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Evaluation of K ⊖ from [η]‐ M ‐data of binary and ternary polymer systems
Author(s) -
Zisenis Mathias,
Springer Jürgen
Publication year - 1992
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19920610124
Subject(s) - virial coefficient , thermodynamics , ternary operation , linearity , molar mass , intrinsic viscosity , viscosity , curvature , binary number , solvent , polymer , dimension (graph theory) , mathematics , chemistry , materials science , physics , combinatorics , organic chemistry , quantum mechanics , geometry , arithmetic , computer science , programming language
Unperturbed dimensions of flexible linear macromolecules can be obtained from [η]‐ M ‐data in any solvent, good or poor, single or mixed. Usually K θ is estimated by a relationship between [η]/ M W 0.5 and M w 0.5 first proposed by Burchard and by Stockmayer and Fixman. But, it is well‐known that the Burchard‐Stockmayer‐Fixman‐plot shows downward curvature, especially for good solvent systems. Various efforts have been made to achieve relations with better linearity. One of the first was the semi‐empirical relation between ([η]/ M w 0.5 ) 0.5 and M w /[η] by Berry. Predicting a relationship of the excluded volume parameter z to the viscosity expansion factor by α 5 η instead of α 5 η Tanaka obtains that ([η]/ M w 0.5 ) 5/3 is linear in M w 0.5 . By allowing for the dependence of the viscometric interaction parameter B , which is correlated to the second virial coefficient A 2 , on molar mass, Gavara, Campos and Figueruelo predict a linear dependence of [η]/ M w 0.5 against A 2 .M w 0.5 . It is not our intention here to discuss the validity of these theories, but to compare them with experimental data.