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Understanding the Mechanism of Anomalous Viscosity–Molecular Weight Relationships of Diolic Perfluoropoly (Oxyethylene‐ran‐oxymethylene): What is Missing in the Debye–Bueche Model?
Author(s) -
Wang Yongjin,
Williams Kara T.,
Li Lei
Publication year - 2011
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201100459
Subject(s) - intermolecular force , viscosity , thermodynamics , polymer , chemistry , debye , polar , coupling (piping) , polymer chemistry , linear polymer , materials science , organic chemistry , molecule , physics , astronomy , metallurgy
For decades, the viscosity ( η )–molecular weight ( M ) relationship of linear polymer melts has been successfully described by the Debye–Bueche model when M is lower than critical molecular weight ( Mc ). However, recent studies on diolic perfluoropoly (oxyethylene‐ran‐oxymethylene) (DPFPO), a linear polymer with polar endgroups, raise uncertainty on the validity of Debye–Bueche model. Experimental results show that the Debye–Bueche model does not hold for DPFPO, which has been attributed to the fact that the strong intermolecular endgroup–endgroup coupling is not considered in original Debye–Bueche model. A modified molecular‐level model, in which the endgroup–endgroup coupling is taken into consideration, is proposed to interpret the anomalous η – M relationship of DPFPO.