Preparation and ionic conductivity of poly(oligo(oxypropylene) methacrylate)

Abstract

Poly(oligo oxypropylene) methacrylate (P(MPO)) was prepared, and a series of alkali metal perchlorates (MClO 4; M = Li, Na, K, Rb and Cs) was dissolved in it to measure ionic conductivity. The lithium ionic conductivity was ∼ 10 −6 S cm −1 at 303K, and the conductivity decreased monotonously with increasing radius of the alkali metal cation. This tendency was totally the inverse to that observed for the poly(ethylene oxide) derivatives. As the solubility of LiClO 4 was higher than for other perchlorate salts, various lithium salts were dissolved to investigate the effect of the anion on ionic conductivity. The ionic conductivity decreased with increasing lattice energy of the salts. Arrhenius plots of ionic conductivity and glass transition temperature measurements indicated that ionic conductivity was mainly governed by the solubility of the salt in P(MPO). The dissociation energy of the salt is important for ionic conductivity when salts with higher solubility in PPO were used. In a poly(propylene oxide) derivative, the solubility of the salts was concluded to be the most important factor for ionic conductivity.