导电聚合物聚醚聚氨酯的结构与导电性能的正电子湮没研究

INVESTIGATIONS OF THE STRUCTURAL AND CONDUCTIVE PROPERTIES OF CONDUCTING POLYMER PEU BY POSITRON ANNIHILATION

用正电子湮设方法研究了高分子固体电解质聚醚聚氨酯（ＰＥＵ）在与ＬｉＣＩＯ＿４络合前后的结构变化及导电性能．实验结果表明，当ＰＥＵ与ＬｉＣＩＯ＿４络合后，正电子素（ｏ－Ｐｓ）的寿命及其强度均减少，而中间寿命分量的湮没参数基本不变．这表明Ｌｉ杂质主要扩散在无序的非晶区．掺杂前后样品的温度实验表明，在玻璃化转变温度Ｔ＿ｇ之下，络合前后的自由体积分数的变化很小，这与自由体积理论预言的结果一致．在Ｔ＿ｇ之上，络合后的自由体积空洞的浓度和自由体积分数均减小．此外，ＰＥＵ－ＬｉＣＩＯ＿４络合物的电导率随温度和Ｌｉ杂质浓度的变化可以用自由体积理论解释．

Positron annihilation lifetime spectra have been measured for polymer electrolyte poly(ether urethane) (PEU). The variations of the positron annihilation parameters as a functionof Li - dopant concentration show that the Li - dopants diffuse mostly into the amorphous re gions. The temperature dependances of the o - Ps lifetime and its intensity give the informa tion about the structural transition of PEU and PEU - LiCIO_4. The relation between the conductivity of PEU - LiClO_4 and temperature can be explained by the theory of free volume.