纳米级炭黑协同催化聚烯烃制备碳纳米管及其网状结构的研究

发布时间：2019-01-01 11:38

【摘要】：将廉价塑料转变为先进碳纳米材料能够有效降低制备成本,同时为废旧塑料的处理提供一种环保途径。但废旧塑料通常是几种聚烯烃的混合物,而目前常用的单金属催化剂往往不具有通用性,只能用于某一种塑料的催化。本研究发现利用一种三金属催化剂(Ni-Mo-Mg)与炭黑协同作用,能够高效催化不同种类聚烯烃制备碳纳米管及其网状结构。Ni-Mo-Mg催化剂原位催化聚丙烯(PP),聚乙烯(PE),聚苯乙烯(PS)及其混合物合成碳纳米管,最高产率分别为26.24%,28.36%,18.39%及31.66%。随着一种协同添加剂—炭黑(CB)的加入,碳纳米管产率最大值可分别提高至53.56%,65.95%,41.85%及59.83%。利用扫描电子显微镜(SEM),透射电子显微镜(TEM),高分辨透射电子显微镜(HRTEM),X射线衍射仪(XRD)及拉曼光谱(Raman)等对所制备的碳纳米管的微观形貌,结构,石墨化程度等进行表征与分析。研究表明,炭黑的添加能够改善碳纳米管形貌,同时使其石墨化程度得到提高。根据实验所得结果,本文对催化剂Ni-Mo-Mg的高效催化机理及其与炭黑的协同作用理论进行了探讨。本文还通过热解聚丙烯/Ni-Mo-Mg/炭黑共混物合成一种碳纳米管网状结构。扫描电子显微镜(SEM),透射电子显微镜(TEM)用于观察碳纳米管网状结构的微观形貌,X射线衍射仪(XRD),拉曼光谱(Raman),热重分析测试仪(TGA)及X射线光电子能谱(XPS)等则对其石墨化程度,热稳定性及表面组成进行了测试分析。结果证明,加入的CB-1不仅能够提高碳纳米管产率,且能使其互相连接,形成一种新型的网状结构。碳纳米管产率的增加与炭黑捕捉自由基的能力有关,连接碳纳米管的能力则取决于其粒径的大小。
[Abstract]:The conversion of cheap plastics to advanced carbon nanomaterials can effectively reduce the preparation cost and provide an environmental protection approach for the treatment of waste plastics. However, waste plastics are usually mixtures of polyolefin, but the single metal catalysts used at present are not universal and can only be used in the catalysis of one kind of plastics. It was found that a trimetallic catalyst (Ni-Mo-Mg) and carbon black could efficiently catalyze the preparation of carbon nanotubes (CNTs) from different polyolefins and their reticular structure by using a trimetal catalyst (Ni-Mo-Mg) and carbon black. In situ Ni-Mo-Mg catalyst catalyzed (PP), of polypropylene. Carbon nanotubes were synthesized from polyethylene (PE), polystyrene (PS) and its mixture. The highest yields of carbon nanotubes were 26.24% 28.36% and 31.66%, respectively. With the addition of a synergistic additive, carbon black (CB), the maximum yield of carbon nanotubes can be increased to 53.56% and 59.83%, respectively. Scanning electron microscope (SEM), (SEM), transmission electron microscope (TEM), high resolution transmission electron microscope (TEM), (HRTEM), X ray diffractometer (XRD) and Raman spectrum (Raman) were used to analyze the morphology and structure of the carbon nanotubes. The graphitization degree was characterized and analyzed. The results show that the addition of carbon black can improve the morphology and graphitization of carbon nanotubes. Based on the experimental results, the high efficiency catalytic mechanism of catalyst Ni-Mo-Mg and the theory of synergistic action with carbon black were discussed in this paper. A carbon nanotube network structure was also synthesized by pyrolysis of polypropylene / Ni-Mo-Mg/ carbon black blends. Scanning Electron microscope (SEM) (SEM), Transmission Electron microscope (TEM) used to observe the Microstructure of carbon Nanotubes (CNTs) and X-ray diffractometer (XRD), Raman Spectroscopy (Raman), The graphitization degree, thermal stability and surface composition were measured by thermogravimetric analyzer (TGA) and X-ray photoelectron spectroscopy (XPS). The results show that the addition of CB-1 can not only increase the yield of CNTs, but also make them interconnect with each other to form a new network structure. The increasing yield of carbon nanotubes is related to the ability of carbon black to capture free radicals, and the ability to connect carbon nanotubes depends on the size of the carbon nanotubes.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TQ127.11

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