低介电损耗苯并噁唑复合材料的合成与表征

对介孔二氧化硅SBA 15进行氨基官能团化，制得NH2-SBA-15，通过溶液缩聚合成了一系列具有不同SBA-15质量分数的聚亚苯基苯并二噁唑/SBA-15（PBO/SBA- 15）复合材料。利用红外光谱（FT-IR）、扫描电子显微镜（SEM）、热重分析（TG）和矢量网络分析仪（VNA）分别对复合材料的结构、微观形貌、热性能和电磁性能进行了表征与分析，研究了SBA-15对PBO/SBA-15复合材料介电参数的影响。研究表明：经过氨基官能团化之后，SBA-15能够均匀地分散在PBO基体中；当复合材料中SBA-15的质量分数小于8%时，PBO/SBA-15复合材料仍然保持着PBO优异的热稳定性；介孔二氧化硅SBA-15能够有效地降低PBO/SBA-15复合材料的复介电常数和介电损耗角正切，减弱PBO/SBA-15复合材料对电磁波的介电存储和损耗能力，使PBO/SBA-15复合材料表现出低介电损耗的性能。

Synthesis and Characterization of Polybenzoxazoles Composites with Low Dielectric Loss

NH2-SBA-15 was prepared by amino group functionalization to mesoporous silica SBA-15. Then a series of polybenzoxazole/SBA-15 (PBO/SBA- 15) composites with different SBA-15 contents were prepared via solution polycondensation. The structure, morphology, thermal property and electromagnetic properties of composites were characterized by FT-IR, SEM, TG and VNA, respectively. And the effect of SBA-15 on the dielectric loss of PBO/SBA-15 composites was studied. Results demonstrate that NH2-SBA-15 could disperse in PBO matrix uniformly. And the prepared PBO/SBA-15 composites still maintain an outstanding thermal stability when the mass fraction of SBA-15 is below 8%. The introduced SBA-15 could reduce the complex permittivity and dielectric loss tangent of PBO and result in a reduced dielectric storage and loss performance of PBO/SBA-15 composites to electromagnetic wave energy, making PBO/SBA-15 composites show low dielectric loss property.