The Carbonizing Performance And Applications Of Ni-Mo-Mg/Carbon Black Combined Catalysts On The Polypropylene

In recent years, among the chemical reactions that polymer are involved, achieving the carbonization of polymer itself has receive extremely attentions. As the flame retardancy of polymer will be improved when it is transformed into carbonaceous materials during pyrolyzation. Meanwhile, it probably becomes a feasible route to recycle waste plastic to advanced carbon nanomaterials. In this work, a method of combination of Ni-Mo-Mg and carbon black was applied to investigate the carbonization performance of polypropylene. Specifically, the influence of combined catalysts on the flame retardancy of polypropylene was studied by a series techniques. While the studies for synthesis of CNTs from polypropylene were investigated.The flame retardancy of polypropylene by combined catalysts was investigated by cone and limited oxygen index. It was found that when the both content of Ni-Mo-Mg and carbon black are 5 wt%, the PP/Ni-Mo-Mg/carbon black has a highest flame retardancy, the heat release rate is the lowest, and the LOI achieves 26.1%. The improvement of carbon black for the carbonization of polypropylene can be attribute the synergy with Ni-Mo-Mg. For the pyrolyzation at 750℃ and 550℃, the PP/5% Ni-Mo-Mg/5% carbon black blends gave 56% and 37.1% of yield. The results from SEM and TEM indicate that the carbon black can integrate CNTs to form a whole structure, maybe owing to it’s capture ability to radicals from polypropylene.In another way, we focus on the preparation of CNTs from polypropylene by the Ni-Mo-Mg/carbon black combined catalysts. The properties of CNTs were characterized by SEM, TEM, XRD, TG, FTIR and Raman measurement. The results demonstrated that the addition of carbon black not only increase the yield of CNTs dramatically, but also make the morphology of CNTs much better and promote the graphitization of CNTs.