Effect of SIS block copolymers on damping properties of natural rubber/AO-80 and the performance enhancement mechanism: experimental study and molecular dynamics simulation

Natural rubber/blocked phenol/styrene-isoprene block copolymer (NR/AO-80/SIS) composites were prepared by using hindered phenolic polar small molecules (AO-80) and styrene isoprene block copolymer (SIS) as damping performance-enhancing components and (NR) as rubber substrate to overcome the problems of narrow effective damping temperature range, unsatisfactory damping effect and subpar mechanical properties in NR/AO-80 rubber applications.The effects of SIS and AO-80 on the morphology, structure, mechanical properties, aging resistance, and damping properties of the NR/AO-80/SIS composite were investigated. Molecular dynamics simulations (MD) were employed to investigate the intermolecular forces, and interaction mechanisms of the rubber composites. SIS exhibited compatibility with the NR/AO-80 matrix and can significantly enhanced the mechanical, aging, and damping properties of the NR/AO-80 matrix. The effective damping temperature range can be extended to a maximum of 114.5 °C, demonstrating its notable improvement to the damping performance of NR/AO-80. The primary mechanisms of enhancing damping performance involve the more van der Waals forces, electrostatic interactions in NR/AO-80/SIS composites,which is beneficial for increasing the internal friction of rubber and improving the damping performance of NR/AO-80 /SIS.