Study On Trg/Cnt/Silicon Rubber Electrically Conductive Composites

This paper studies the influence of technological conditions on graphene morphology and structure during the prosess of Graphene prepare, as well as the Graphene and CNT on the silicone rubber electricaly conductivity and mechanical property. A synergy mechanism was proposed for that the synergistic effect of graphene and CNT can significantly increase electrical property of the silicone rubber.It is showed that, the oxidized time and oxidant dosage is increased, the graphite was oxidized more fully, which provides the favorable condition of preparing monolayer graphene. Washing step can be omitted during the preparation of graphite oxide, which is barely affected on the graphene morphology and structure. With the pyrolysis time growing, the volume resistivity of graphene is gradually reduced. When the pyrolysis time is shorter, the grphene can be well scattered in DMF, and it is functionalized by the oxidation groups. While, the pyrolysis time is longer, the graphene can get good electrical property, when the time is 40min, the volume resistivity is 0.01Ω·㎝.CNT/silicone rubber composite was prepared by solution method, while percolation threshold is 5 phr (mass fraction), volume resistivity is 4.21 x 106Ω·㎝, which is dropped 7 orders relatively to pure silicon rubber. But CNT has poor dispersion in silicon rubber while existing agglomeration. While used the same way, the percolation threshold of graphene/silicon rubber composite material is 2 phr, and volume resistivity is 1×10~5Ω·㎝. When the graphene is 3 phr, volume resistivity is 7×10~3Ω·cm, dropped 10 orders to silicon rubber, in which graphene is distributed evenly. When the graphene is 1 phr with 2.5 phr of CNT, the volume conductivity is 8×10~4Ω·cm, and without the significant agglomeration. Therefore, A synergy mechanism was proposed. When the graphene and CNT are dispersed in the silicon rubber, the contact probability of CNT and graphene is higher than that of CNT itself. So, CNT is formed the hydrogen bond with the graphene firstly, which is presented the aggregation of CNT itself, and has been well diapersed.The directly mixing method was compared with the solution method. There exists serious aggregation on CNT, which can not form the effective conductive network, while the graphene/silicon rubber has no change almostly, it has the same electrical property in the two methods. Therefore, graphene could be apply to the industrial production in the future.