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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?

✍ Scribed by Yongjin Wang; Kara T. Williams; Lei Li


Publisher
John Wiley and Sons
Year
2011
Tongue
English
Weight
667 KB
Volume
212
Category
Article
ISSN
1022-1352

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✦ Synopsis


Abstract

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 ηM relationship of DPFPO.