Preparation and Dielectric Properties of High Temperature Resistant Barium Titanate/ Benzoxazole Nano-Composites
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摘要: 合成了一种新型的热固性苯并噁唑树脂(NPBO),并采用化学接枝的方法制备了聚氨酯包覆钛酸钡核壳结构纳米粒子(PU@BT),将PU@BT与NPBO树脂复合,制备了PU@BT/NPBO纳米复合材料。对NPBO的化学结构和热固化行为进行研究,采用扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察了PU@BT的微观形貌,采用宽频介电谱仪测量了复合材料的介电性能。研究结果发现:随着PU@BT的体积分数由0提高到10%,复合材料的介电常数大幅提高。在1 kHz时,纯NPBO的介电常数为3.3,而加入10 vol% PU@BT后,复合材料介电常数为7.3,相对纯NPBO的介电常数提高了1.21倍。Abstract: High temperature and high dielectric constant polymer nanocomposites have attracted widespread attention in pulse power system. such as mobile electronics, electric vehicles and electronic equipment ,which due to their processing flexibility, light weight, and low cost. Herein, a new type of thermosetting benzoxazole high-temperature resistant resin NPBO was synthesized by chemical methods. The chemical structure and thermal curing behavior of NPBO were studied by H-NMR , EI-MS spectra and DSC, it proved excellent thermal properties. At the same time, the stepwise reaction and chemical grafting were used to prepare polyurethane-coated barium titanate core-shell hybrid nanoparticles (PU@BT), and then the PU @BT and NPBO resins were compounded according to different components to prepare PU@BT/NPBO nanocomposites. Use scanning electron microscope (SEM) and transmission electron microscope (TEM) to observe the morphology of PU@BT. and particles are evenly coated and showed a good dispersion performance. Finally, the dielectric properties of the composite materials are measured by a broadband dielectric spectrometer. It is found that as the volume fraction of PU@BT increases from 0 to 10%, the dielectric constant of the composite material increases significantly. At 1 kHz, the dielectric constant of NPBO is 3.3, and when 10% PU@BT is added, the dielectric constant of the composite is 7.3, which is an increase of 1.21 times. The composite material provides a theoretical basis for its application in the field of dielectrics.
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Key words:
- benzoxazole /
- barium titanate /
- dielectric properties /
- dielectric constant /
- composite.
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表 1 NPBO树脂在不同加热速率下的固化特性参数
Table 1. Curing characteristic parameter of NPBO resin at different heating rates
${ \rm{{Heating rate /(^{o}C\cdot min^{-1} )}} }$ Ti /oC Tp /oC Tt /oC 5 181.6 207.3 228.1 10 193.4 215.2 232.5 15 202.0 223.1 237.7 20 208.8 228.9 244.1 25 213.3 234.0 249.3 Ti is the initial curing temperature; Tp is the peak curing temperature; Tt is the final curing temperature. -
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