聚丁二酸丁二酯与高氯酸锂络合物的结构与离子导电性

THE STRUCTURES AND IONIC CONDUCTIVITY OF COMPLEXES OF POLY (TETRAMETHYLENE SUCCINATE) AND LITHIUM PERCHLORATE

本文从丁二酸二甲酯和丁二醇合成了聚丁二酸丁二酯,并以高氯酸锂为掺杂剂制备了固体电解质。FT-IR、NMR、XPS测试发现酯基上的氧原子参与络合。WAXD、DSC等测试分析结果表明:络合物和聚酯的晶体相同;LiClO_4主要溶解在无定形区;盐的溶解降低聚酯的熔点、结晶度和结晶速度,而提高玻璃化温度;在低盐浓度区络合物熔点与盐浓度关系符合Flory-Huggins理论。络合物的电导率随盐浓度变化出现极大值,在低盐浓度区电导率与浓度的对数成线性关系。电解质的导电行为不能简单地为Arrhenius和WLF方程所解释。从扩散角度推导了导电方程,并描述了离子导电过程。

Poly (tetramethylene succinate) (PTS-4,4) is synthesized from dimethyl succinate and bu-tanediol and solid polymeric electrolytes are made by dissolving lithium perchlorate in the polyester. The complexation between ions and oxygens of ester groups is found with FT-IR, NMR, and XPS techniques. The analytical results of WAXD and DSC show that PTS-4,4-LiClO4 complexes have the same crystallites as PTS-4, 4. LiClO4 mainly dissolves in the amorphous region of the polymer. The dissolution of the salt depresses the melting temperature, the crystallization degree and rate, but raises the glass transition temperature of PTS-4, 4. The relation of the melting temperature and salt content of the electrolytes corresponds with Flory-Huggins theory within lower salt concentration. The ionic conductivity of PTS-4,4-LiClO4 complexes varies with the salt concentration and there is a maximum. Particularly, the logarithm of conductivity is linear with that of salt concentration in the range of lower concentration. The conductive behavior of PTS-4, 4-LiClO4 complexes could not simply be explained by Arrhenius or WLF equation. The conductive equation is inferred from diffusion theory and the process of ion migration in polyester is described in this article.