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Poly(oxyethylene)s terminated at both ends with phosphonium ion end groups, 2. Properties

✍ Scribed by Przemysław Kubisa; Tadeusz Biedroń


Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
504 KB
Volume
197
Category
Article
ISSN
1022-1352

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✦ Synopsis


Abstract

Poly(oxyethylene)s with number‐average degrees of polymerization (DP~n~) ranging from ≈ 6 to ≈ 80, terminated at both ends with phosphonium ion end groups (diionic poly‐EO), have been prepared and characterized as described in the preceding paper. Viscosities of diionic poly‐EO were measured, both in solution and in bulk. In chloroform solution, at low concentration (< 1 g/100 mL), the viscosity of diionic poly‐EO was lower than the viscosity of nonionic (terminated with HO‐groups) poly‐EO of the same DP~n~. At higher concentrations, the viscosity of diionic poly‐EO exceeded that of nonionic poly‐EO and increased sharply with increasing concentration. At the constant weight concentration of ≈4 g/100 mL, the viscosities of short‐chain diionic poly‐EO were higher and those of longer chain diionic poly‐EO were lower than the viscosities of the nonionic poly‐EO of the same chain lengths. These results were attributed to a predominant intramolecular aggregation of terminal ionic groups at low concentration of ionic groups in solution and predominant intermolecular aggregation at higher concentration of ionic groups. The results of bulk viscosity measurements as well as the results of differential scanning calorimetry measurements of the dependence of the glass transition temperature on the DP~n~ of diionic poly‐EO indicated that in bulk physically cross‐linked networks were formed, due to intermolecular aggregation of terminal ionic groups.


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