活性氧化铝改性纳迪克酰亚胺的性能研究

Properties of nadic polyimide modified by gel-alumina

利用溶胶-凝胶技术制备了纳米氧化铝改性纳迪克酰亚胺复合材料。采用傅里叶红外光谱（FTIR）、扫描电镜（SEM）和原子力显微镜（AFM）等手段对该材料的结构及表面断裂形貌进行了表征，其粒子尺寸为40～100nm。研究了氧化铝添加量对该复合材料耐电晕性能和耐热性能的影响。结果表明：随着氧化铝含量的增加，材料的耐电晕性能显著增强，当纳米氧化铝质量分数为16％、试样厚度25μm、击穿场强60kV／mm时，耐电晕寿命达130h，是改性前的11倍；热分解温度为498．63℃，比掺杂前提高20℃，剪切强度略有降低。

The in-situ sol -gel method was employed to prepare nano-alumina/PI hybrid composite. The chemical structure, morphology, the corona-resistant lifespan and thermal property were characterized by the method of Fourier transform infrared spectroscopy （FTIR）, atomic force microscope （AFM）, scan electric microscope （SEM） and thermogravimetric analysis （TGA）. The micrographs of AFM and SEM indicate that nano-alumina particles are finely dispersed in the polymer resin. The sizes of alumina particles are 40-100 nm. The solid content of nanoalumina influences the corona-resistant lifespan and thermal-resistance. The corona resistant lifespan and thermal decomposition temperature are increased with increasing the solid content. When the mass fraction of nano-alumina is 16% Al2O3/PI, the width of sample is 25μm and breakdown strength is 60 kV/mm, its corona-resistant lifespan is 130 h, rising 11 times, its thermal decomposition temperature is 498.63℃, rising 20℃, and the shear strength is a little lower than that of the pure material.