石墨烯功能化及其在聚丙烯基体中取向分布研究

发布时间：2018-05-07 19:01

本文选题：功能化石墨烯 + 聚丙烯　；参考：《西南大学》2015年硕士论文

【摘要】：石墨烯是一种由碳原子以sp2杂化轨道组成的六角型呈蜂巢晶格的平面薄膜,只有一个碳原子厚度的二维纳米材料,具有优越的热学、力学、光学、电学等性能,从而成为当前材料科学领域的研究热点,广泛应用于聚合物复合材料中。然而它与高分子聚合物混合的过程中还有很多亟待解决的问题：比如,石墨烯如何在聚合物基体中分散和取向问题；如何增强石墨烯与聚合物基体界面的相互作用等等。针对以上问题,本文通过对石墨烯表面功能化处理,提高其在聚合物中的分散性以及石墨烯与聚合物基体界面作用；在此基础上,将功能化的石墨烯与聚丙烯制备出聚丙烯功能化石墨烯复合材料。另外,运用实验室自主组装设计的剪切诱导取向挤出(SIOE)成型设备制备出具有取向分布的功能化石墨烯聚丙烯复合材料。(1)通过Hummers法将鳞片石墨制备出氧化石墨(GO),再将其在4,4-二苯基甲烷二异氰酸酯(MDI)的作用下与硬脂酸反应制备得功能化石墨烯(FGs)。通过运用傅立叶红外光谱(FT-IR)、X射线光电子能谱(XPS)、X射线衍射(XRD)、热重分析(TGA)和透射电子显微镜(TEM)来测试分析FGs的结构和性能。结果表明通过MDI的共价接枝改性将硬脂酸接到氧化石墨烯表面,成功的制备出了功能化石墨烯粒子(FGs),它与有机溶剂的相容性较好,非极性得到了增强,从而与聚合物基体有较好的相容性,功能化石墨烯粒子层与层间距离增大,热稳定性较氧化石墨烯也有很显著的提高。(2)将不同含量的功能化石墨烯粒子与等规聚丙烯(iPP)通过熔融共混的方式制备出聚丙烯/功能化石墨烯(iPP/FGs)复合材料。并通过运用X射线衍射(XRD)、热重分析(TGA)、差示扫描量热法(DSC)、扫描电子显微镜(SEM)和万能力学拉伸试验来测试分析聚丙烯/功能化石墨烯复合材料的结构和性能。实验结果表明FGs粒子能够较好的分散在聚丙烯基体中,同时与界面有较强的相互作用,聚丙烯复合材料的结晶度、热稳定性以及力学性能较聚丙烯/鳞片石墨复合材料、聚丙烯/氧化石墨烯复合材料有显著提高。(3)本课题组自主设计组装了剪切诱导取向挤出(SIOE)成型设各,该设备是在单螺杆挤出机的机头出料口处加装自主设计的取向成型模块单元,再将挤出的片层材料通过流延辊拉伸冷却成型。该设备主要是通过添加不同数量的取向单元模块来控制聚合物流体受到剪切力的大小,从而调控填料和基体中的分散排布情况。我们首先将等规聚丙烯和FGs用双螺杆挤出机造粒制备出母料,再运用取向挤出成型设备制备出不同FGs含量不同取向单元下的聚丙烯/功能化石墨烯(iPP/FGs)复合材料。采用X射线衍射(XRD)、热重分析(TGA)、差示扫描量热法(DSC)、扫描电子显微镜(SEM)、二维广角X射线衍射(2D-WAXD)、气体渗透仪(GPT)和万能力学拉伸试验对其结构、形态和性能进行了表征。实验结果表明,经过取向单元挤出成型的聚丙烯/功能化石墨烯(iPP/FGs)复合材料中的FGs填料粒子明显的沿流动方向定向排列,随着取向单元的增加,FGs分散越均匀,同时其引起聚丙烯晶体发生取向,晶体取向度大致随取向的单元依次递增。由于FGs片层的定向排布,使得聚丙烯/功能化石墨烯(iPP/FGs)复合材料具有较好的力学性能和阻隔性能。这对开发高性能的力学和阻隔高分子材料具有借鉴意义。
[Abstract]:Graphene is a planar film of six angle type of honeycomb lattice, consisting of carbon atoms with SP2 hybrid orbits. It has only one carbon atom thickness of two-dimensional nanomaterials. It has excellent thermal, mechanical, optical and electrical properties. It has become a hot research field in the field of material science and is widely used in polymer composites. However, it is widely used in polymer composites. In the process of mixing with polymers, there are many problems to be solved: for example, how to disperse and orientate graphene in the polymer matrix; how to enhance the interaction between graphene and the interface of the polymer matrix. On the basis of the dispersivity of graphene and the interface of the polymer matrix, the functionalized graphene and polypropylene have been prepared to prepare the polypropylene function fossils compound material. In addition, the functionalized functionalized fossil graphene polymerization with orientation distribution was prepared by the shear induced oriented extrusion (SIOE) molding equipment designed by the laboratory self-assembled design. Propene composites. (1) graphite oxide (GO) was prepared by Hummers method to prepare functional fossil graphene (FGs) with stearic acid under the action of 4,4- two phenyl methane diisocyanate (MDI). By using Fu Liye infrared spectroscopy (FT-IR), X ray photoelectron spectroscopy (XPS), X ray diffraction (XRD), thermogravimetric analysis (TGA). The structure and properties of FGs were tested and analyzed by transmission electron microscope (TEM). The results showed that the stearic acid was prepared by covalent graft modification of MDI to the surface of graphene oxide. The functional fossil Mo particle (FGs) was successfully prepared. It has good compatibility with organic solvents, and the non polarity is enhanced, which is better than the polymer matrix. Compatibility, the distance between the layer and interlayer of functional fossils increases and the thermal stability is significantly higher than that of graphene oxide. (2) polypropylene / functional fossil mo (iPP/FGs) composites are prepared by melt blending of different contents of functionalized Silene particles and isotactic polypropylene (iPP). And X ray diffraction (XR) is used. D), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and universal mechanical tensile test were used to analyze the structure and properties of polypropylene / functionalized graphene composites. The experimental results show that the FGs particles can be well dispersed in the polypropylene matrix and have a strong interaction with the interface, and the polypropylene compound is complex. The crystallinity, thermal stability and mechanical properties of the composite are better than that of polypropylene / scale graphite composites, and the polypropylene / graphene oxide composite material has been significantly improved. (3) the research group has independently designed and assembled the shear induced oriented extrusion (SIOE) molding equipment. This equipment is installed at the outlet of the single screw extruder. In order to control the dispersion of the polymer fluid by adding a different number of orientation unit modules to control the size of the shear force in the filler and the matrix, we first use the isotactic polypropylene and FGs twin-screw. The extruder is prepared by granulation, and then the polypropylene / functional fossil (iPP/FGs) composites with different FGs content are prepared by the orientation extrusion molding equipment. X ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscope (SEM), two-dimensional wide-angle X ray diffraction (2D-WAXD), and gas are used. The structure, morphology and properties were characterized by body osmotic apparatus (GPT) and universal mechanical tensile test. The experimental results showed that the FGs filler particles in the polypropylene / functional fossil mo (iPP/FGs) composites formed by the orientation unit were obviously arranged along the direction of flow, and the dispersion of FGs was more uniform with the increase of orientation units. The orientation of polypropylene crystal and the orientation degree of the crystal increase in turn. The polypropylene / functional fossil mo (iPP/FGs) composites have good mechanical and barrier properties because of the directional arrangement of the FGs lamellae, which is of reference to the development of high performance mechanical and barrier polymer materials.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11;TQ325.14

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