一种纳米二氧化硅/低密度聚乙烯复合材料及其制备方法，该复合材料是由低密度聚乙烯、改性纳米二氧化硅和抗氧剂组成，其中改性纳米二氧化硅占复合材料的比重是0.5 wt%、抗氧剂占复合材料的比重是0.3 wt%。其制备方法是：将低密度聚乙烯、改性纳米二氧化硅和抗氧剂加入到混炼机中，在120 ℃~150 ℃温度下熔融共混，即得复合材料。含有少量改性纳米二氧化硅的低密度聚乙烯复合材料表现出对空间电荷很好的抑制能力，其交直流击穿场强、结晶度均比纯低密度聚乙烯有较大提高，其电导率较纯低密度聚乙烯明显降低。
A nano-silica/low density polyethylene composite material and its preparation method are composed of low density polyethylene, modified nano-silica and antioxidant. The proportion of modified nano-silica in the composite material is 0.5 wt%, and that of antioxidant in the composite material is 0.3 wt%. The preparation method is as follows: low density polyethylene, modified nano-silica and antioxidant are added to the mixer, and melted and blended at 120 ~150 ~C to obtain the composite material. Low density polyethylene (LDPE) composites containing a small amount of modified nano-silica exhibit good space charge suppression ability. Its AC and DC breakdown field strength and crystallinity are higher than those of pure LDPE, and its conductivity is significantly lower than that of pure LDPE.