Polysalts

In solutions, the counterions of poly electrolytes are HjO (for the polyacids) and OH (for the polybases), cations such as K+ and Na, or anions such as Cl (for the polysalts). The addition of polyvalent counterions (such as Ca, Mg, Cu, AT ) produces ionic cross-linking interfering with solubility The polyelectrolyte precipitates and may be redissolved upon addition of a strong acid (such as HCl). This can be regarded as a special case of ion exchange. 

Note A polyelectrolyte complex is also called a polysalt. Use of this term is not recommended. 

T0 prepare models of TA, the corresponding cyclic alkylene phosphoric acids cannot be directly polymerized because the presence of acidic protons of the phosphate group makes the ionic polymerization impossible. Thus, cyclic phosphorus compounds with blocked third functions have to be used. These are phosphates., phosphoramidates and phosphites. After polymerization the obtained polymer is converted by deblocking into the polyalkylene phosphate, e.g. polysalt or polyacid form. 

Treatment of 72 with methanolic ammonia yielded ammonium polysalt 73 with free hydroxyl groups. 

A kind of colloidal electrolyte consisting of a macromolecule that, when dissolved, dissociates to yield a polyionic parent macromolecule and its corresponding counterions. Also termed polyion , polycation , or polyanion . Similarly, a polyelectrolyte can be referred to in certain circumstances as a polyacid , polybase , polysalt , or polyampholyte (Ref. [978]). Example carboxymethylcel-lulose. 

Plum pudding resins are prepared from micro-bead particles of commercial resins, De-Acidite (1-10 pm) and Zeo-Karb 226 (5-10 pm) and a variety of polymers such as cellulosics, ionically crosslinked polysalts, or poly(vinyl alcohol) cross-... 

F. 8. Rate of salt uptake from 0.02 N salt solution by thermally r nerable plum pudding resins containing the same De-Acidite G and Zeo-K.arb 226 plums, and 30% matrix by weight, as a function of the nature of matrix. Particle size 14-52 mesh, BSS, base resin to acid resin ratio 2 5. (1) ethyl cellulose (2) polysalt (3) crosslinked poly (vinyl alcohol) (4) normal De-Acidite G and Zeo-I b 226 mixed bed... 

Table 8. The influence of the amount and type of polysalt matrix on the rate of salt uptake by thermally regenerable plum pudding resins...

Alginate-poly(L-lysine) and alginate-chitosan are, by far, the most common polymer-polymer coacer-vation systems, with the former often pregelled, in bead form, with divalent cations such as calcium or barium. As Table 2 indicates, polysaccharides with a rigid structure are generally favored for polysalt formation. 

Polysalts have been prepared as microcapsules for enzyme entrapment (biocatalysts), in the separation of proteins as well as in surfactant binding. Protein separation is particularly selective, with biomacromolecules separated according to their isoelectric point. Coaeervation is the preferred method for water soluble drugs where no modification of the absorption kinetics are warranted. 

Various combinations of the above are possible, for instance polyblends of materials from groups 2 and 3 or of a polycationic and a polyanionic material both from group 3. A special example of the latter is a stoichiometric blend of poly (sodium styrene sulfonate) and poly (vinylbenzyltrimethylammonium chloride) known as "polysalt which was recently studied by Gray (36). 

FIG. 4 Conductance in reaction mixtures and control solutions during complex formation between the polysalts NaPSS and PVBTAC1. (a) [NaSS] = [VBTAC1] = 10 3 N in salt-free solution, (b) [NaSS] = [VBTAC1] = 10 2 N in 10 2 N NaCl. (From Ref. 3b.)... 

Dautzenberg H, Linow KJ, Rother G. The formation of water-soluble polysalts. 6. Investigation of the stoichiometry of simplexes and of the preferential bonding from polymer mixtures. Acta Polymerica 1990 41(2) 98—102. 

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