ISSN:
1435-1536
Keywords:
Binary polymer mixtures
;
dilute solutions
;
semi dilute solutions
;
overlap concentrationc *
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Using viscometry techniques on polymer fractions, we determine the critical concentrationc * (separating the dilute and semi dilute solutions). The same measurements have been conducted with mixtures of these fractions (mixtures 1:1 by weight of fractions differing in molecular mass and chemical nature, or fractions differing only in molecular mass). The determined values of critical concentrationc * of the mixtures are higher than the values calculated based on the critical concentrations of the corresponding fractions. This deviation from the additivity rule is attributed to the resistance in the interpenetration (delay to the attainment of the homogeneous state) between macromolecular coils of different chemical nature or of the same chemical nature but of different molecular mass. Higher values of the reduced viscosities of the mixture of the fractions, compared to the values calculated using the reduced viscosities of the corresponding fractions, are observed above the critical concentrationc *. In this concentration region the interaction parameter between two different polymers is calculated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00653060
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