中文摘要：

选用纳米Al_2O_3粒子作为填料,通过熔融共混法制备出不同填料质量分数（0.1%、0.2%、0.5%、1%）的低密度聚乙烯纳米复合材料。利用电声脉冲法研究了室温下纳米复合材料在30k V/mm场强中空间电荷分布及场强畸变特性,并测量了固定场强中不同温度下的直流电导率和室温下不同场强中材料的电导率变化。结果表明,当纳米粒子添加量为1%时,能有效改善聚乙烯中电荷积聚和场强的畸变现象,并降低聚乙烯的直流电导率。同时发现不同场强下,不同含量的聚乙烯纳米复合材料的直流电导率,随温度变化趋势不同。

英文摘要：

Low-density polyethylene （LDPE） nano- composites filled with alumina nanoparticles （nano-A1203） with mass fraction of 0.1%, 0.2%, 0.5% and !% were prepared employing the melting blend method. Space charge profiles and electric field distortion characteristics of LDPE nanocomposites under the electric field of 30 kV/mm at room temperature were measured by the pulse electro-acoustic method. Effects of temperature and electric fields on direct current （DC） conductivity of the nanocomposites were also studied. Results show that 1% A1203 nanoparticles added into LDPE can effectively improve the charge accumulation and field distortion in the LDPE nanocomposites and reduce DC conductivity. Moreover, the DC conductivities of LDPE nanocomposites have different temperature trends under different electric fields.