| With the development of science and technology,more and more electronic and electrical equipment are used.The surface coating of some instruments not only needs to ensure good anti-corrosion performance,but also needs to discharge the excess charge on the surface of the instrument,so a single performance coating is difficult to meet.The use requirements of the instrument.In response to the above problems,this article has studied and prepared an electromagnetic shielding anticorrosive coating to meet the various requirements of equipment and instruments.Epoxy resin has excellent corrosion resistance and bonding properties,and is widely used in the fields of coating substrates,adhesives and engineering materials.Carbon nanotubes(CNT)have excellent electrical and mechanical properties and are ideal modified fillers for polymers.This thesis chooses epoxy resin E-51 as the coating substrate,but E-51 is relatively brittle,and micropores will appear due to the volatilization of the solvent during curing.Eucommia Ulmoides gum(EUG)is an isomer of natural rubber It has a unique chemical composition and rubber-plastic duality.It has excellent mechanical properties,corrosion resistance and wear resistance.Use EUG and CNT to modify E-51.An electromagnetic shielding anticorrosive coating with E-51 and EUG as the matrix and CNT as the modified filler is prepared,which improves the comprehensive performance of the coating and can meet the various requirements of the coating.First,surface active agent Triton is used to treat CNT,which can make the dispersion of CNT in the matrix more uniform.The effect of CNT as conductive fillers on the electrical conductivity and mechanical properties of E-51/CNT coatings was studied.It is determined that the optimal addition amount of CNT is 7wt%.Then,keeping the optimal addition amount of CNT unchanged at 7wt%,the matrix E-51 was modified with EUG,and the EUG/E-51/CNT composite coating was prepared by changing the ratio of EUG and E-51.The influence of the introduction of EUG on various properties of EUG/E-51/CNT composite coatings is analyzed.The thermal performance of the EUG/E-51/CNT composite coating was characterized.Both DSC and DMA results showed that the glass transition temperature(T_g)moved towards low temperature,the two have good compatibility.The electrical performance test of EUG/E-51/CNT composite coating shows that introducing EUG into the matrix can improve the conductivity and electromagnetic shielding performance of the coating.The surface morphology of the EUG/E-51/CNT composite coating was observed by SEM and found that the introduction of EUG not only improved the dispersion of CNT,but also made up for the micropores generated during E-51 curing.The mechanical properties of EUG/E-51/CNT composite coatings were tested,which showed that the introduction of EUG can improve the adhesion of the coatings.The anti-corrosion performance test of EUG/E-51/CNT composite coating shows that the introduction of EUG can improve the anti-corrosion performance of EUG/E-51/CNT composite coating.Epoxidized Eucommia Ulmoides gum(EEUG)is prepared by epoxidation modification of EUG.After EUG epoxidation,part of the internal crystals are destroyed,showing high elasticity and good toughness at room temperature.Compared with EUG,the polarity of EEUG increases and its corrosion resistance is enhanced,and the mechanical properties of EEUG are also better than EUG.Keeping the optimal addition amount of CNT unchanged at7wt%,the substrate E-51 was modified by EEUG,and the EEUG/E-51/CNT composite coating was prepared by changing the ratio of EEUG and E-51.The influence of the introduction of EEUG on the performance of the EEUG/E-51/CNT composite coating was studied,and the EEUG/E-51/CNT composite coating and the EUG/E-51/CNT composite coating were compared.The results show that EEUG and E-51 can undergo a co-curing reaction,and the compatibility of EEUG and E-51 is better than that of EUG and E-51.Compared with the EUG/E-51/CNT composite coating,the conductivity and EMI SE have a improvement.The introduction of EEUG not only improves the dispersion of CNT but also compensates for the micropores produced by E-51 during the curing process.The increase in adhesion of EEUG/E-51/CNT composite coating is also greater than that of EUG/E-51/CNT composite coating.The anti-corrosion test shows that the anti-corrosion performance of the EEUG/E-51/CNT composite coating is better than that of the EUG/E-51/CNT composite coating. |
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