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

Abstract 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.