Light scattering investigation of interaction between polymers in dilute solution

Abstract

SynopsisParameters characterizing the interaction of nonidentical polymer molecules in dilute solutions of mixtures of two polymers have been defined on the basis of Stockmayer's theory of light scattering in multicomponent systems. Various procedures for evaluation of the interaction parameters from experimental data have been compared. Specific features of the investigation of such interactions are demonstrated with the scattering behavior of the system polystyrene-poly-(methyl methacrylate)-dioxane.

Application of integral‐equation theory to aqueous two‐phase partitioning systems

“…Tables 7, 8, and 9 report experimental cross osmotic second virial coefficients for several polymer pairs, polymer-protein pairs, and (globular) protein pairs, respectively. With the individual osmotic second virial coefficients, weight-average molecular weights and specific refractive-index increments known for the two macromolecules, the cross osmotic second virial coefficient, B,, was determined from the limiting slope of a plot of K' ( c i + c j ) / & as a function of total polymer concentration ( ci + cj) according to the linear relationship (Kratochvil et al, 1975), where The cross specific-interaction coefficient, Pij, is regressed from the cross osmotic second virial coefficient for the macromolecule pair by relating the model (as written for a ternary solution) with the osmotic virial expansion truncated after the second virial coefficient term: …”

Light Scattering Studies on Ternary Polymer Blend Solutions Comprising Poly(hydroxybutyrate)

“…The interaction parameters between the polymers can be determined with Equation (9) and use of Equation (12). It follows…”

“…The terms in Equation (4) are applied to ternary blend solutions. [12,20] Apparent quantities of the ternary system may be expressed in terms of the corresponding binaries. For the apparent molecular mass and the apparent radius of gyration, we get simply additivity relations since these quantities are coefficients of first order terms in concentration.…”

“…[12][13][14][15][16][17][18][19] Light scattering data yield the second virial coefficient. In the Flory-Huggins approximation, the second virial coefficient for polymer blend solutions can be represented by an additivity term and an excess term with respect to blend composition.…”

Limits of the chemical composition heterogeneity of random copolymers

“…Equation (4) is employed to estimate the statistical heterogeneity as. (2) If the statistical heterogeneity Qs can be neglected compared with the conversion heterogeneity Q,, the latter will determine the maximum overall chemical heterogeneity, and vice versa. (3) If the two types of chemical heterogeneity are comparable as to their magnitude, no unequivocal statement can be made regarding the overall chemical heterogeneity.…”