STUDIES ON THE 2 CLASS GLASS-TRANSITION A ND THE TYPICAL VTF BEHAVIOROF AN AMORPHOUS COMB POLYMER ELECTROLYTE

A comb polymer (CP350) with oligo-oxyethylene side chains of the type -(CH2CH2O)(7)CH3 was prepared from methyl vinyl ether/maleic anhydride copolymer and poly(ethylene glycol) methyl ether. The polymer can dis solve LiNO3 salt to form homogeneous amorphous polymer electrolyte. Th is electrolyte system was first found to have two class glass transiti ons, and the two T(g)s were observed to increase with increasing salt content. The ionic conduction was measured by using the complex impeda nce method, and conductivities were investigated as functions of tempe rature and salt concentration. At 25 degrees C, the ionic conductivity maximum of this system can get to 3.72 X 10(-5) S/cm at the [Li]/ [EO ] ratio of 0.057. The appearance of the conductivity maximum has been interpreted as being due to the effect of T-g and the so called physic al crosslinks. The temperature dependence of the ionic conductivity di splaying non-Arrhenius behaviour can be analyzed using the Vogel-Tamma nn-Fulcher equation and interpreted on the basis of the configurationa l entropy model.