无增容少用量EPDM优化NR的力学性能和老化性能OA

Natural rubber(NR)/ethylene propylene diene monomer rubber(EPDM)composites were prepared using a non-augmentation system under conventional vulcanization,and the effects of small amounts of EPDM on the mechanical and aging properties of NR were investigated.The interfacial compatibility and dispersion of the composites were also characterized.The results showed that the mechanical properties of the composites were optimal when the mNR/mEPDM was 90/10,with a tensile strength of 20.5 MPa and a tear strength of 22.58 N/mm.The aging properties were best when the mNR/mEPDM was 85/15,with a tensile strength retention rate of 28%and an elongation at break retention rate of 70%.As the amount of EPDM increased,the overall integrity and uniformity of the composite's fracture surface improved.Structural discontinuities appeared when the mNR/mEPDM was 80/20,but the composites maintained structural continuity after aging treatment compared to pure NR.The composites with a small amount of EPDM had only one glass transition temperature,indicating good interfacial compatibility.Dynamic mechanical properties showed that the NR/EPDM composites exhibited the Payne effect,and when the mNR/mEPDM was 90/10,the tight interfacial bonding and optimal synergistic load-bearing of the molecular chains were achieved.