材料期刊网

采用平行双螺杆挤出机和转矩流变仪制备了SiO2/LDPE纳米复合材料，研究了两种工艺对纳米粒子分散情况和介电性能的影响。利用电声脉冲法（PEA）比较LDPE和SiO2/LDPE纳米复合材料的空间电荷抑制能力，并测量了其室温下的直流击穿特性。结果表明：SiO2/LDPE比LDPE具有更高的空间电荷抑制能力，且两种工艺制备的SiO2/LDPE直流击穿强度分别提高了21.8%和3%。扫描电镜（SEM）分析表明，平行双螺杆制备的SiO2/LDPE纳米复合材料中的纳米粒子分散性更好，其空间电荷的抑制能力更高，直流击穿强度比转矩流变仪制备的材料高18.22%。平行双螺杆比转矩流变仪具有较高的剪切力，可提高纳米粒子在聚合物中分散性，进一步提高了SiO2/LDPE纳米复合材料的介电性能。

SiO2/LDPE nanocomposites were prepared by parallel twin-screw extruder and torque rheometer, and the effect of two processes on the dispersion of nanoparticles and dielectric property was studied. The space charge suppression of LDPE and SiO2/LDPE nanocomposites was compared by pulse elec-tro-acoustic method (PEA), and the DC breakdown characteristics were measured at room temperature. The results show that the SiO2/LDPE has higher space charge suppression than that of LDPE. The DC breakdown strength of SiO2/LDPE prepared by the two processes increases 21.8% and 3%, respectively. According to the SEM observation results, the SiO2/LDPE nanocomposites prepared by twin-screw shows better dispersity of nanoparticles and higher space charge suppression, and its DC breakdown strength is 18.22% higher than that of the SiO2/LDPE nanocomposites prepared by torque rheometer. The parallel twin-screw has higher shearing force than torque rheometer. It can effectively improve the dispersity of nanoparticles in polymer, and further improve the dielectric property of the SiO2/LDPE nanocomposite.