▎ 摘　　要

Natural rubber (NR) composites containing graphene (GE) are prepared by ultrasound-assisted latex mixing and in situ reduction. The fatigue crack propagation of the composite is examined. It is observed that GE has an opposite effect on crack growth resistance of NR, i.e., at lower fatigue strains, the inclusion of GE accelerates the crack growth, whereas at higher strains, the crack growth is retarded. It is suggested that the reason for this behavior is a competition between strain-induced crystallization and cavitation at crack tip. Through microfocus hard-X-ray diffraction beamline with high spatial resolution, fatigue crack resistance is correlated to strain-induced crystallization and new insights into the mechanism of fatigue crack growth are obtained.