The design of crosslinks in different vulcanized systems to improve crack growth resistance for carbon black/graphene oxide/natural rubber composites

Herein, the carbon black/graphene oxide/natural rubber composites (CB/GO/NR) with different crosslink networks were prepared through the latex co-precipitation approach. Meanwhile, the type of crosslinks on the crack propagation resistance and fatigue life in different vulcanized systems was investigated. As a result, CB/GO/NR composites dominated by polysulfide in the conventional vulcanization (CV) system exhibited the highest tear strength (71.6 kN/m) and lowest crack growth rate (64.1 nm/cycle), the crosslink network and polysulfide-based crosslink structure in the CV system were the key factors to improve the crack propagation resistance. In addition, the relationship between viscoelasticity and dynamic crack propagation behavior of CB/GO/NR is studied, and the CV system had the lowest loss compliance modulus (J″ = 0.0014 Mpa−1), thus more energy dissipation occurred in the crack propagation region and the crack propagation resistance of CV system was improved. Importantly, this work can provide the guideline for designing the rubber-based composites in the practical engineering applications.