Study On The Effect Of Additives On The Trap Characteristics Of Silicone Rubber Materials

With the increase of operating years of composite insulators,the ageing problem of silicon rubber is becoming increasingly serious.The trap characteristics of silicon rubber materials have a certain relationship with its ageing characteristics.Therefore,it is meaningful to study the trap characteristics of silicone rubber materials.Silicone rubber materials contain various additives.The research shows that additive has an important effect on the structure and properties of silicone rubber.The addition of additives in silicone rubber will have a certain effect on the characteristics of the trap.So attenuation curve of surface charge of silicone rubber is tested by isothermal surface attenuation method.The influence of additives on the deep and shallow trap characteristics of silicone rubber is analyzed by using double trap level model.It has been shown that the addition of micrometer aluminum hydroxide to silicon rubber produces shallow trap effect.Because of percolation,when 190phr's aluminum hydroxide is added to the silicone rubber,the trap energy level is deepened.In this paper,when silicon rubber is added with the aluminum hydroxide of 130phr,the most shallow traps are introduced.The addition of nanometer silica in silicone rubber will result in a large number of deep traps due to the strong electrostatic force of the interface.Under the corona ageing,the change of the trap characteristics of the silicone rubber materials with different additives is different.For ATH/silicon rubber material,the corona reduces the crosslinking density of the material,forms a physical defect and increases the shallow trap in the material.SiO2/silicon rubber will produce chemical bonds under the effect of corona ageing.The crosslinking density is increased and a large number of deep traps are produced.Under the effect of UV ageing,the change of the trap characteristics of the silicone rubber materials with different additives is also different.With the increase of UV ageing time,shallow traps are introduced in ATH/silicone rubber,then deep traps are introduced.The change of the trap characteristics of SiO2/silicone rubber material under the UV ageing effect is influenced by the content of the additive SiO2.When 40phr silica is added to silica rubber,the deep traps will be introduced into the material by UV ageing.When adding 60phr silica,the material will produce shallow traps by UV ageing.