Polystyrenes soluble dyes

Polymer-soluble dyes of very different chemical constitutions were developed for the coloration of polystyrene and other transparent plastics. These dyeings... 

These dyes have affinity for one or, usually, more types of hydrophobic fibre and they are normally applied by exhaustion from fine aqueous dispersion. Although pure disperse dyes have extremely low solubility in cold water, such dyes nevertheless do dissolve to a limited extent in aqueous surfactant solutions at typical dyeing temperatures. The fibre is believed to sorb dye from this dilute aqueous solution phase, which is continuously replenished by rapid dissolution of particles from suspension. Alternatively, hydrophobic fibres can absorb disperse dyes from the vapour phase. This mechanism is the basis of many continuous dyeing and printing methods of application of these dyes. The requirements and limitations of disperse dyes on cellulose acetate, triacetate, polyester, nylon and other synthetic fibres will be discussed more fully in Chapter 3. Similar products have been employed in the surface coloration of certain thermoplastics, including cellulose acetate, poly(methyl methacrylate) and polystyrene. 

It was our intention when this new work began to outline, more fully, the effect of the polymeric structure on the effectiveness of rose bengal as a photosensitizer and to compare the behavior of the polymer-bound dye to the behavior of the dye - free - in solution. In the present paper, therefore, we report on the photochemical and spectral properties of new singlet oxygen sensitizers based on soluble polystyrenes. These new derivatives are referred to as P -RB. 

Solvent dyes [1] cannot be classified according to a specific chemical type of dyes. Solvent dyes can be found among the azo, disperse, anthraquinone, metal-complex, cationic, and phthalocyanine dyes. The only common characteristic is a chemical structure devoid of sulfonic and carboxylic groups, except for cationic dyes as salts with an organic base as anion. Solvent dyes are basically insoluble in water, but soluble in the different types of solvents. Organic dye salts represent an important type of solvent dyes. Solvent dyes also function as dyes for certain polymers, such as polyacrylonitrile, polystyrene, polymethacrylates, and polyester, in which they are soluble. Polyester dyes are principally disperse dyes (see Section 3.2). 

Self quenching of excited state dye by ground state dye with rose bengals immobilized to soluble polystyrenes occurs, but it is not observed with the beads. 

The size of obtained microcapsules is defined by the one of colloid microparticles (cores) and can be in an interval from several tens nanometers up to tens micrometers. A wide variety of colloid microparticles of organic and inorganic nature can be used as soluble cores for reception of microcapsules. There are microparticles based on melamine formaldehyde polymers and polystyrene latex, crystals of organic dyes, particles based on inorganic compounds such as metal carbonates Si02, protein aggregates, cellular constructions. ... 

Apparently, because of the (necessarily) poor solubility of the dye in the organic solvent, the dye-endgroup ion-pair must be formed in the water-solvent interface. Because of the apolar nature of polystyrene, few endgroups actually come to this interface and, therefore, the ion-pair formation is not quantitative. As the polymer-polymer interaction increases at higher concentrations, the extent of ion-pair formation decreases. This explanation was confirmed recently by experiments of Huber and Thies (13) on the adsorption of toluene-soluble polymers at the toluene-water interface. They conclude that polystyrene has little affinity for this interface but that poly(methyl methacrylate) adsorbs significantly... 

Roth et al. [42] used steady-state fluorescence measurements to study the emission spectra of pyrene and anthracene dyes covalently bonded to polystyrene (PS) upon phase separation from poly(vinyl methyl ether) (PVME). The total fluorescent dye content in the samples was <0.02 mol%. As shown in Figure 25.15a, before phase separation the fluorescence intensity of the spectra decreased slowly with increasing temperature. However, after phase separation (see Figure 25.15b) a sharp increase in fluorescence intensity was observed, which was attributed to the removal of fluorescence quenching of the dye by the local presence of the more polar PVME component in the misdble state. These results showed clearly that the PS/PVME blend displays a lower critical solubility temperature (LCST) type of phase diagram. 

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