Introducing metal-ligand coordination interaction for self-healing and recyclable nitrile–butadiene rubber: A facile strategy

Abstract

In this research, a nitrile-butadiene rubber (NBR) was prepared with excellent mechanical, self-healing and recycling properties by introducing metal-ligand coordination interaction. A coordination crosslinking network based on ligand bonding was successfully introduced in the NBR matrix by mechanical compounding. The dynamic reversibility of the coordination crosslinking network not only provides the vulcanizate with excellent mechanical properties but also confers a remarkable self-healing ability under high temperatures and recyclable property under mechanical shear, respectively. The sample, which was subjected to the complete cut, could be capable of restoring its original tensile strength after self-healing treatment. The self-healing efficiency of NBR vulcanizate is significantly dependent on the self-healing temperature and time, which can surprisingly reach 97% of the original tensile strength after self-healing treatment at 180 °C for 60 min. After the mechanical shear, the coordination crosslinking network is reversibly transformed. The tensile strength of the NBR vulcanizates after mechanical shearing recycling and re-vulcanization was similar to that of the original NBR vulcanizates. This research presents a novel approach to enhance the durability of rubber used in commercial applications, endowing it with reshaping and recycling capabilities and mitigating environmental issues associated with waste rubber.

Keywords

• rubber
• recycling
• mechanical properties
• self-healing
• coordination
• crosslinking
• self-healing
• recycling of rubbers
• devulcanization
• mechanical recycling
• stress relaxation