Morphological and mechanical properties of carbon nanotube/polymer composites via melt compounding
Morphological and mechanical properties of carbon nanotube/polymer composites via melt compounding
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DOI：
10.1002/polb.20743
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发表时间：
2006-03-01
影响因子：
--
通讯作者：
Gorga, RE
中科院分区：
文献类型：
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作者：
Dondero, WE;Gorga, RE
研究了多壁碳纳米管（MWNT）/聚丙烯（PP）纳米复合材料的力学性能和形态与纳米管取向和浓度的关系。通过熔融混合，然后熔融拉伸，使用具有专门设计的缠绕装置的双螺杆微型挤出机，MWNTs的分散和取向在PP中进行了优化。拉伸测试显示，对于PP中的0.25重量% MWNT（超过纯PP），韧性增加32%。此外，模量增加了138%与0.25重量%的MWNTs。透射电子显微镜和扫描电子显微镜表明定性纳米管分散和取向。广角X射线衍射被用来研究晶体形态和取向，通过计算复合材料的赫尔曼的取向因子作为纳米管负载和取向的函数。向取向样品中添加纳米管导致结晶形态从a和中间相转变为仅a相。此外，添加纳米管（无取向）被发现会导致各向同性的PP晶体，和拉伸被证明可以通过取向因子提高晶体取向。此外，差示扫描量热法定性显示整体结晶度变化不大。总之，这项工作表明，熔融混合与熔融拉伸相结合，产生了MWNT/PP复合材料，具有独特的强度和韧性组合，适用于先进的纤维应用，如智能纤维和高性能织物。(c)2006 Wiley Periodicals，Inc.
The mechanical properties and morphology of multiwall carbon nanotube (MWNT)/polypropylene (PP) nanocomposites were studied as a function of nanotube orientation and concentration. Through melt mixing followed by melt drawing, using a twin screw mini-extruder with a specially designed winding apparatus, the dispersion and orientation of MWNTs was optimized in PP Tensile tests showed a 32% increase in toughness for a 0.25 wt % MWNT in PP (over pure PP). Moreover, modulus increased by 138% with 0.25 wt % MWNTs. Transmission electron microscopy and scanning electron microscopy demonstrated qualitative nanotube dispersion and orientation. Wide angle X-ray diffraction was used to study crystal morphology and orientation by calculating the Herman's orientation factor for the composites as function of nanotube loading and orientation. The addition of nanotubes to oriented samples causes the crystalline morphology to shift from a and mesophase to only a phase. Furthermore, the addition of nanotubes (without orientation) was found to cause isotropization of the PP crystal, and drawing was shown to improve crystal orientation through the orientation factor. In addition, differential scanning caloriometry qualitatively revealed little change in overall crystallinity. In conclusion, this work has shown that melt mixing coupled with melt drawing has yielded MWNT/PP composites with a unique combination of strength and toughness suitable for advanced fiber applications, such as smart fibers and high-performance fabrics. (c) 2006 Wiley Periodicals, Inc.