Structural interpretations of deformation and fracture behavior of polypropylene/multi-walled carbon nanotube composites
Structural interpretations of deformation and fracture behavior of polypropylene/multi-walled carbon nanotube composites
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DOI：
10.1016/j.actamat.2008.01.010
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发表时间：
2008-06-01
期刊：
影响因子：
9.4
通讯作者：
Jehnichen, Dieter
中科院分区：
文献类型：
--
作者：
Ganss, Martin;Satapathy, Bhabani K.;Jehnichen, Dieter
采用透射电子显微镜（TEM）、原子力显微镜（AFM）、扫描电子显微镜（SEM）、广角X射线衍射（WAND）、差示扫描量热仪（DSC）和偏光显微镜等手段研究了聚丙烯（PP）/多壁碳纳米管（MWNT）复合材料的变形和抗裂行为，并讨论了其与结构属性的关系。该复合材料由工业上可获得的MWNT通过挤出熔融混合和注射成型而制备。在应力-应变测量中，已经观察到在低MWNT含量下的屈服应力和杨氏模量的强烈增加，这归因于通过良好的聚合物-纳米管粘附力在碳纳米管和聚丙烯基体之间的有效载荷传递，如SEM所示。机械性能的增强程度高于1.5重量%，碳纳米管的成簇趋势明显增强，使MWNT的成簇率降低。几个理论模型已被考虑到解释的机械性能，并证明这些模型的适用性，调查中的系统。采用基于屈服后断裂力学（PYFM）概念的基本断裂功（EWF）方法研究了混凝土的抗裂性能。在0.5wt.%时观察到非必要断裂功的最大值。与纯PP相比，MWNT表现出增强的韧性，随后随着MWNT含量增加到1.5wt.%而急剧下降显示出韧性到半韧性的转变。裂纹扩展方面的动力学的研究已经揭示了一个定性的图片的性质，这种过渡的断裂模式。(C)2008 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The deformation and crack resistance behavior of polypropylene (PP) multi-walled carbon nanotube (MWNT) composites have been studied and their interrelation to the structural attributes studied by transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAND), differential scanning calorimetry (DSC) and polarization light microscopy has been discussed. The composites were produced from industrial available MWNT by extrusion melt-mixing and injection-molding. In stress-strain measurements a strong increase in the yield stress and the Young's modulus at low MWNT contents has been observed, which was attributed to an efficient load transfer between the carbon nanotubes and polypropylene matrix through a good polymer-nanotube adhesion as indicated by SEM. The extent of enhancement in mechanical properties above 1.5 wt.% of MWNT decreased due to an apparently increased tendency of clustering of carbon nanotubes. Several theoretical models have been taken into account to explain the mechanical properties and to demonstrate the applicability of such models to the system under investigation. The crack resistance behavior has been studied with the essential work of fracture (EWF) approach based on post-yield fracture mechanics (PYFM) concept. A maximum in the non-essential work of fracture was observed at 0.5 wt.% MWNT demonstrating enhanced toughness compared to pure PP, followed by a sharp decline as the MWNT content was increased to 1.5 wt.% reveals a ductile-to-semi-ductile transition. Studies on the kinetics of crack propagation aspects have revealed a qualitative picture of the nature of such a transition in the fracture modes. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.