| Abundant of electronic equipments are used in weapon equipments. It will bring seriousconsequences that errors occur due to electromagnetic signal being vulnerably interferencedby external electromagnetism, which have aroused high attention to the protection of a varietyof electromagnetic hazards. Additional, shielding electromagnetic pollution and limiting it ina certain area, have become one of the hot topics in environmental protection. Because ofsuperior the ozone resistance, erosion resistance ability, excellent vulcanization characteristics,and the lowest density in all rubber, ethylene propylene diene monomer (EPDM) has beenwidely used. Advanced studies show that the mechanical properties and electromagneticperformances of EPDM could improved by adding some functional fillers, so that it couldwiden the application of EPDM rubber in the field of electromagnetic shielding, absorbing,conduction and sensing.In order to develop a kind of magnetic reinforcing EPDM rubber composite materialused for electromagnetic shielding, the dissertation is devoted to the research in themicrostructure and performance of EPDM rubber by combing the molecular simulationmethod and the experiments. As EPDM rubber as the matrix, the optimum dosage of carbonblack was obtained. Then EPDM rubber composite materials were prepared by addingdifferent reinforced particles. Fe/Ni alloy nanoparticle was prepared by hydrothermal method,and the properties were characterized. Then, the best formula of enhanced and magneticEPDM rubber was obtained.(1) The microstructure and performance of EPDM rubber were studied by moleculardynamics (MD) and mesodyn simulation method. The glass transition temperature is spinnedto216.3K by MD, and the refractive index, surface tension, thermal conductivity and bulkmodulus take a big change around the glass transition temperature. The radius of gyration of EPDM indicates that EPDM is in a shape of entanglement. Additional, the distribution of theradius of gyration mostly concentrates on18.9-19.3rather than other distances. Theflexibility, flexural, and entangle extent could be predicted by the radius of gyration of a givenpolymer. Finally, the effect of phases and morphologies of EPDM chains were simulated bymesodyn method.(2) As EPDM rubber as the matrix, the optimum dosage of carbon black was obtained.Then EPDM rubber composite materials were prepared by adding zinc methacrylate (ZDMA),calcium carbonate (CaCO3), montmorillonite (MMT), ZDMA/CaCO3and ZDMA/MMTrespectively, and the properties of rubber were tested. The influence of the mechanicalproperties and ageing-resistant performance were investigated by adding different contentsfiilers. When the additive amount of carbon: EPDM is55g:100g, the mechanical propertiesof the prepared vulcanized EPDM rubber achieves the best. When ZDMA together withCaCO3filled in100g EPDM rubber, the mechanical properties could be obviously increased,and the optimum content ratio is10g:40g. However, when the content of MMT/ZDMA are15g/5g, the mechanical properties achieved the best. The tensile strength is20.12MPa, theelongation at break is1734.76%, and shear strength is57.79kN/m.(3) Fe/Ni alloy nanoparticle was prepared by hydrothermal method, and which wasmodified by silicane coupling agents. Fe/Ni alloy nanoparticles disperse uniformity exhibitingsnowflake, and the coercivity is118.6Oe. The mechanical properties are improved by addingthe Fe/Ni nanoparticle modified by silicane coupling agents. The comprehensive mechanicalproperties of EPDM vulcanized rubber are the best by adding25g modified Fe/Ninanoparticle. Moreover, the filled EPDM rubber has good corrosion resisting properties inacid or alkali solution, and little quality change. The saturation magnetization (Ms) andremanent magnetization (Mr) of the magnetic rubber are gradually increased by the additiveamount of the magnetic particles, and the Ms and Mr achieve the maximum (13.54and8.44emu/g) by adding25g modified Fe/Ni alloy nanoparticle. |
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