Effects of coronands on ionic conductivities of complexes of poly[2-(4-vinylphenoxy)-2,4,4,6,6-penta(methoxyethoxyethoxyethoxy)cyclotriphosphazene] with LiClO4

The effects of coronands such as crown ether and azacrown on the conductivity of complexes of LiClO4 with poly[2-(4-vinylphenoxy)-penta(methoxyethoxyethoxyethoxy)cyclotriphosphazene] [poly(STEP)] were investigated. The extent of Tg elevation of poly(STEP)-LiClO4 with 18-crown-6 was comparable to that of the poly(STEP)-LiClO4 system. A similar behavior was observed for the system containing 12-crown-4. However, the increase in Tg values is considerably suppressed when tetraazacyclotetradecane with methoxyethoxy group as a side arm (MTAC) is used. All of the additives are effective to improve the conductivity, and the maximum conductivities of 10−4 S/cm at 30°C and 10−3 S/cm at 90°C have been achieved for the complex of the poly(STEP)-LiClO4-MTAC system with Li+/O = 0.06, which are 3.5–7 times higher than those of poly(STEP)-LiClO4 complexes. From the behaviors of Tg elevation and the conductivity, the role of the coronands for the conduction of the multi-armed poly(STEP)-LiClO4 system is discussed.