The effect of hydrogen bonding addends on the dilute solution viscosity of poly(acrylamide) and unionized poly(acrylic acid) and poly(methacrylic acid)

Eliassaf, Jehudah; Silberberg, A.

doi:10.1002/pol.1959.1204113804

Cited by 58 publications

(14 citation statements)

References 15 publications

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“…In addition the intrinsic viscosities of the aqueous acid solutions of PMA and P AA are changed in quite a different manner when different substances are added to the solutions. 21,24 From our point of view all these results could be explained by the assumption that the local compact structures in the PMA molecules are stabilized to a much greater degree by hydrophobic interactions of methyl groups than by intramolecular hydrogen bonds. Hydrophobic interactions are known to be of entropic and not of energetic origin;25,26 therefore they become stronger with increasing temperature.…”

Section: Hydrophobic Interactions In Pma Moleculesmentioning

confidence: 85%

The models of the denaturation of globular proteins. II. Hydrophobic interactions and conformational transition in polymethacrylic acid

Ануфриева

Birshtein

Некрасова

et al. 1967

J. polym. sci., C Polym. symp.

105

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SynopsisTo model the compact structures of globular proteins and the processes of their breakdown, the local compact structures have been investigated in the nonionized (or weakly ionized) molecules of polymethacrylic acid (PMA) in aqueous solutions. The potentiometric titration curves differ markedly from the analogous curves for polyacrylic acid (PAA) and show the existence of the cooperative breakdown of the local compact structures in a definite region of the ionization degree. The presence of the local compact structures in the PMA molecules is also manifested in sharp differences between the luminescent characteristics of the dyes (auramine and acridine orange) in aqueous solutions with PMA and the same characteristics in aqueous solutions with PAA. In a certain range (which coincides with the interval of the breakdown of local compact structures) these differences disappear. This permits us to interpret them as the result of the dye molecules binding on the structurized parts of PMA. The assumption has been made that the local compact structures in the PMA molecules in aqueous solutions are stabilized by the hydrophobic interactions of methyl groups. This assumption explains the abnormal temperature dependencies of the properties of the aqueous solutions of PMA and the absence of the local compact structures in the PMA molecules in methanol as well as in the P AA molecules in any solvents. To check this assumption we have. investigated the breakdown of the local compact structures in the PMA molecules when aliphatic alcohols are added to the aqueous PMA solution. It was shown that the transition of dye molecules from the bound state to the free one (which is the evidence of the breakdown of the local compact structures) takes place in the narrow range of alcohol concentrations decreasing in the series methanol-ethanol-propanol-butanol. It means that alcohol destroys compact structures the better, the more hydrophobic groups it possesses.The investigations of intrinsic viscosity of PMA in the water-methanol mixtures have shown that the addition of alcohol leads not only to the breakdown of the local compact structures, but also the unfolding of the macromolecule as a whole. The analogy between the local compact structures in PMA molecules and the compact structures of globular proteins has been discussed.

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Section: Hydrophobic Interactions In Pma Moleculesmentioning

confidence: 85%

The models of the denaturation of globular proteins. II. Hydrophobic interactions and conformational transition in polymethacrylic acid

Ануфриева

Birshtein

Некрасова

et al. 1967

J. polym. sci., C Polym. symp.

105

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“…J., Vol. 32 ing the initial shear rate (Figure 4), however, indicate that there is a competitive construction and destruction of the structure in the solution. Thus the lower the initial shear rate, the more the structure is constructed and survived, and the resultant higher viscosity makes the rate of shear still lower, or vice versa.…”

Section: Discussionmentioning

confidence: 98%

Shear-Induced Viscosity Change of Aqueous Polymethacrylic Acid Solution

Ohoya

Hashiya

Tsubakiyama

et al. 2000

Polym J

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Rheopectic behavior of the aqueous polymethacrylic acid (PMA) solution was investigated with a Zimm-Crothers type viscometer. Measurements were performed for the solutions of PMA ranging in molecular weight from 6 X 10 5 to 16 X 10 5 , at concentration of 0.05-5.0 wt% and shear rate of 0.5-7 .0 s -1 . The solution viscosities of high molecular weight PMA (Mv > lOX 10 5 ) increase linearly with the elapse of shearing time at early stage, reach a maximum and then fall off. Ratio of the maximum viscosity to the initial one, llmaJllinit, decreases with decreasing the concentration of polymer and increasing the rate of shear, indicating that rheopexy is attributed to a competition between growth and disruption of the molecular clusters in the shear field. The influences of four additives (HCl, NaOH, NaCl, and urea) on rheopexy were examined ; it was found that, regardless of the additive species, there is a correlation between rheopexy and the initial rate of shear. These results suggest that a particular balance of hydrophilic and hydrophobic bonding abilities of PMA molecule is essential for the occurrence ofrheopexy in the solution.

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“…The addition of salt to hydrosoluble polymers can produce a change in the solubility properties, known as "salting out", which originates from the strong interactions of ions with water [24]. However, PAM has been previously shown to be unaffected by salt addition in aqueous solution [8]. Indeed, the exponent a of the Mark-Houwink relationship between intrinsic viscosity [1/] and molecular weight M:…”

Section: =Ai(oh)~ Oh---aiohmentioning

confidence: 99%

“…The basic idea was as follows: electrolytes (alkaline chlorides) do not modify the conformational properties of polyacrylamide in aqueous solution, nor the thermodynamic affinity of acrylamide residues for water molecules (in the sense of the parameter Z of Flory) [8,9]. However, on account of the charged nature of the edge faces, the presence of sak strongly affects their physico-chemical properties [10,11].…”

Section: Introductionmentioning

confidence: 99%

Polyacrylamide Na-kaolinite interactions: Effect of electrolyte concentration on polymer adsorption

Pefferkorn

Nabzar

Varoqui

1987

Colloid & Polymer Sci

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Abstract:The variation in polyacrylamide adsorption on Na-kaolinite as a function of the electrolyte concentration of the clay suspension, was determined under three pH conditions, where the clays display varying charge characteristics. Interpretation of the results is based on two arguments: non-charged polyacrylamide adsorption is restricted to the edge faces of the colloidal platelets and hydrogen bonding between the amide groups of the polymer and the "isolated" hydroxyl sites of these faces is the mode of surface attachment. At constant pH, when Na-kaolinite bears charged surface groups, the polymer adsorption, which is related to the density of the anchoring sites, parallels the state of ionization of the edge surface. The mechanism by which the salt modifies the adsorption properties of the kaofinite in neutral medium is not established with certainty. Nevertheless, no polymer-clay association occurs if the surface is entirely uncharged. This result is in line with the fact that while hydroxyl groups are engaged in internal hydrogen bonds, they cannot hydrogen-bond to the polyacrylamide. Variations in the clay-polymer affinity are attributed to a modification of the interfacial structure of the adsorbed polymer, associated with changes in the surface density of the anchoring groups.

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The effect of hydrogen bonding addends on the dilute solution viscosity of poly(acrylamide) and unionized poly(acrylic acid) and poly(methacrylic acid)

Cited by 58 publications

References 15 publications

The models of the denaturation of globular proteins. II. Hydrophobic interactions and conformational transition in polymethacrylic acid

The models of the denaturation of globular proteins. II. Hydrophobic interactions and conformational transition in polymethacrylic acid

Shear-Induced Viscosity Change of Aqueous Polymethacrylic Acid Solution

Polyacrylamide Na-kaolinite interactions: Effect of electrolyte concentration on polymer adsorption

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