聚丁二酸乙二酯-碘化钠络合物的导电性

Study on the Ionic Conductivity of Polymeric Complexes Formed by PES-2, 4 and NaI Salt

考查了由聚丁二酸乙二酯(PES-2,4)和NaI形成的络合物结构和导电性的关系,发现NaI主要溶解在高分子的无定形区域;PES-2,4与NaI形成的络合物体系是半结晶的聚合物电解质,其结晶体的结构类似于纯PES-2,4。NaI的加入,使聚合物的玻璃化转变温度、结晶化转变温度均升高,而结晶度和结晶速度降低。电解质的导电率随NaI浓度变化而变化,NaI浓度高,其导电率高,当[NaI]/(链节单元]=1/4(摩尔浓度比)时,电解质的导电率可达10~■S/cm(90℃),其中无定形区的导电是主要的。导电率与温度的关系偏离阿累尼乌斯方程,伹也不完全符合WLF方程,导电行为不可简单地用它们来解释。

The relationship between molecular characteristics and electrical conductivity of poly(ethylene succinate)(PES-2,4)-sodium iodide complexes is investigated in the present article. NaI is mainly dissolved in the amorphous domains of the polyester. The PES-2,4-NaI complexes are semicrystalline electrolytes with crystallites similar to pure PES-2,4. The dissolution of NaI enhances the glass transition temperature T_g and the crystallization temperature T_C and depresses the degree and rate of crystallization. The ionic conductivity of the complexes to which the amorphous region primarily contributes varies with the content of NaI. The higher the concentration of NaI in the electrolyte, the higher the conductivity of the electrolyte. The conductivity of the complex with [NaI]/[unit] = 1/4 can reach the order of magnitude 10^(-6) S/cm at 90℃. The temperature dependence of the conductivity of PES-2, 4-NaI electrolytes is explored with Arrhenius and WLF equations by the fitting calculation. The conductive behavior seems to deviate from those equations. Therefore, it could not be simply explained by WLF equation based on the free volume theory or Arrheous's on the classical theory.