侧链液晶聚合物的制备及其介电性能  

Preparation and Dielectric Properties of Side-chain Liquid Crystal Polymer

作　　者：祁璐 龚仕洪 刘倚帆 刘剑[1] QI Lu;GONG Shihong;LIU Yifan;LIU Jian(School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)

机构地区：[1]西南科技大学材料科学与工程学院,四川绵阳621010

出　　处：《西南科技大学学报》2021年第4期12-17,72,共7页Journal of Southwest University of Science and Technology

基　　金：环境友好能源材料国家重点实验室自主课题(21fksy26)。

摘　　要：采用原位光聚合的方法合成了带不同长度间隔基团的侧链液晶聚合物PAOCn B(n=0,2,6),通过Agilent-4294A精密阻抗分析仪研究了聚合物在40 Hz~40 MHz频率范围内的介电特性。结果表明,介电常数随柔性间隔基团的长度增加而增大,当n=6时,表现出较高的介电常数(3.48)。通过对介电常数的色散曲线和科尔-科尔(Cole-Cole)图的分析,确定液晶聚合物的介电弛豫类型为近德拜型弛豫。对聚合物的交流电导率分析表明,聚合物薄膜在低频区域(100 Hz~12 k Hz)内,电导率服从量子隧穿机制(QMT);在中频区域(12 k Hz~10 MHz)内,电导率机制符合超线性幂律(SLPL);在高频区域,电导率遵循直流电导率机制。A series of liquid crystal polymers PAOCn B( n = 0,2,6) with different spacer length were synthesized by in-situ photopolymerization method. The dielectric properties were analyzed in the frequency range of 40 Hz-40 MHz at room temperature by using an Agilent-4294 A impedance analyzer. The results indicate that the dielectric constant is increased by the addition of the spacer length. The maximum dielectric constant value of 3. 48 was obtained when the spacer length is 6. By fitting the Debye dispersion curve and Cole-Cole plot,the dielectric relaxation type of liquid crystal polymer is determined to be near Debye model. The conductivity analysis shows that the conductivity follows the Quantum Mechanical Tunneling( QMT) model in the low frequency region( 100 Hz-12 kHz). In the medium frequency region( 12 kHz-10 MHZ),the conductivity mechanism changes to Super Linear Power Law( SLPL) behavior,and the conductivity follows the DC conductivity mechanism in the high frequency region.

关 键 词：液晶 侧链 介电常数 电导率 

分 类 号：O632.52[理学—高分子化学] TQ316.312[理学—化学]