Chemical Modification of Poly(ethylene imine) for Polymeric Electrolyte.

Linear PEI has been chemically modified in an attempt to prevent formation of a crystalline complex without altering its ability to dissolve salts and conduct ions. Three main systems were investigated a polyN-acetylethylene imine, b partially quaternized PEI with ethyl or butyl groups, and c PEI cross-linked with diepoxyoctane. Dissolution of salt was followed by x-ray diffraction on the mixtures and changes in T sub g as determined by DSC. In all cases, the crystallinity was destroyed but conductivity of salt-containing polymer was not improved. However, lightly cross-linked PEI exhibits much improved mechanical properties and the incorporation of .05 mole NaImole of monomer yields a conductivity of .00005 Scm at 100 C. Author