Study On The Preparation And Performance Of Epoxy Resin Type Electrical Joint Compounded Grease

Electrical joint compounded grease is an important product used in electrical connections to reduce the resistance of the connection.It protects the connector from external corrosion and reduce the failure rate of power transmission.With the development of social economy,electricity consumption for residents and production is increasing rapidly.In power transmission,the cable connections become the weak links.Due to the small actual contact area of metal connections,electrochemical corrosion of the material,oxidation f or connection process and other reasons,overheating often occurs under the action of large current.In turn,the cable burns,causing economic losses and safety threats.The addition of the power compound grease and the correct use of the power compound grease can greatly reduce the resistance of the connection,and protect the metal conductor,reduce the failure rate,and ensure the normal residential electricity and industrial production.In order to improve the service life,safety and stability of the connector,it is very important to develop high-efficiency power compound grease.Therefore,the main research contents and results of this article are as follows.(1)Selection and performance test of power compound grease matrix.There are very few products used for connectors in the domestic market.There are only fewer types of conductive paste products and fewer types.It is mainly based on Vaseline,synthetic ester or lubricating oil as the base to add conductive fillers.During use,it is easy to be washed by rain,high temperature dripping,etc.After a long time of use,the matrix will be lost and invalidated,causing oxidation and electrochemical corrosion of the cable connection.In order to overcome these shortcomings,a curable epoxy resin system is selected as the matrix in this paper.Coated on the metal surface at room temperature,curing at room temperature or 80?100°C will not drop.Tests show that epoxy resin has salt water resistance and can effectively prevent electrochemical corrosion of metals.The epoxy resin has a strong bonding force to the metal surface,which can enhance the connector's grip on the cable.The epoxy resin and curing agent can effectively prevent matrix loss after cross-linking and curing.Tougheners and specific curing agents can reduce the brittleness of epoxy resins,making them more suitable for use in electrical connectors.(2)Preparation and characterization of silver nanowires with high aspect ratio.In the experiment,copper powder was used as a conductive filler,and it was found that it was difficult to form a conductive network in the resin.And it is easy to sink in the resin under the influence of gravity.There are many steps to modify the surface of copper powder.The copper powder is prone to oxidation during the modification process.Through searching literature,nano silver wire has good electrical conductivity.The article uses the alcohol reduction method,using PVP as the guiding agent and Cu Cl₂ as the controlling agent.Through the exploration of experimental conditions,at a reaction temperature of 150°C,the ratio of PVP to Ag NO₃is 2:1,the amount of Cu Cl₂ is 2‰,and the feed is stepwise.The concentration of Ag NO₃ is 0.06 mol/L.Under the above conditions,high-aspect-ratio silver nanowires with an average length of more than 30?m,a diameter of less than 100 nm,and an aspect ratio of more than 400 were prepared.(3)Test the physical and chemical properties and conductivity of the power composite grease prepared by the conductive grease.The prepared silver wire is mixed with epoxy resin,curing agent,a certain amount of diluent,and copper powder to prepare electric power compound grease,and electric power compound grease is prepared for volume resistivity test.Comparing the volume resistivity changes of conductive composites with different silver wire content from 2%to 10%,the percolation threshold of composite materials is obtained.When the amount of silver wire added is 5%,the volume resistivity of the compound grease decreases rapidly,reaching the percolation threshold of the material.When the length of the silver wire is 39.5?m and the mass fraction is 10%,the resistivity drops to 1.4?·cm,and the conductivity is excellent.The tensile and shear force of the composite grease was tested,and it was found that when the amount of silver wire added was 5%,the adhesion to the metal was average.Use a silane coupling agent to mix and modify the power composite grease,n-octyltriethoxysilane.The shear force of n-octyltriethoxy silane on the power composite grease is improved the most,reaching 11.3 MPa,which is an increase of 769% compared with not adding a silane coupling agent.