Poly , potassium

Rings Ha, b and c were found to polymerize in bulk with DMSO as an activator and various catalytic amounts of the anionic initiator, potassium poly(dimethylsiloxane)diolate (for polymerization of Ila and b, see (22)). The latter is well known as an efficient initiator of cyclosiloxane polymerization. Thus... 

A series of complexes (Chart 5) have been reported that comprise both a poly(pyrazolyl)borate ligand and an intramolecularly chelating, monoanionic coligand. These are typically obtained via halide displacement and dimer cleavage by the respective sodium or potassium poly(pyrazo-lyl)borate salt, a means by which 462—466,45 467—469,143 and 470 479144 145 were each prepared in good yield, while the related poly (pyrazolyl)methane complexes 480+— 483+ were isolated as their perchlorate salts in the presence of NaClO 145... 

SYNS POTASSIUM POLY(VINYL SULFATE) PVSK SULFURIC ACID, MONOETHENYL ESTER, HOMOPOLYMER, POTASSIUM SALT... 

Polymer-polymer complexation is generally detected via conductometric or potentiometric titrations. Colloid titration represents an inverse-system where a polymer with known characteristics, such as potassium poly (vinylalcohol-sulfate) or poly(diallyldimethylam-moniumchloride), are used to quantify the concentration of polycation or polyanion, hence relying on a 1 1 stoichiometry. Using the cationic dye, tol-uidine blue, as an indicator, a metachromatic end point is detected. Both methods are volumetric. 

The above cyanide, whilst it yields a hydrosulphide with hydrogen sulphide, is also capable of yielding sulphides with potassium poly-... 

Stability of different strong polyelectrolyte/counterion mixtures is reported in this section sodium poly(vinyl sulfonate), potassium poly(vinyl sulfate), and sodium dextran sulfate. These polyelectrolytes have practically the same charge density. Poly(vinyl sulfonate) (NaPVS) and NaPSS possess the same charged groups (SOD but they differ by their backbones NaPVS is more... 

FIG. 1 Turbidimetric titration curves (so-called colloid titration) of different papain solutions with a solution of potassium poly(vinylsulfate) at 2.5 mmol/L. The volume of titrant at the abrupt increase of turbidity (V, ) is given in the figure. At the point of incipient precipitation, the polymer/protein ratio is constant. (Reprinted with permission from Ref. 27. Copyright 1996 American Chemical Society.)... 

Kokufuta E., Takahashi K. Stoichiometric complexation of bovine trypsin with potassium poly(vinyl alcohol sulphate) and enzymatic activity of the complex. Polymer 1990 31 1177-1182. 

Cha H. J., Izumi T., Kokufuta E., Franck C. W. Spectroscopic studies of papain complexation with potassium poly(vinyl alcohol sulphate) ACS Polym. Preprints 1992 33 872-873. 

Potassium poly (vinyl alcohol) sulfate (PVSK) was standardized against 2.5 X 10" N cetylpyridinium chloride monohydrate. A 1-mL ahquot of a 200-600-ppm copolymer solution was combined with 1 drop of toluidine blue indicator and agitated with a magnetic stirrer. PVSK was added dropwise until the endpoint was reached. Each titration was repeated a minimum of four times. 

In turbidimetric titration, a polyelectrolyte is added incrementally to another highly dilute polyelectrolyte solution and the intensity of the light scattered by or the turbidity due to complex or precipitate formation is measured. In this colloid titration, turbidity is recorded as a function of titrant volume and the end point indicated by maximum turbidity is used to ascertain the stoichiometry of complex formation as shown in Figure 56.5. Jiang and Zhu" used colloid titration to investigate PAA-gelatin complexation and Tsuboi et al." used it to study complexation of papain with potassium poly(vinylsulfonate) (KPVS). 

AQS = Anthraquinone-2-sulfonic acid M(TPS) = metal tetrasulfophthalocyanine BPS = bathephenanthroline disulfonic acid M(TPPS) = metal tetra(4-sulfophenyl)porphyrin PVSK = potassium poly(vinylsulfate) PSSNa = sodium poly(styrene sulfonate) Nafion = Salt of sulfonated and Wghly fluorinated polymer (trademark of Du Pont). 

Anionic polyelectrolytes (PE), such as potassium poly-(vinyl-sulphate) (PVSK), (sodium poly(styrene-4-sulphonate) (PSSNa) and Nafion, were incorporated in conducting polymer according to the same procedure as described above, and charge-controllable conducting polymer membranes were obtained [15-17]. 

Figure 2038. Lamella spacing of potassium poly 3-(3-alkylp5rrrol-l-yl)propanesulfonates as a fimction of the 3-alkyl chain length. (Reprinted by permission of ref. 31)...

A procedure leading to a water-soluble, powdery potassium poly(acrylate) is given in Preparation 2-2 [17]. 

Graft polystyrene/poly(ethylene oxide), poly(styrene-g-ethylene oxide) (174), has been prepared by making chloromethylated polystyrene and condensing this product with living potassium-poly(ethylene oxide). The chloromethylpolystyrene can be prepared by chloromethylating polystyrene (175) or by copolymerization. 

Employing type III turbidimetric titration (in which PE is added to protein at constant pH and ionic strength), Kokufuta [9, 20] studied complexation between human serum albumin (HSA) and PDMDAAC and potassium poly(vinyl alcohol sulfate) (KPVS). He found a turbidimetric end point at which the mole numbers of quaternary ammonium groups in PDMDAAC and sulfate groups in KPVS are approximately identical, respectively, to the contents of the acidic and basic groups in HSA. Therefore, the complexation between HSA and PDMDAAC and KPVS was described as stoichiometric. A similar result was also found in the BSA-PDMDAAC system [21]. 

In recent fluorescence studies of papain complexation with potassium poly(vinyl alcohol sulfate) (KPVS), Frank et al. [29, 30] found a blue shift in the emission spectra of papain in the presence of KPVS, as shown in Fig. 15.8. These blue shifts were interpreted as the result of shielding of tryptophan residues from aqueous media by the complexed KPVS chains. It was suggested that Classes II (Trp 69) and III (Try 7, 177, and 181) tryptophans are initially exposed to the aqueous environment, but subsequently bind with KPVS. At increased papain concentration, the shielding effect was found to decrease (see Fig. 15.9). Thus, a high degree of complexation at low papain content was suggested. 

KPVS potassium poly(vinyl alcohol sulfate)... 

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