Study On Morphology Structure And Interface Interaction Of EPDM/MVQ Blend

Silicone rubber has excellent high and low temperature resistance,weather resistance and electrical insulation,and is widely used in the automotive industry,aerospace and medical equipment fields.However,silicone rubber has the relatively high cost and the low mechanical strength,which limit its wide application in more fields.Ethylene propylene diene monomer(EPDM)has the advantages of high mechanical strength,good aging resistance,good weather resistance and low cost,but its high temperature resistance is not good.Therefore,the blend of EPDM and methyl vinyl silicone rubber(MVQ)is a good method to get a rubber material with high mechanical strength and high temperature resistance.However,the compatibility of EPDM and MVQ is relatively poor.The microscopic morphology of the blend(including the morphology of the dispersed phase,degree of dispersion,phase domain size)and interface compatibility have a very important impact on the macroscopic performance of the blend.In this thesis,EPDM/MVQ blend was prepared by an open roll mill,and the microscopic morphological structure and interface interaction were studied.The viscoelasticity and morphology of EPDM/MVQ blends(EPDM/v-MVQ materials)varied with the mixed ratio and temperature.In terms of viscoelasticity,as the amount of MVQ increased,the system's elasticity,viscosity and pseudoplasticity increased.When the group distribution ratio was EPDM/MVQ = 70/30,the flow behavior of the system was close to the ideal viscoelastic behavior.In addition,as the temperature increased,the viscosity of the system decreased and processing fluidity became better.In terms of morphological structure,when the EPDM content(mass fraction)was 30% and 70%,the system was a transitional structure.When the EPDM content was 40% to 60%,the system was a two-phase continuous structure.When the EPDM content is lower than 30% or higher than 70%,the system was a single-phase continuous structure.In addition,the prediction of morphological structure by dynamic rheological test was applicable to EPDM/MVQ-TPO materials.When the temperature rose to 160?,the system would undergo phase separation.The mixing temperature should not exceed 160?.The viscoelasticity and morphology of EPDM/MVQ selective vulcanization materials(EPDM/v-MVQ materials)(EPDM/MVQ = 70/30)were mainly influenced by the cross-linked MVQ phase,uncross-linked EPDM phase and inter-phase cross-linking.As the increase of the amount of crosslinking agent,the structure of MVQ crosslinked particles was more perfect and the size was increased.At the same time,the cross-linking effect between the phases gradually increased.In addition,the prediction of morphological structure by dynamic rheological test was applicable to EPDM/v-MVQ materials.Adding EPDM grafted with maleic anhydride(EPDM-g-MAH)and ?-aminopropyltriethoxysilane(KH550)to EPDM and MVQ could make EPDM/MVQ blend reactive compatibilization,which improved the microstructure and macroscopic properties of the blend.The effect of interfacial compatibility on the microstructure and macroscopic properties of EPDM/MVQ blend was studied by using infrared spectroscopy,torque rheological analysis,dynamic rheological test,static vulcanization performance test,dynamic mechanical performance test,cross-sectional morphology observation,energy spectrum analysis and mechanical performance test.