Application And Research Of Ethylene And Tetrafluoroethylene Polybasic Copolymer

Ethylene-tetrafluoroethylene copolymer coating is a fluorinated polymer material with superior properties,which has been widely used in aerospace,military special materials and pipeline lining.However,ETFE has certain problems in the field of heat conduction,such as low thermal conductivity,low heat dissipation efficiency,and very few solvents that can dissolve ETFE.In response to the above questions,this thesis studies the effect of different thermal conductive fillers on the thermal conductivity of ETFE,and uses ETFE materials as the polymer matrix.Graphite/ETFE composite coating,graphene/ETFE composite coating,carbon nanotube/ETFE composite coating,boron nitride/graphite/ETFE composite coating and boron nitride/graphene/ETFE were prepared by powder electrostatic spraying technology.Graphite/ETFE composite powder coatings with the graphite content of 0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8 wt.%and 1.0 wt.%were prepared by mechanical mixing method,using electrostatic spraying process to prepare powder coating as composite coating,and the adhesion,hardness,thermal conductivity and corrosion resistance of the coating were measured.The results show that the thermal conductivity of the composite coating increases continuously,in the range of 0⁰.7 wt.%of the graphite fillers mass fraction.The thermal conductivity of the ETFE coating was 0.10 W·m^-1·K^-1,the thermal conductivity was 0.21W·m^-1·K^-11 when the amount of graphite fillers was 0.7 wt.%,which is 110%higher than that of pure ETFE coating.The adhesion,hardness,acid and alkali resistance and mechanical properties of the composite coatings are well maintained.The composite graphite was more evenly distributed in the ETFE matrix,and the composite coating has excellent comprehensive properties.Graphene/ETFE composite coatings with the graphene content of 0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,1.0 wt.%and 2.0 wt.%were prepared by mechanical blending and powder electrostatic spraying.The the adhesion,hardness,thermal conductivity and corrosion resistance of the composite coatings were measured.The results show that the thermal conductivity of the composite coating increased continuously,with the increase of graphene fillers mass fraction.In the range of 0⁰.6 wt.%graphene filler content,the thermal conductivity of composite coatings keeps increasing,and the mechanical properties of composite coatings were excellent.In the range of 0.6².0 wt.%graphene filler content,the thermal conductivity of composite coatings will continue to increase.When graphene fillers content was 2.0 wt.%,the thermal conductivity increases to 0.38 W·m^-1·K^-1,but the mechanical properties will decrease and the adhesion becomes worse.Graphene/ETFE composite coatings with different layers of graphene mass fractions of0.3 wt.%and 0.6 wt.%were prepared by mechanical blending and powder electrostatic spraying.The thermal conductivity of the composite coating was measured.The results show that different layers of graphene have little effect on the thermal conductivity of the composite coating at the same mass fraction.Carbon nanotubes/ETFE composite coatings with the carbon nanotubes content of 0.1,0.3,0.4,0.5,0.6,0.7,0.8,0.9 wt.%and 1.0 wt.%were prepared by mechanical blending and powder electrostatic spraying,and the adhesion,thermal conductivity and corrosion resistance of the coating were measured.The results show that the thermal conductivity of the coating will not increase significantly with the increase of carbon nanotubes content,and which was stable in the range of 0.20⁰.22 W·m^-1·K^-1.The mechanical properties,corrosion resistance and adhesion of the coatings remain good.The composite carbon nanotubes are uniformly distributed in the ETFE matrix,and the formed heat conduction network was complete.The composite coatings have excellent comprehensive properties.The three different thermal conductive filler composite coatings were prepared,and the thermal conductivity of the three coatings was improved to varying degrees while their mechanical property were kept within a good range.Comparing the thermal conductivity of three different thermally conductive filler composite coatings,the results show that the carbon nanotubes had the best effect on improving the thermal conductivity of the coatings,when the content of thermally conductive fillers were less than 0.5 wt.%;the graphene fillers had better effect on improving the thermal conductivity of the coatings,when the content of thermal conductive fillers were morer than 0.5 wt.%.Aiming at the problems of graphite/ETFE composite coatings and graphene/ETFE composite coatings,boron nitride was added to the two kinds of composite coatings in proportion to prepare boron nitride/graphite/ETFE composite coating and boron nitride/graphene/ETFE composite coatings.and the thermal conductivity and mechanical properties of the composite coating were tested.The results show that the thermal conductivity of the coating obtained after the introduction of the boron nitride filler in the two composite coatings was improved.When the mass fraction of graphite was 0.7 wt.%and the mass ratio of boron nitride to graphite was 2:1,the thermal conductivity of the composite coating was 0.26 W·m^-1·K^-1,and the mass fraction of graphene was 0.5 wt.%and the mass ratio of boron nitride to grapheme was 2:1,the thermal conductivity of the composite coating was 0.25 W·m^-1·K^-1.In summary,the thermal conductive fillers were introduced into the ETFE coating to improve its thermal conductivity by mechanical blending and power electrostatic spraying.The thermal conductivity of ETFE coatings was improved by adding thermal conductive fillers in different systems,and the adhesion,hardness and corrosion resistance of ETFE coatings were kept within the standard range.The above experimental results show that thermal conductive polymer-based composite coatings have broad application prospects in the fields of chemical anti-corrosion and heat exchanger pipeline lining.