中文摘要：

为了降低低密度聚乙烯中的空间电荷积累,在自制纳米MgO粉体的基础上,采用熔融共混法,制备了氧化镁/低密度聚乙烯（MgO/LDPE）纳米复合材料,并通过扫描电镜（SEM）观察了MgO/LDPE纳米复合材料中的MgO粒径大小和分散情况,采用差热扫描量热法（DSC）确定了不同MgO质量分数纳米复合材料的结晶度,采用电声脉冲法（PEA）测量了不同MgO质量分数纳米复合材料的空间电荷分布,测量了不同MgO质量分数纳米复合材料的拉伸性能。试验结果表明,MgO/LDPE纳米复合材料体系中,MgO粒径约为50nm,且分散均匀;不同MgO质量分数纳米复合材料的弹性模量和抗张强度均高于纯LDPE的,且MgO质量分数为2%时达到最大值;不同MgO质量分数纳米复合材料的结晶度均高于纯LDPE的;纳米MgO能抑制空间电荷的注入和其在材料体内的迁移,质量分数为3%时,MgO/LDPE纳米复合材料中的空间电荷得到了良好的抑制。

英文摘要：

To decrease the accumulation of space charge in low density polyethylene（LDPE）,we prepared magnesium oxide（MgO）/ LDPE nanocomposites by mixing melted LDPE and MgO nano-powder.The dispersion and particle size of MgO in MgO/LDPE nanocomposites were characterized by scanning electron microscope（SEM）,the crystallinity of MgO/LDPE nanocomposites with different contents of MgO was determined by using differential scanning calorimetry（DSC）,the space charge distribution of MgO/LDPE nanocomposites with different content of MgO was measured by using pulse electro-acoustic（PEA）,and the tensile properties were measured.The experimental results reveal MgO particles with diameters of about 50 nm are well dispersed in MgO/LDPE nanocomposites.The elastic modulus and tensile strength of LDPE/MgO nanocomposites with different content of MgO are higher than those of pure LDPE,and reach the maximum at the MgO loading of 2%.The crystallinity of MgO/LDPE nanocomposites with different contents of MgO is higher than that of pure LDPE.The space charge injection and mobility of MgO/LDPE nanocomposite can be suppressed by nano MgO loading,and the space charge of MgO/LDPE nanocomposite is effectively suppressed at the MgO loading of 3%.