023型铌镁锆钛酸铅/环氧树脂复合材料的介电和阻尼性能

采用树脂浇注成型法制备了 023型铌镁锆钛酸铅(PMN) /环氧树脂( EP)复合材料 , 并用差示扫描量热仪(DSC)研究了 PMN对环氧树脂固化性能的影响。介电性能研究表明 , 随着 PMN质量分数的增加 , 介电常数和5介电损耗都呈非线性增大 ; 在小于 10 Hz频率范围内 , 介电常数随频率增大迅速降低 , 这主要是受复合材料界面极化影响 , 频率较高时 , 介电常数变化较小 , 表现出较好的频率稳定性 ; 在测试频率范围内 , 介电损耗随频率的升高略有降低 , 但变化幅度很小。动态热机械分析(DMA)表明 , 复合材料的储能模量随 PMN 含量的增加而增大 , 损耗模量和阻尼损耗因子的峰值及阻尼温域受 PMN含量的影响较大 , 当 PMN 含量为 87. 24 wt %时在 90℃附近观察到新的阻尼损耗因子峰出现 , 且该峰对应的温度不随频率的改变而移动 , 该阻尼损耗因子峰可能为复合材料的介电损耗耗能所致。

Dielectric and damping properties of 023 PMN/ epoxy composites

0-3 PMN/ epoxy composites were prepared by the casting method. The effect s of piezoelect ric ceramiclead magnesium niobate2lead zirconate2lead titanate ( PMN) on curing of epoxy resin were studied by DSC analysis.The researches on dielect ric properties show that the dielect ric constant and dielect ric loss increase nonlinearly with PMN content increasing. The dielect ric constant decreases sharply with f requency increasing when the f requency is 5lower than 10 Hz , which is at t ributed to the interfacial polarization in the composite. At high f requency , the dielec2 tric constant changes slightly , which means that the PMN/ EP composites have a good high f requency stability. In the testing f requency range , the dielect ric loss decreases slightly with the f requency increasing , but the extent is very narrow. DMA analyses indicate that the storage modulus , loss modulus , the peak of the damping loss factor curve and the damping temperature range of composites are all affected by the content of PMN. When the PMN content was 87. 24 wt % , a new peak in the damping loss factor curve at about 90℃was observed , and the temperature of the new peak did not shif t with the testing f requency change. The dielect ric loss of composite may cont ribute to ap-pearance of the new damping loss factor peak.