Ionically conducting networks derived from PEO containing aziridine groups

Abstract

Aziridine-modified poly(ethylene oxide)s (PEOs) were obtained via 1,3-dipolar addition of α,ω-unsaturated PEO onto 3,3′-diazidodiphenyl sulfone. The unsaturated telechelic functions used were allyl and methacrylate. To establish the structure of the condensation products, unsaturated model compounds of low molecular weight were also reacted with the same azide. The formation of a mixture of aziridine and triazoline functionalized compounds was proved when the unsaturation was of allylic type. Only aziridine function was detected in the case of methacrylate-type unsaturation. The polymers containing aziridine functions were crosslinked by cationic ring opening polymerization of the aziridine units. The introduction of nitrogen-containing heterocycles into the poly(ethylene oxide) backbone and their transformation into amine bridges induced an increase of the glass transition temperature (Tg) of the modified linear and crosslinked polymers as compared to the unmodified PEOs. Reciprocal Tg was shown to increase linearly when lithium trifluoromethanesulfone imide was introduced into the networks. Conductivity measurements were carried out and a maximum ionic conductivity of 6.10−6Scm−1 at O/Li = 20 at room temperature was achieved. © 1999 Society of Chemical Industry