The Concentration Dependence of the Viscosity of Solutions of Macromolecules

Riseman, Jacob; Ullman, Robert

doi:10.1063/1.1748295

Cited by 76 publications

(26 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This value has since been confirmed independently b~r other author [16]. It should also be m entioned that, using a different m ethod of attack, a differen t value of k (~) , namely, OA, h as b een derived [18,19] .…”

Section: Discussionmentioning

confidence: 55%

Viscosity of dilute and moderately concentrated polymer solutions

Weissberg¹,

Simha²,

Rothman³

1951

J. RES. NATL. BUR. STAN.

172

View full text Add to dashboard Cite

The viscosit ies of solut ions of t hree polysty rene fractions in t hree solve nts of v ar y ing solvent power were m easured at t wo temperat ures. The relat ive vi scosit ies of the syst em s investigated ranged from 1.03 to 43.The appli cability of two empirical expressions for the concen tration depende nce, nam ely t he Martin equation and t he Baker relation, is examined . In addit ion, t he results are represented by m eans of poly nomials of suitable degr ee. The numerical procedures for t he e valuatio n of t he coeffi cien ts are discussed in detail. In t he concent ration r an ge investigated , t he in troduction of a reduced co ncen t rat ion scale S = ['1] c, places t he viscosity-con cen t ration curves for different molec ular weights in t he same solven t on a more nearly common scale. This scale, S, is simply rela ted t o another reduced scale c/co. H ere Co represen ts t he concentration a t which t he equivalent spher es of t he coiling m olec ul es, a s d efin ed at infinite dilu tion, would just begin to o verlap . At c/co « 1, t he con cent ration dependence can be described in terms of hydrody namic in teract ion. This intera ction involves single molecul es and can also involve t he int rinsic v iscosity and interactions of aggregates of low order . An a ttempt is made t o d educe from t he viscosi ty data and on t he basis of cer tain hydrody namic results, t he equilibrium constant s and relative p opulations of s uch aggregates. R easonable values are obt ained . On approaching Co, t he a verage volume a vailable t o a chain molec ule in a good solve nt is redu ced because of t he cage form ed by its nearest neighbors. The effective press ure is just t he internal osmo tic press ure. This leads to an expression for t he concent rat ion depe ndence of t he viscosi ty, in terms of t he vi rial coeffi cie nts of osmotic press ure, luolec ular weight, and size. These equat ions are s hown to be in satisfactory agreemen t wi t h t he experimen tal data. In part icul ar , in t he neighborhood of Co one obtains r easo nabl e values for t he molec ular exte nsio n f actors of t he chain .

show abstract

Section: Discussionmentioning

confidence: 55%

Viscosity of dilute and moderately concentrated polymer solutions

Weissberg¹,

Simha²,

Rothman³

1951

J. RES. NATL. BUR. STAN.

172

View full text Add to dashboard Cite

show abstract

“…Somewhat larger Huggins' constants of 0.7 or higher are found for polymers in solvents approaching the theta point. According to Riseman and Ullman, k H should be 0.6 for random coils and 0.733 for rods in solution [13]. In the case of better solvents, observed k H values on the order of 0.25-0.35 are typical [3,7].…”

Section: Discussionmentioning

confidence: 97%

Anomalous dilute solution properties of segmented polydimethylsiloxane–polyurea copolymers in isopropyl alcohol

Jonáš

Ward

Atilla

2006

Polymer

View full text Add to dashboard Cite

“…It has been derived for rigid spheres, for non-rigid spheres, for rigid dumbbells and rods, for flexible chains (39,42,94). It has often been proposed for polymer solutions (69,95).…”

Section: General Progression Formula A) General Power Formulamentioning

confidence: 99%

“…For non-spherical rigid particles a-figures of 0.73 for rods (94) and 0.77 for dumbbells (108) have been calculated, and Guth (109) Polymers not always show a linear relation between reduced viscosity and concentration, even at low concentration (42). Often a restricted validity has been found (69), e. g. up to ~r = 1.6 (113), using only ac 2 term.…”

Section: General Progression Formula A) General Power Formulamentioning

confidence: 99%