| The blends of ethylene-propylene diene copolymer (EPDM) and acrylate rubber (ACM) have been prepared. Then the compatibility, processability, curing system, reinforcement system and heat aging properties of the blends have been investigated.Firstly, the compatibility and effects of compatibilizers on blends were studied by various techniques. Theoretical calculations showed that the blends were not compatible thermodynamic system. FTIR spectra and DSC indicated that there were some certain compatibility between the two rubbers. Thermo-gravimetric analysis and physical property testing showed that thermal stability, tensile strength, tear strength and abrasion performance improved, while heat oxygen aging performance fell with the increase of blend ratio of EPDM/ACM blends. FTIR and DSC also indicated that there were some interaction between compatibilizers and the blends. It was proved that the best properties were achieved when adding15phr AEM or20phr EPDM-g-MAH.Secondly, effects of different curing systems on the properties of EPDM/ACM blends were studied and the best curing system was determined. Besides, orthogonal design method were adopted thus the best formula was found out. The results showed that the blend cured by DCP/TCY curing system had suitable optimum cure time and proper crosslinking density. Tensile strength of the vulcanizates was17.2MPa, tear strength was38.5N·mm-1and compression set was30.6%when cured by DCP/TCY curing system. Orthogonal design experiment showed that the optimal formula of vulcanization system was DCP3phr, TCY2phr, S0.3phr, DM0.5phr and ZnO5phr.Futher more, properties of EPDM/ACM blends filled with various carbon blacks were investigated. The results showed that the more loading and the smaller carbon black particle size in compounds, the more obvious Payne effect appeared. Small particle size was favorable for reinforcement but not conducive to decentralization or processing. Carbon blacks with large particle size would lead to the prolongation of cure time. Good comprehensive performance was achieved when carbon blacks N330N550or CD2109was added. Along with the increase of carbon black N330, the Mooney viscosity, curing torque, hardness and abrasion resistance of the blends increased, while curing time, scorch time, tensile elongation and resilience decreased. It was proved that the highest tensile strength was achieved as16.2MPa with60phr N330and the best tear strength was obtained as36.9N·mm-1when the content changed to80phr.Finally, heat aging properties of EPDM、ACM and the blends were studied. FTIR indicated that oxygen structure of EPDM after aging was formed via consumption of methyl and the surface oxidation degradation of ACM tended to react on the methylene carbon of main chain. Chain scission was occurred primarily at upfront aging time and the late was given priority to crosslinking. Stereoscopic microscope, SEM and physical properties showed that blending with ACM could obviously improve the aging resistance of EPDM. |
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