Polymeric dyes precipitant

The polyesters or polyurethanes were dissolved in halogenated solvents like chloroform, chlorobenzene or 1,2-dichioroethane and to the solutions were added equivalent amounts of the appropriate diarylketones and phosphorous oxychloride. The mixtures were heated to reflux for several.hours and the solvents were thereafter removed under reduced pressurs. The highly colored solids were purified by precipitation from N-methyl pyrrolidone solutions into acetone. They were filtered, washed and dried under a vacuum. The visible spectra of the polymeric dyes were measured in methanol solutions. 

In some cases, dye-forming moieties attached to a polymeric backbone, called a polymeric coupler, can replace the monomeric coupler in coupler solvent (51). In other reports, very small particles of coupler solubilized by surfactant micelles can be formed through a catastrophic precipitation process (58). Both approaches can eliminate the need for mechanical manipulation of the coupler phase. 

Fig. 4 Schematic representation of the techniques used for making stained beads (a) staining during polymerization (b) staining via covalent or electrostatic coupling of an indicator to the beads surface (c) staining via swelling (d) preparation of dye-doped beads via precipitation (e) spray-drying (f), grinding...

Polymeric beads obtained via emulsion polymerization, precipitation, etc. can be stained with dyes providing that both have functional groups available [7]. Covalent coupling is mostly preferred but the attachment based on strong electrostatic interactions is also feasible. This method is mostly used to design pH- and ion-sensitive micro- and nanobeads. The dynamic response of such systems can be... 

USE To make other zirconium compds to precipitate acid dyes to prepare high quality pigment toners to improve the properties of color lakes. Aq ZrOCl, solns have considerable solvent action on sparingly sol sulfates, such as calcium sulfate. The Free acid in ZrOCl2 solns may be neutralized, and a sol compd ZrOOHCl-xHjO can be recovered. It is highly polymerized in soln and amorphous in the solid state has been used in the prepn of body deodorants and antiper-spirant preparations. 

Each of the products whose synthesis is illustrated in Schemes 6.2 and 6.3 is a coloured cationic species. When the counteranion is chloride, the products are water-soluble and useful as basic (cationic) dyes for the eoloration of acrylic fibres. Precipitation of cationic dyes of these types from aqueous solution using large polymeric counteranions, notably phosphomolybdates, phosphotungstates and phos-phomolybdotungstates, leads to a range of highly insoluble red. 

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