High-Performance Nitrile Butadiene Rubber Composites with Good Mechanical Properties, Tunable Elasticity, and Robust Shape Memory Behaviors

Considering technical requirements in the oil industry, the reinforcement of nitrile butadiene rubber (NBR) becomes an important issue. In this article, dual cross-linking networks, composed of covalent and sacrificial metal-ligand bonds, were constructed in a ready-made NBR matrix. The presence of Zn2+-CN coordination bonds dissipated energy to simultaneously improve the tensile strength, modulus, and elongation at break of NBR composites in contrast to neat rubber. The elasticity and glassy temperatures of NBR composites were easily tunable by dual cross-linking network architectures. Moreover, NBR composites possessed good oil-resistance property, displaying an extremely low swelling degree when they were soaked in oil at 70 degrees C for 72 h. More strikingly, as-prepared NBR composites showed thermally triggered shape memory behaviors, which had a high shape fixing ratio and shape recovery ratio in air and oil. Therefore, we believe that NBR composites having dual cross-linking networks may expand the mechanical and shape memory applications to face complex environments.