脂肪族聚酯与高氯酸锂络合物的结构与导电性

The Structure and Ionic Conductivity of Aliphatic Polyester-LiClO_4 Complexes

本文通过酯交换反应合成了一系列脂肪族聚丁二酸酯,对他们的结构和性能作了表征。发现聚酯存在多晶现象,其熔点有奇偶性变化规律。探索了由此系列聚酯与高氯酸锂形成的固体电解质的结构和离子导电性。无机盐的加入提高了电解质的玻璃化温度但降低了聚酯的熔点及结晶度。聚酯电解质的晶体类似于聚酯,其无机盐主要溶解于聚酯的无定形区域。聚酯系列电解质的导电率也有偶奇效应,与熔点变化相反;熔点高的电解质导电率低,熔点低的电解质导电率高。电解质的导电率随温度改变而变化,在室温下电解质的导电率可达10^(-6)s/cm。高分子链上侧基的引入将大大降低电解质的导电性。

A series of poly(alkyl succinate)s was synthesized from dimethyl succinate and aliphatic diols by ester-exchange polycondensation and these polymers were characterized by various techuiques. There are polymorphic forms in these polyesters and an odd-even effect for the change of their melting point with carbon mumber in diol. The ionic conductivity and structures of polyester-LiClO_4 complexes were mainly and widely investigated. These complexes are semicrystalline materials with crystallites being aimilar to pure polyesters and LiClO_4 mainly dissolves in the noncrystalline domains of the polymers. The dissolution of the salt into polyester enhances the glass transition temperature of them, but depresses the melting point and crystallinity. Ionic conductvity of the electrolytes varies with the carbon number in diol. The lower the melting temperature of polyester, the higher the conductvity of its electrolyte. The conductivity of the complexes increases nonlinearly with increasing temperature as shown in the Log(σ) vs. 1/T plots and some of them could reach as high as 10^(-6)s/cm at ambient temperature. The presence of side group in polyester chain would largely reduce the conductivity of the electrolyte.