The interaction of poly(vinyl pyrrolidone) with cosolutes

Abstract

The interaction of poly(vinyl pyrrolidone) with a series of cosolutes has been studied by means of viscosity, solubility, dialysis, and electrophoresis methods. The cosolutes comprise a number of mono‐ and divalent acids and their salts, and most of the natural amino acids. It is found that appreciable interaction occurs with divalent acids and salts, with hydroxy acids, aromatic acids, and with amino acids which possess either aromatic or other ring structures. The interactions are probably related to a saltingout process, and a qualitative mechanism is suggested which accounts for the observed charge and specific effects in terms of dielectric attraction and repulsion between the cosolute anion and the pattern of polar and nonpolar sections of the PVP molecule.

Structure of Polyvinylpyrrolidone-Iodine (Povidone-Iodine)

“…The structure of povidone-iodine USP XIX prepared by heating p~lyvinylpyrrolidone~ with iodine agrees with that of a product obtained by the direct synthesis of p~lyvinylpyrrolidone~, hydrogen iodide, and iodine. Previous assumptions regarding the structure of polyvinylpyrrolidone-iodine (18)(19)(20) are not consistent with the results discussed in this paper.…”

“…The influence of the iodide ion on iodine bonding to polyvinylpyrrolidone in chloroform and water waa investigated (11-17). Molecular iodine was bonded to polyvinytpyrrolidone in chloroform (18). In aqueous solution in the presence of potassium iodide, the polymer-bonded species was triiodide, with the potassium ion complexed directly so that an insoluble product was precipitated from solution.…”

Salt effect on polymer solutions

“…Compared with the accumulation of data of salt effect on small nonionic substances,"12 studies on nonionic macromolecules are rather rare. [13][14][15][16] The purpose of this report is to investigate effects of inorganic and organic salts, including surface-active long-chain salts, on solutions of these copolymers in relation to specific properties of the individual ions in water. The interactions of polymers and ionic surfactants have been discussed in detail elsewhere.17…”

Hydrophobic bonding in vinyl polymers

“…The fact that poly(methacry1ic acid) i s a weaker acid than poly(acry1ic acid) can be explained by the assumption of the existence of hydrophobic bonding in the former (6,7). The opposite response of the polyacids to the addition of ethanol and acetic acid (8) can be due to the fact that these two addends can form (besides hydrogen bonds) hydrophobic bonds with poly(methacry1ic acid), just a s with polystyrene (9), but only hydrogen bonds with poly(acry1ic acid). caproic acid on poly(methacry1ic acid) (8) is most likely due to hydrophobic bonding, just a s in the case of polystyrene (9).…”

“…Hence the binding of aromatic amino acids to this polymer (12) is probably of the same nature; the hydrophobic binding of aromatic amino acids to polystyrene has been observed (13). If the binding of benzoic acid (12) and sodium dodecyl sulfate (14) to both poly(acry1ic acid) and poly(methacry1ic acid) is ascribed to hydrophobic bonding, it must be concluded that the backbone of vinyl polymers can enter hydrophobic bonding if the size and the concentration of the addend are large enough.…”