Effect of temperature and pressure on the dynamic miscibility of hydrogen-bonded polymer blends

K. Mpoukouvalas, G. Floudas, S. H. Zhang, James Patrick Runt

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

The dynamic miscibility of poly(4-vinylphenol)/poly(vinyl ethyl ether) (PVPh/PVEE) blends, with a T g contrast of 186 K, as well as the PVEE segmental dynamics have been investigated by temperature- and pressure-dependent dielectric spectroscopy. In PVEE the pressure coefficient of T g amounts to 0.215 K/MPa, and its apparent activation volume displays the usual T dependence. Although both temperature and volume contribute to the segmental dynamics, the former has a stronger influence within the T and P investigated. In the blends, dynamic heterogeneity is suppressed because of hydrogen bonds that couple the components' segmental dynamics. In the PVEE-rich blends, increasing temperature and pressure results in the broadening of the distribution of relaxation times through the weakening of hydrogen bonds and the associated decoupling of the segmental dynamics. A central result of the present study is the identification of a critical temperature above which the system becomes increasingly heterogeneous.

Original languageEnglish (US)
Pages (from-to)552-560
Number of pages9
JournalMacromolecules
Volume38
Issue number2
DOIs
StatePublished - Jan 25 2005

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this