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ABSTRACT:Comb-like polymers (CP) based on modified alternating methyl vinyl ether/maleic anhydride copolymer with oligo-oxyethylene side chains of the type --O(CH 2CH 2O).CH 3 have been synthesized and characterized, and complexed with lithium salts to form amorphous polymer electrolytes. CP /salt complexes showed conductivity up to 1 o-5 S cm -1 at room temperature. The temperature dependence of ionic conductivity suggests that the ion transport is controlled by segmental motion of the polymer, shown by linear curves obtained in Vogel-Tammann-Fulcher plots. The ionic conductivity maximum moves to a higher salt concentration as the temperature increases. IR results indicate that the ester in CP might decompose at 140°C and reproduce the maleic anhydride ring. The high ionic conductivities which have been observed in polymer/alkali metal salt complexes, particularly those involving poly(ethylene oxide) (PEO) and lithium salts, have stimulated great interest in these systems as electrolytes for all solid-state, high-energydensity batteries. 1 · 2 The ion-conducting polymers can also be used as solvent-free electrolytes or electrode materials in sensors and electrochromic displays. During the past 20 years, the study of solid polymer electrolytes (SPE) has been very active. 3 -5 PEO, the most extensively studied polymer, can form complexes with a wide range of metal salts including alkali, alkaline earth, and transition metal salts. PEO/salt electrolytes suffer from one major drawback in that PEO is semicrystalline at ambient temperature. NMR studies indicate that ion transport occurs in the amorphous regions of the polymer and, taken together with temperature dependence measurements, implicate polymer segmental motion in the conduction mechanism. 3 High and valuable ionic conductivities can only be obtained after the temperature of the system exceeds the melting point of PEO, which is about 338 K. In order to destroy the crystallinity of PEO and obtain totally amorphous electrolyte materials, many researchers choose the method to prepare comb polymers by attaching short ethylene oxide (EO) unit sequences to an existing polymer backbone. A lot of comb polymers with oligo-oxyethylene side chains have been prepared by using polymethacrylate, 6 -10 polyglutamates, 11 -13 polysiloxane, 14 -16 polyphosphazene, 1 7 -22 and poly(itaconic acid) 23 ' 24 as the polymer backbone. These systems all show higher room temperature conductivities, when complexed with alkali metal salts, than those corresponding PEO/salt electrolytes. KEY WORDSAlternating maleic anhydride copolymers are a group t To whom correspondence should be addressed. 410of high reactive bifunctional polymeric materials and are commercially available. Recently, Rietman and coworkers25 have synthesize single-ion (Li) conducting polymer by reacting monomethyl ether with either poly-(styrene-a/t-maleic anhydride) or poly(ethylene-alt-maleic anhydride) and then treating with LiOH solution to form lithium salt. Just like other single-ion polymeric electrolytes, thei...