Effect of the ratio of carbon nanotubes and carbon black on the properties of natural rubber

In this experiment, the effect of carbon nanotubes (CNTs) replacing some carbon black (CB) on the properties of natural rubber composites was investigated. 5 phr of CNTs were used to replace part of CB in the ratio of m(CNTs) : m(CB reduction) = 1 : X (X from 1 to 4.5). The properties of the vulcanized rubber such as vulcanization, thermal conductivity, tensile, heat generation and processing were investigated experimentally. The results showed that when the ratio of CNTs/CB(reduction) was 1:1, it could substantially improve the crosslink density of the sample and reduce the vulcanization time, while having better processing safety and having the best thermal conductivity. At this time, 5 phr of CNTs and 40 phr of CB were added to the sample, and the dispersion of CB and CNTs in the sample was studied by CB dispersion tester and rubber processing analyzer. The tensile property change regularity tested by rubber tensile tester matched with the experimental results of CB dispersion tester and rubber processing analyzer. When the ratio of CNTs/CB(reduction) was 1:1, it increased the heat generation of the sample significantly. When the ratio of CNTs/CB(reduction) was 1:3.5, all the properties of the sample were better than those of the 1# sample.