Cure Kinetics and Mechanical Properties of Liquid Crystalline Epoxides with Long Lateral Substituents Cured with Anhydride
Cure Kinetics and Mechanical Properties of Liquid Crystalline Epoxides with Long Lateral Substituents Cured with Anhydride
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DOI：
10.1295/polymj.pj2006219
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发表时间：
2007-09
期刊：
影响因子：
2.8
通讯作者：
Liyan Liang;Shaoping Ren;Yiquan Zheng;Yanxun Lan;Mangeng Lu
中科院分区：
文献类型：
--
作者：
Liyan Liang;Shaoping Ren;Yiquan Zheng;Yanxun Lan;Mangeng Lu
用酸酐固化了一系列具有不同侧链取代基长度的液晶环氧单体。采用DSC技术研究了固化动力学。用多温扫描法测定了不同侧链取代基长度的环氧化合物的反应活化能Ea和频率因子A，并进行了比较。结果表明，随着侧链取代基长度的增加，固化反应的活化能Ea减小，但固化反应活性降低，固化后期受扩散控制。采用POM、WAXD、DMA、拉伸试验和SEM等方法研究了LC环氧树脂的相结构和力学性能。观察到一种非线性结构。随着侧链取代基长度的增加，液晶网络的交联密度和玻璃化转变温度（Tg）降低。拉伸模量、断裂强度和断裂伸长率也随侧链的增加而降低。
A series of liquid crystalline (LC) epoxy monomers with different length of lateral substituents were cured with anhydrides. The cure kinetics was investigated by DSC technique. From a multi-temperature scan method, the activation energy Ea and the frequency factor A were determined and compared for epoxides with different length of lateral substituents. The results showed that as the length of lateral substituent increases, the activation energy Ea de- creases, but the curing reaction of liquid crystalline epoxides become less active and is controlled by diffusion at the late stage of curing. The phase structures and the mechanical properties of the resulted LC epoxy resins were studied by POM, WAXD, DMA, tensile tests and SEM. A nematic structure is observed. And as the length of lateral substituent increases, the cross-linking densities and glass transition temperature (Tg) of the LC networks decreases. The tensile modulus, together with break strength and elongation at break also decreases as the side chain increasing.