Water-soluble polymerization

Amidation. Heating of the diammonium salt or reaction of the dimethyl ester with concentrated ammonium hydroxide gives adipamide [628-94-4] mp 228°C, which is relatively insoluble in cold water. Substituted amides are readily formed when amines are used. The most industrially significant reaction of adipic acid is its reaction with diamines, specifically 1,6-hexanediamine. A water-soluble polymeric salt is formed initially upon mixing solutions of the two materials then hea ting with removal of water produces the polyamide, nylon-6,6. This reaction has been studied extensively, and the hterature contains hundreds of references to it and to polyamide product properties (31). 

Emulsion Polymerization. Emulsion polymerization takes place in a soap micelle where a small amount of monomer dissolves in the micelle. The initiator is water-soluble. Polymerization takes place when the radical enters the monomer-swollen micelle (91,92). Additional monomer is supphed by diffusion through the water phase. Termination takes place in the growing micelle by the usual radical-radical interactions. A theory for tme emulsion polymerization postulates that the rate is proportional to the number of particles [N. N depends on the 0.6 power of the soap concentration [S] and the 0.4 power of initiator concentration [i] the average number of radicals per particle is 0.5 (93). 

In secondary operations, where chemicals are injected into hydrocarbon formations in conjunction with a chemical flooding process, polyamines are used to reduce the loss of injected chemicals to the formation by adsorption and precipitation (312). TEPA and other ethyleneamines are used with water-soluble polymeric thickeners in water—flood petroleum recovery operations to stabilize viscosity, mobiUty, and pH while imparting resistance to hydrolysis (313). 

A reliable chromatographic method has been developed for the quantitative aneilysis of hydrophobic impurities in water-soluble polymeric dyes. The method utilizes both the molecular sieve effect of normal gel permeation chromatography and solute-column packing interaction, modified by solvent composition. This method eliminates the need to extract the impurities from the polymeric dye with 100 extraction efficiency, as would be required for an ordinary liquid chromatographic analysis. 

Water-soluble polymeric dyes have been prepared from water-insoluble chromophores, viz., anthraquinone derivatives. Unreacted chromophore and its simple derivatives, which are all water-insoluble, remain in solution due to solubilization by the polymeric dye. A method has been developed to separate and quantitate the polymeric dye and these hydrophobic impurities using Sephadex column packing. The solvent developed has the property of debinding the impiirities from the polymer, and further allows a separation of the imp irities into discrete species. This latter separation is based on the functional groups on the impurity molecules, having a different interaction with the Sephadex surface in the presence of this solvent. The polymer elutes at the void volume... 

The immobilization of metal nanoparticles with a water-soluble polymeric material such as PVP has also been described. The groups of Choukroun and Chaudret have described the hydrogenation of benzene in a biphasic mixture with PVP-protected native Rh nanoparticles synthesized from the organometal-... 

Oligosaccharide syntheses employing enzymatic reactions would in principle greatly benefit from being performed on a polymer support since the support might effectively facilitate isolation of the final product. Presumably, a water-soluble polymeric support will be preferable to any insoluble support since reaction rates could otherwise become too slow. Glycosidases as synthetic enzymes would be the best candidates to study this type of the enzymic approach to oligosaccharide synthesis. 

Nishimura and Yamada [10-11] introduced a water-soluble polymeric support having a linker recognized by ceramide glycanase for a synthesis of ganghoside GM3 (17). Synthesis of the polymerizable lactose derivative (14) with a ceramide glycanase sensitive linker is shown in Scheme 10.3. The lactosyl ceramide (Lac-Ger) mimetic glycopolymer (15) is obtained from the monomeric precursor (14) by co-polymerization with acrylamide. 

Water soluble polymeric ligands in aqueous hydroformylation... 

Not surprisingly, the use of acidified water increased the level of fluoride release from the glass, and this effectively models what happens in a setting cement. The acid-base reaction between the glass and the water-soluble polymeric acid liberates fluoride from the glass, causing it to move to the matrix, from where it is gradually leached as the cement releases fluoride [227,228]. 

The conversion of dextran with 1,2-epoxy-3-phenoxypropane, epoxyoctane or epoxydodecane may be exploited for the preparation of amphiphilic dextran derivatives. Polymeric surfactants prepared by hydrophobic modification of polysaccharides have been widely studied, starting with the pioneering work of Landoll [261]. Neutral water-soluble polymeric surfactants can be obtained by reaction of dextran with 1,2-epoxy-3-phenoxypropane in 1 M aqueous NaOH at ambient temperature (Fig. 35, [229,233]). The number n of hydrophobic groups per 100 Glcp units varies between 7 and 22 depending on the reaction conditions. 2-Hydroxy-3-phenoxy propyl dextran ethers (DexP) behave like classical associative polymers in aqueous solution. In dilute solution, the intrinsic viscosity decreases significantly whereas... 

A number of water-soluble polymeric radic rotective ents have been prepamd by... 

Charvalos E, Tzatzarakis M, Tsatsakis A, Petrikkos G. Controlled release of water-soluble polymeric complexes of sorbic acid with antifungal activities. Appl Microbiol Biotechnol 2001 57(5-6) 770-775. 

The reagent layer comprises all the components required for completing the reaction. It is uniformly coated on the support base, to which it is affixed by a water-soluble polymeric binder. The sample extends uniformly over the reagents, thus enabling the reaction to take place. The chemicals within the reagent layer vary with the analyte being measured. The support base material is a polyester film, of the same type as the films used for photography, with a smooth and uniform surface. 

Kopecek J. The potential of water-soluble polymeric carriers in targeted and site-specific drag delivery. J Control Release 1990 11 279-290. 

A noted earlier, coordination of transition-metal ions to water-soluble polymers can allow for facile catalyst recovery, by ultrafiltration, from water-soluble substrates and/or products. For example, Han and Janda [22] used an osmium complex of the water-soluble polymeric chiral ligand 8 as a catalyst for the asymmetric dihydroxylation of alkenes in aqueous acetone (Eq. 5). However, they suggested that the catalyst should be recovered by precipitation with methylene chloride. Obviously the use of an ultrafiltration membrane for catalyst separation would be far more attractive. nu... 

A variant on this theme is to attach a transition-metal complex of a smart polymer, the solubility of which can be dramatically influenced by a change in a physical parameter, e.g., temperature [23] (cf. Sections 4.6 and 4.7). Catalyst recovery can be achieved by simply lowering or raising the temperature. For example, block copolymers of ethylene oxide and propene oxide show an inverse dependence of solubility on temperature in water [24]. Karakhanov et al. [25] prepared water-soluble polymeric ligands comprising bipyridyl (bipy) or acetylacetonate (acac) moieties covalently attached to poly(ethylene glycol)s (PEGs) or ethylene oxide/propene oxide block copolymers 9 and 10. 

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