Preparation Of MgO/Polyolefin Insulation Nanocomposites And Study Of Electrical Properties

With the increase improvement of technology, the safe operation ofpower system is more and more important. Insulation material is oneimportant part of the power system. The properties are critical to thesuccess function of power system. The industry requires insulationmaterial with high breakdown strength and other good performance.Polymer is a kind of commercialized insulation material. It plays animportant role in the power system because of its excellent electricalinsulation properties, thermal stability, mechanical properties, light weightand cheap price, etc. However, polymers still cannot meet the requirementsin some electrical field with critical standards due to its own shortcomings.Therefore, it is very important to improve the electrical performance ofpolymers by chemical or physical methods. Nanoparticles are outstandingpolymer modifier. Nanoparticles make polymers show properties differentfrom the matrix itself because of the large specific surface and nano-effect. It is a high effective way to modify polymers.Nano magnesium oxide (MgO) particles are utilized to modifypolyethylene and polypropylene. Good dispersion of nanoparticles in thepolymer is achieved by mechanical blending. Cross-linked polyethylene(XLPE) with MgO at the content of1wt%and pure XLPE are studiedcomparatively. The results show that nanoparticles can significantlyincrease the DC and AC breakdown strength, thermal stability and tensilestrength of XLPE. Space charges are suppressed and DC voltageendurance lifetime keeps good. Polypropylene nanocomposites with MgOat different content are studied comparatively. The DC breakdown strengthof the material increased at low MgO content and then decreased at higherMgO content. Nano-MgO particles can suppress space charge in thematerial. Nano-MgO particles can promote the generation of β-polymorphof polypropylene. It proves to be a nucleating agent of β-polymorph.