Sub-Tg relaxation in LiClO4-poly (propylene glycol)-2000 solutions

David L. Sidebottom, G. P. Johari

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The dielectric permittivity and loss of LiClO4 solutions in poly(propylene glycol (PPG)), molecular weight 2000, have been measured over a concentration range up to a ratio of Li+ to oxygen atoms in PPG of 33.3:100, between 77 and 350 K. The data have been analyzed in both the permittivity and electrical modulus formalisms. Addition of LiClO4 to poly(propylene glycol) first increases the height of the β-relaxation peak, and ultimately a second sub-Tg relaxation peak at a higher temperature emerges. This is in addition to the β-relaxation peak due to the reorientation of PPG dipoles, whose strength decreases from that in pure PPG-2000. For a fixed temperature, the dc conductivity initially decreases with increasing Li+ concentration up to 20 Li+ per 100 O atoms and thereafter increases. This concentration corresponds to that at which the Tg of the solution reaches its limiting value of ca. 310 K. It is concluded that the formation of ion pairs causes a second and slower sub-Tg relaxation process and that the increase in the efficiency of chain packing reduces the strength of the β-relaxation of the polymer.

Original languageEnglish
Pages (from-to)1215-1221
Number of pages7
JournalJournal of Polymer Science, Part B: Polymer Physics
Volume29
Issue number10
DOIs
StatePublished - Sep 1991
Externally publishedYes

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Propylene Glycol
Glycols
propylene
Propylene
glycols
polypropylene
Polypropylenes
Permittivity
permittivity
Atoms
Relaxation processes
retraining
lithium perchlorate
molecular weight
oxygen atoms
Polymers
Molecular weight
Ions
Oxygen
dipoles

All Science Journal Classification (ASJC) codes

  • Polymers and Plastics
  • Materials Chemistry

Cite this

Sub-Tg relaxation in LiClO4-poly (propylene glycol)-2000 solutions. / Sidebottom, David L.; Johari, G. P.

In: Journal of Polymer Science, Part B: Polymer Physics, Vol. 29, No. 10, 09.1991, p. 1215-1221.

Research output: Contribution to journalArticle

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