Study on the relation between composition, microstructure and performance of EPDM composites with high damping and resilience properties

Focusing on the balance between damping performance and resilience of ethylene-propylene-diene monomer (EPDM) rubber composites, this work mainly studied the influence of butyl rubber (IIR), carbon black (CB) content and CB types on the microstructure including chemical crosslinking and filler network, and properties of IIR/EPDM composites. The results showed that the increase in IIR content increased the molecule saturation degree, and the content of side methyl groups in the IIR/EPDM compound. The degree of entanglement of rubber molecular chains was also increased. IIR also increased the shearing modulus, and damping properties, but lowered the resilience of IIR/EPDM composites. Furthermore, the decrease in CB content and the introduction of CB with larger particle size in IIR/EPDM composites lowered the filler network, increased the filler dispersion of the composites, and the mobilities of rubber molecules, leading to high damping and resilience properties of IIR/EPDM composites. Therefore, when introducing a proper mass ratio of EPDM/butyl rubber (80/20), CB (N550) with large particle size, and less CB content (45 phr) in the EPDM composite, the composites with good damping performance and resilience were obtained.