▎ 摘　　要

Crack resistance of rubbers is of vital importance in many applications (e.g., tire and shock absorber). In this work, we demonstrate the crack resistance improvement and toughening of natural rubber-solution polymerized butadiene styrene rubber (NR-SSBR) blend by designing a filler network composed of graphene (GE). The well-dispersed GE nanosheets contact with each other and bridge the adjacent GE nanosheets based on the pi-pi conjugation interaction, which preferentially break upon deformation and dissipate energy before the failure of the materials. The mechanisms of energy dissipation under small and large strains were further discussed. The approach of crack-tip morphology monitoring was also applied to understand the crack resistance behavior of the rubber material. The GE network and its energy dissipation not only increase the tensile strength and toughness, but also enhance the crack resistance of the NR-SSBR by expanding the tear energy region of high cracking energy dissipation. Improvement on these properties will provide the rubber blend with better long-term sustainability in practical applications. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47278.