Preparation and mechanical properties of water-dispersible hyperbranched polymer grafted carbon black/natural rubber composites by latex blending method

In order to improve the mechanical properties of rubber-matrix composites, carboxyl-terminated hyperbranched poly (2-hydroxypropane-1,2,3-tricarboxylic acid) grafted carbon black (CB-g-CTHBP) was prepared, and it could be stably dispersed in water for up to 90 days. CB-g-CTHBP dispersion and natural rubber latex were blended to obtain NR/CB-g-CTHBP, and the effect of CB-g-CTHBP content on the mechanical properties of composites was discussed. The results show that the dispersibility and wettability of CB-g-CTHBP to composites are significantly improved after grafting hyperbranched polymer onto the surface. Compared with the composite filled with NR/CB, when the amount of filler is 30 phr, tensile strength, tear strength, and shore A hardness of NR/CB-g-CTHBP increase by 54.78%, 55.13%, and 20.96%, respectively. Moreover, CB-g-CTHBP could disperse more evenly in the natural rubber-matrix, and the interaction between CB-g-CTHBP and rubber-matrix could further enhance in the composite.