Aging Characteristics Of Nano Zeolite/Low Density Polyethylene Composites

With the development of modern power transmission,the insulation performance requirements of high-voltage transmission cables have gradually increased.At the same time,ordinary polymer materials have been unable to meet the needs of future power transmission development.Therefore,the nano-modification technology of polymers has begun to receive attention.It opens up a new direction for the research and development of new materials and the modification and improvement of existing materials.With reference to the status quo of nanoscience,the future research direction of nano-dielectric materials can consider the use of nanoparticles with some special microstructures or special properties,that is,using the various characteristics of the nanoparticles themselves and the various special effects brought by the nanoscale.The insulating material is modified.According to existing research,it has been found that doping with inorganic nanoparticles with a porous structure can increase the breakdown voltage of polyethylene and effectively suppress space charge.Based on this,this paper uses thermal aging experiments,electrical tree experiments and related physical and chemical performance tests to detect the changes in the properties of low-density polyethylene doped nano-zeolite particles after thermal aging,and combines interface effects,electrical double layer theory and multi-core Models and other principles analyze and explain experimental phenomena.The main tasks are as follows:(1)The processed Na Y and 4A zeolite nanoparticles are melt blended with low-density polyethylene(LDPE)to prepare composite samples according to the set concentration;the dielectric properties of the zeolite/LDPE composite The constant and dielectric loss first decrease and then increase with the doping concentration.Compared with pure LDPE,the dielectric constant and dielectric loss change much smaller before and after thermal aging.(2)The physical and chemical properties and macro-dielectric properties of the material were tested,and it was found that Na Y and 4A zeolite/LDPE composite materials have certain thermal aging resistance,and the Na Y doping mass fraction is1wt%,and the 4A doping mass fraction is 0.5wt% When the composite material has the best thermal aging resistance.The pore structure of zeolite nanoparticles acts as a connection point,connecting the macromolecular chain of LDPE,reducing the mobility of the molecular chain,increasing the crystallinity of the composite material,and delaying the thermal aging process.(3)LDPE/Na Y type nano zeolite composite material and LDPE/4A type nano zeolite composite material both show obvious ability to inhibit the growth of electrical tree branches,and when the doping mass fraction is 0.5-1wt%,the inhibition effect is the best;The doping of zeolite particles changes the physical and chemical properties and macro-dielectric properties of the base material polyethylene such as the dielectric constant and crystallinity,and changes the growth form of the electrical tree branches.The tree shape develops into a cluster structure,which improves the internal field of the pattern.Strong,changes the path of electric tree growth,thereby inhibiting the growth of electric tree branches.