Glass transition, crystallization and thermoreversible gelation in ternary PPO solutions; relationship to asymmetric membrane formation

W. R. Burghardt*, L. Yilmaz, A. J. McHugh

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

61 Scopus citations

Abstract

The phase equilibrium behaviour of PPO (poly 2,6-dimethyl-1,4-phenylene oxide) in mixtures of trichloroethylene with non-solvents ethanol, methanol or octanol has been studied. Attention has been given to the phenomena of glass transition, crystallization and thermoreversible gelation. The effect of solvent-non-solvent mixtures on the glass transition temperature depression was studied using differential scanning calorimetry (d.s.c.) and found to be well described by a ternary form of the Kelley-Bueche equation, using a modified best fit value of 3.67 for the solvent/polymer thermal expansivity ratio. Crystallization and gelation behaviour was studied using both d.s.c. and falling ball methods. D.s.c. scans showed a two-peaked behaviour when solvent trichloroethylene (TCE) or mixtures of TCE with octanol were used. Analysis showed that gel and crystal melting (associated with the higher temperature peak) are in a one-to-one correspondence and both exhibit a behaviour pattern with solvent concentration suggestive of simple melting point depression. However, addition of small amounts of non-solvent methanol or ethanol had a significant effect on the melting behaviour in that only a single endotherm resulted, whose depression in temperature could not be accurately described using the ternary form of the Flory melting point expression. A semiquantitative discussion is given emphasizing the role of these phenomena in controlling both the nature of the ternary phase diagram and the structure formation Processes associated with asymmetric membrane production.

Original languageEnglish (US)
Pages (from-to)2085-2092
Number of pages8
JournalPolymer
Volume28
Issue number12
DOIs
StatePublished - Jan 1 1987

Keywords

  • PPO
  • crystallization
  • gelation
  • glass transition
  • membranes

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Glass transition, crystallization and thermoreversible gelation in ternary PPO solutions; relationship to asymmetric membrane formation'. Together they form a unique fingerprint.

Cite this