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Positron annihilation lifetime spectroscopy as a probe of free volume in plasticized solid polymer electrolytes

journal contribution
posted on 01.10.1995, 00:00 authored by Maria ForsythMaria Forsyth, P Meakin, D MacFarlane, A Hill
A recent report on the correlation between enhanced polymer mobility and ionic conductivity at room temperature in plasticized polyether-urethane solid polymer electrolytes (Forsyth et al.[1]), has prompted the present investigation. Positron annihilation lifetime spectroscopy (PALS) has been used to study the effect of plasticizer addition on the room temperature free volume characteristics of the crosslinked polyether-urethane. The addition of low molecular weight plasticizers to the polyether-urethane results in a constant or decreasing mean free volume cavity radius, as measured by the orthoPositronium lifetime τ3, and a decreasing relative concentration of free volume cavities as measured by the ortho-Positronium intensity, I3. It is postulated that the plasticizers interrupt polymer-polymer interactions by occupying the inter- and intra-chain free volume. The plasticizer structure influences the polymerplasticizer interactions which affect inter- and intra-chain separation and hence the free volume of the system. The decrease in polymer-polymer interaction and the increase in polymer-plasticizer interaction in turn influence the glass transition temperature behaviour.

History

Journal

Electrochimica acta

Volume

40

Issue

13-14

Pagination

2349 - 2351

Publisher

Elsevier Science Pub. Co.

Location

New York, N.Y.

ISSN

0013-4686

eISSN

1873-3859

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1995, Elsevier Science Ltd.