbitan acetals and evaluation as bio-based surfactants
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Amphiphilic sorbitan acetals have been prepared from sorbitan by acetalisation using linear aliphatic aldehydes or by transacetalisation starting from the corresponding aldehyde diethylacetals. A series of sorbitan acetals has been obtained with 29-81% isolated yields. It has been shown that these sorbitan acetals exist as a mixture of five-membered and six-membered regioisomers. Hydrogenolysis of the mixtures gave the corresponding sorbitan ethers as a mixture of 3 regioisomers with 55-85% isolated yields. A one-pot two-step procedure was also optimized from sorbitan giving similar results. The amphiphilic properties of sorbitan acetals and ethers were evaluated and both families exhibit interesting surfactant properties.
- Gozlan, Charlotte,Deruer, Elsa,Duclos, Marie-Christine,Molinier, Valérie,Aubry, Jean-Marie,Redl, Andreas,Duguet, Nicolas,Lemaire, Marc
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p. 1994 - 2004
(2016/04/19)
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- PRECIPITATION POLYMERIZATION IN THE PRESENCE OF GLYCERIN MONOSTEARATE
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A process for preparing a copolymer composition A) by free-radical copolymerization of a monomer composition comprising: a) acrylic acid, b) optionally at least one compound, different from a), having a free-radically polymerizable, α,β-ethylenically unsaturated double bond and at least one anionogenic and/or anionic group per molecule, c) at least one free-radically polymerizable crosslinking compound which comprises at least two α,β-ethylenically unsaturated double bonds per molecule. The process is performed by precipitation polymerization in the presence of an auxiliary composition H) comprising H1) glycerol monostearate, and H2) at least one compound with an HLB value in the range from 4 to 10, selected from water-insoluble natural waxes, nonionic emulsifiers and mixtures thereof.
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- Encapsulation of microparticles in teardrop shaped polymer capsules of cellular size
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Microparticles such as propagules of eukaryotic biocontrol agents are encapsulated in cellular-scale polymer capsules that have a diameter similar to normal eukaryotic cells in a range of about 10 μm to about 400 μm. The microparticles are encapsulated by adding a hydrophobic dispersion medium such as a mixture of chloroform and hexane or a mixture of corn oil and n-hexadecane having a specific gravity of about 1 and containing an emulsifier such as lecithin to an aqueous suspension of the microparticles and a polymer matrix precursor such as alginate, agitating vigorously to form a stable emulsion of microscopic globules containing a microparticle, and adding the emulsion to an aqueous solution containing a polymerizing agent such as calcium chloride to polymerize and precipitate the globules to form microparticles encapsulated in polymer matrix capsules that may be of a teardrop shape having a length of 40-200% longer than the diameter. Precipitation of the globules is regulated by substantially matching the Specific Gravity of the hydrophobic dispersion medium and the aqueous suspension. The microparticle may be a viable propagule of a weed pathogenic fungus to provide a herbicidal composition.
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- Phospholipid-and cholestrol-free aqueous composition for topical application to the skin
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Phospholipid- and cholesterol-free aqueous compositions for topical application to the skin contain a pharmaceutically active ingredient and a vector system of controlled and in-depth transport and release of the active ingredient through the skin. The vector system comprises at least one first non-ionic surfactant which forms vesicles upon dispersion in water and a lamellar phase upon concentrating the vesicles, and at least one second non-ionic hydrophilic surfactant. The ratios of the two non-ionic surfactants are such that the vector system comprises flexible vesicles.
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- N-alkyl-lactams as crystallization inhibitors
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In the spraying of an aqueous liquor comprising at least one of 1-(4-chlorophenyl)-4,4-dimethyl-3-(1,2,4-triazol-1-yl-methyl)-pentan-3-ol and 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)-butan-2-ol, the improvement which comprises including in the liquor an N-alkyl-lactam of the formula STR1 in which R represents alkyl having 8 to 18 carbon atoms and n represents the numbers 3, 4 or 5,
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