Investigation On Breakdown Properties Of Low-density Polyethylene/Nano-ZnO Composites

As polyethylene is a thermoplastic resin which has the good comprehensiveperformance, But PE itself has some defects and insufficiency. The insulationperformance of PE will declined under high voltage for a long time. In order toimprove PE insulation performance, many scholars begin to pay attention to theinfluence of nano additives on electrical properties of PE. A number of studieshave suggested that compounding PE with nano-ZnO particles intonanocomposites can increase the electrical performance.This article based on LDPE for matrix resin, nano-ZnO which were used asinorganic filler, selection of silane coupling agent(KH-570) and titanium acidester coupling agent (105,101, TC-F) as modifiers. LDPE/ZnO composites wereprepared by melting blending method. Through the breakdown performance testare emphatically discussed different particle size, different preparation methods,different surface modification of ZnO, different content and different temperatureon the influence of the nanocomposite. Through the conductivity test ofcomposite material which was used to analysis the different content and differenttemperature on the influence of the composite materials. At last compositematerial was detected through dielectric spectrum test. Acoustic pulse method isused for the measurement of space charge.The results of breakdown test show that organic zinc oxide can increase thebreakdown strength of polyethylene/zinc oxide nanocomposites. Among of themby silane coupling agent(KH-570) surface modification to improve the most. Wecan know that the smaller size of nano-ZnO can better integration with matrixresin, when the content of nano-ZnO was3%, its breakdown field strength higherthan pure LDPE11%. The right content of organic zinc oxide can effectivelyslow down the magnitude of breakdown field strength with increasingtemperature. The conductivity test result show that the conductivity of the composites were increased with the montmorillonite filled, but the right contentof organic zinc oxide can effectively slow down the magnitude of its conductivityincreases with increasing temperature. Dielectric spectrum tests show that nano-make composite dielectric constant reduce, loss tangent value increase. Asfrequency increase different contents of composite material conductivity show arising trend. The PEA spectrum indicates that nano-ZnO composite internal spacecharge can achieve stable state in short time. During the process of short circuit,the space charge can be effectively discharged.