茂金属聚乙烯改性低密度聚乙烯介电性能与机械强度-电力设备电气.PDF

2007 5 Vol.22 No.5 22 5 TRANSACTIONS OF CHINA ELECTROTECHNICAL SOCIETY May 2007 710049 MPE LDPE PEA MPE 1wt% TM215.1 Dielectric Properties and Mechanical Strength in Low-Density Polyethylene Modified by Metallocene Catalyzed Polyethylene Wang Xia He Huaqin Tu Demin Mao Zhaoyuan Xi’an Jiaotong University Xi’an 710049 China Abstract In order to increase the electrical breakdown strength and mechanical properties of polyethylene insulated power cable, a small amount of metallocene catalyzed polyethylene (MPE) is blended into low-density polyethylene (LDPE) in this paper. Then, the remnant space charges in the blends after pre-stressed and then short-circuit is measured by pulsed electro-acoustic (PEA) method. At the same time the volume resistivity, DC breakdown strength, breakdown voltage of opposite- polarity after DC pre-stress and mechanical strength in the blends are studied in detail. The test results show LDPE blended with 1 wt% MPE can effectively improve its breakdown strength and mechanical strength but reduce the volume resistivity and tenacity. It is also indicated that the dielectric property and mechanical strength in polyethylene are in close relation to its crystalline morphology. Keywords Modified polyethylene, MPE, dielectric properties, mechanical strength [9] 1 [3] ,