碳基高分子复合材料的制备及性能研究

发布时间：2018-04-18 05:31

本文选题：导电材料 + 碳纳米管　；参考：《太原理工大学》2015年硕士论文

【摘要】：富勒烯、碳纳米管、石墨烯等碳纳米材料因具有独特物理和化学性能而被广泛应用于生物医学、电子工业、磁性材料、光电材料、分子器件、汽车工业、隐身技术等领域。膨胀石墨因其具有较大的比表面积和特殊形态，易于在聚合物基体中形成导电通道，在改善聚合物的电性能，力学性能方面具有广阔的应用前景。利用纳米插层技术制备出低渗滤阈值的碳基导电高分子复合材料是人们关注的热点之一。本文分别以聚丙烯、聚乙烯为基体，以碳材料为填料，制备了膨胀石墨/多壁碳纳米管/聚丙烯（EG/MWCNTs/PP）、膨胀石墨/炭黑/聚乙烯（EG/CB/PE）高分子导电复合材料，采用差示扫描量热仪（DSC）、热失重仪（TGA）、万能拉力机、扫描电子显微镜（SEM）等不同的表征手段研究了碳材料用量对聚合物复合材料性能影响。研究结果表明： 1.在膨胀石墨/多壁碳纳米管/聚丙烯（EG/MWCNTs/PP）体系中，片层状膨胀石墨和纤维状多壁碳纳米管在聚丙烯基体中形成了完整而稳定的导电“网络”，而且具有良好的分散效果，致使聚丙烯复合材料的拉伸强度和断裂伸长率明显提高，在EG/MWCNTs=0.1/0.1份时，复合材料的拉伸强度和断裂伸长率达到最大值。复合碳基材料的加入，影响了聚丙烯的结晶行为，改善了聚丙烯复合材料的耐热性能，显著提高了聚丙烯复合材料的导电性能，其逾渗阀值在到EG/MWCNTs为0.1/0.1到0.5/0.5份之间。聚丙烯体系非等温结晶数据符合莫氏方程。通过Kissinger方法计算出，当填料EG/MWCNTs=0.1/0.1份，复合材料体系的结晶活化能最低，，随着所加入填料含量的不断增加，结晶活化能逐渐增大。 2.在膨胀石墨/炭黑/聚乙烯（EG/CB/PE）体系中，层状膨胀石墨和球状炭黑在聚乙烯基体中均匀分散，炭黑在体系中起到了“桥梁”作用，与膨胀石墨形成了稳定的空间导电通道。由于这两种导电填料间隙之间的隧道效应使得聚乙烯基复合材料具有优良的导电性能。当EG/CB=0.2/0.4份时，复合材料的拉伸强度和断裂伸长率达到最小值。聚乙烯体系非等温结晶过程符合莫氏方程。通过Kissinger方法计算出，当填料EG/CB=0.2/0.4份时，复合材料体系的结晶活化能最低，达到222.4KJ/mol，这说明碳基材料在的加入降低了体系结晶活化能，有利于体系结晶。
[Abstract]:Fullerene, carbon nanotubes, graphene and other carbon nanomaterials have been widely used in biomedicine, electronic industry, magnetic materials, optoelectronic materials, molecular devices, automobile industry, stealth technology and other fields because of their unique physical and chemical properties.Because of its large specific surface area and special morphology, expanded graphite is easy to form conductive channels in polymer matrix, which has a broad application prospect in improving the electrical properties and mechanical properties of polymer.Carbon-based conductive polymer composites with low percolation threshold were prepared by nano-intercalation technology.In this paper, the expanded graphite / multiwall carbon nanotubes / polypropylene (PP) EGR / MWCNT / PP / PP / expanded graphite / carbon black / polyethylene (PE) conductive polymer composites were prepared by using polypropylene and polyethylene as the matrix and carbon materials as fillers, respectively.The effects of carbon content on the properties of polymer composites were studied by means of differential scanning calorimeter (DSC), thermogravimetry (TGA), universal tension machine and scanning electron microscope (SEM).The results show that:1.In the system of expandable graphite / multiwall carbon nanotubes / PP / EGR / MWCNTs / PP, lamellar expanded graphite and fibrous multiwalled carbon nanotubes form a complete and stable conductive "network" in polypropylene matrix, and have good dispersion effect.As a result, the tensile strength and elongation at break of polypropylene composites increased obviously, and the tensile strength and elongation at break reached the maximum when EG/MWCNTs=0.1/0.1 content was used.The addition of carbon based composite material affects the crystallization behavior of PP, improves the heat resistance of PP composites, and improves the conductivity of PP composites. The percolation threshold of PP composites is between 0.1 / 0.1 and 0.5 / 0.5 phr of EG/MWCNTs.The nonisothermal crystallization data of polypropylene system accord with Morse equation.The results of Kissinger method show that the crystallization activation energy of the composite system is the lowest when the filler EG/MWCNTs=0.1/0.1 fraction is added, and the crystallization activation energy increases with the increasing of the filler content.2.In the expanded graphite / carbon black / polyethylene (PE) system, the layered expanded graphite and the spherical carbon black dispersed uniformly in the polyethylene matrix. The carbon black acted as a "bridge" in the system and formed a stable space conductive channel with the expanded graphite.Due to the tunneling effect between the two conductive fillers, polyethylene matrix composites have excellent electrical conductivity.When EG/CB=0.2/0.4 is used, the tensile strength and elongation at break of the composites reach the minimum value.The non isothermal crystallization process of polyethylene system accords with Morse equation.The results of Kissinger method show that the crystallization activation energy of the composites is the lowest when the filler is EG/CB=0.2/0.4, reaching 222.4 KJ / mol, which indicates that the addition of carbon-based materials reduces the crystallization activation energy of the system and is beneficial to the crystallization of the composites.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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