新型甲基丙烯酸酯类接枝共聚物电解质的制备与表征

Synthesis and characterization of novel graft copolymer electrolytes based on methacrylates

以甲氧基聚乙二醇甲基丙烯酸酯(MPEGM)和十六烷基聚乙二醇甲基丙烯酸酯(HPEGM)为单体,采用自由基溶液聚合法制备无规接枝共聚物P(MPEGM-HPEGM),并以此共聚物为基体混合锂盐(LiClO4)制备全固态聚合物电解质。用红外光谱(FT-IR)、差热分析(DSC)和交流阻抗(EIS)等方法对聚合物和聚合物电解质的性能进行研究。结果表明:MPEGM和HPEGM共聚生成P(MPEGM-HPEGM);聚合物中聚氧化乙烯(PEO)链段的运动能力得到提高,有利于离子传输;聚合物电解质膜的电化学稳定性窗口达到4.5 V;在30℃时,当MPEGM与HPEGM的质量比为80∶20,锂盐与氧化乙烯(EO)的摩尔比为1∶20时,聚合物电解质的离子电导率达到最高7.6×10-5S/cm;离子电导率随着温度的升高而迅速增加,电导率-温度的关系符合VTF方程。

A novel graft copolymer P（MPEGM-HPEGM） was prepared by co-polymerizing of two macro- monomers ： methoxy-poly （ ethylene glycol） methaerylate （MPEGM） and hexadecal-poly （ ethylene glycol） methaerylate （HPEGM）. And the polymer electrolytes were prepared by blending P（MPEGM-HPEGM） and LiC104. The performances of the polymer and polymer electrolytes were studied by Fourier transform infrared spectrometry （ FT-IR ）, differential scanning calorimetry （ DSC ） and electrochemical impedance spectroscopy （EIS）. The results showed that P （MPEGM-HPEGM） was successfully synthesized and the motion of poly （ ethylene oxide） （PEO） chains was improved. The electrochemical stability of the polymer electrolytes was up to 4. 5 V. When the weight ratio of MPEGM to HPEGM was 80：20 and the mole ratio of lithium salt to ethylene oxide （EO） was 1： 20, the maximum ionic conductivity reached 7.6×10^-3S/cm at 30 ℃. The temperature dependence of ionic conductivity of solid polymer electrolytes appeared to obey Vogel-Tamma-Fuleher （VTF） equation.