2017届硕士毕业生
发布人： 网站管理员 发布时间: 2020-06-30 作者: 访问次数: 37

论文题目：聚醚砜/纳米氧化铝/环氧树脂复合材料的制备与性能研究

 

  

毕业学生：陈诗英

 

  

指导教师：吴唯

 

  

中文摘要：

   

  环氧树脂（Epoxy, EP）因为固化收缩率低、制品尺寸稳定和电绝缘性能优异等特点，广泛地应用于电子电器领域。然而固化环氧树脂交联密度大，耐冲击强度较差，且随着电子设备的革新和智能化发展，传统的环氧树脂已经难以满足现阶段提出的更高介电常数的性能要求，这对 EP 在电子绝缘材料领域的使用造成了限制。因此，制备出具有优异的机械性能和介电性能的环氧树脂复合材料，将具有巨大的潜在应用前景。随着环氧改性技术的发展，两种增韧剂协同作用改善的 EP 的韧性，成为一种非常有效的方法，能够制备出性能更为优良的环氧基复合材料。
  本文选择环氧树脂 E-51 为基体，以聚醚砜（PES）作为增韧增强材料，分别使用 4,4’-二氨基二苯砜（DDS）和甲基纳迪克酸酐（MNA）作为固化剂，通过综合热分析仪（TG）、万能拉力试验机和宽频介电谱仪等测试分析手段，对比最终固化产物的力学性能、热稳定性能和介电性能等，而且对固化剂种类和 PES 含
量对复合固化体系的影响进行了研究，并确定最佳性能的配方。研究结果表明：对于 DDS 固化体系，当 EP/PES=100/5 时体系的综合性能最好，拉伸强度、弯曲强度和冲击强度比纯的 EP 体系分别提高了 34.8%、25.0%和 3.3%；对于 MNA 体系，当 EP/PES=100/15 时体系的综合性能最好, 拉伸强度、弯曲强度和冲击强度
相比纯的 EP 体系分别提高了 14.0%、59.2%和 11.5%；此外，相比纯的环氧树脂，两个不同的固化体系的热稳定性能和介电常数都有一定幅度的提高。为了进一步提高复合材料的力学性能和介电性能，本文在 EP/PES 复合体系中加入不同含量的硬脂酸改性纳米 Al2O3，制备 EP/PES/Al2O3 复合材料，并且对固化产物进行结构形貌和性能表征。实验结果表明：对于 DDS 体系，当 nanoAl2O3 添加量为 1 phr 时，EP/PES/Al2O3 复合材料的冲击强度、初始分解温度和介电常数（100Hz）分别达到了 22.3 kJ/m2 , 381 oC 和 6.5，比环氧树脂分别提高了48.7 %，37 ℃和 44%。对于 MNA 体系，当 nano-Al2O3 添加量为 3 phr 时，EP/PES/Al2O3 复合体系的冲击强度、初始分解温度和介电常数分别达到 45.7kJ/m2、376 oC、和 7.7，比纯环氧树脂分别提高了 207%、73 oC、和 71%。


  Abstract:

     


     Epoxy resin has been widely used in the field of electrical and electronic because of its low curing shrinkage, stable product size and excellent electrical insulation properties. However, the application of epoxy resin has been limited by its high crosslinking density and poor impact properties. With the development of intelligent electronic equipment, the traditional epoxy resin has hardly satisfied the requirements of high dielectric constant and flexible performance. With the development of epoxy modification technology, introducing two kinds of toughening agents on epoxy resin has become a promising and effective method.
    In this paper, we chose epoxy resin E-51 as matrix resin, PES as toughening material, DDS and MNA as curing agents. The influence of the kind and content of curing agent and PES on the composites curing system were studied. Besides, thethermal stability, mechanical properties and dielectric properties of the composites were  
analyzed by TG, universal tensile testing machine and broadband dielectric spectroscopy. Noticeably, when the mass ratio of EP:PES was 100:5 for DDS curing system, the tensile strength, bending strength and impact strength of curing productwere increased by 34.8%, 25% and 3.3% compared with the pure epoxy resin. But forMNA curing system, when the mass ratio of EP:PES was 100:15, the corresponding value were increased by 14%, 59.2% and 11.5%. In addition, thermal stability and dielectric constant of the two curing systems were certainly improved as well.
    In order to further improve the mechanical properties and dielectric properties, the EP/PES/Al2O3 composites were prepared by adding Al2O3 in the EP/PES composite systems. The experimental results show that when the amount of nano-Al2O3 is 1 phr,the impact strength, the initial decomposition temperature and dielectric constant of EP/PES/Al2O3 composites reached 22.3 kJ/m2 , 381 oC and 6.5 for DDS system, which were increased by 48.7%, 37 oC and 44% compared with pure epoxy resin. But for the MNA system with the 3 phr nano-Al2O3, the impact strength, the initial decomposition temperature and dielectric constant were 45.7 kJ/m2 , 376 oC and 7.7, increased by about 207%, 73 oC and 71% respectively