Ultrahigh-shear processing for the preparation of polymer/carbon nanotube composites
Ultrahigh-shear processing for the preparation of polymer/carbon nanotube composites
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DOI：
10.1016/j.carbon.2007.07.017
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发表时间：
2007-10-01
期刊：
影响因子：
10.9
通讯作者：
Shimizu, Hiroshi
中科院分区：
文献类型：
--
作者：
Chen, Guang-Xin;Li, Yongjin;Shimizu, Hiroshi
采用新型超高剪切挤出机将聚偏氟乙烯(PVDF)与多壁碳纳米管(MWCNT)熔融共混，制备了聚偏氟乙烯(PVDF)/多壁碳纳米管(MWCNT)复合材料。采用一种特殊的反馈型螺杆，在较高的螺杆转速下，获得了较高的剪切场和纳米管在聚合物基质中的均匀分散。用拉曼光谱和扫描电子显微镜研究了纳米管在PVDF中的相互作用和分散情况。研究了这些复合材料的线性粘弹性行为和导电性。在低频下，随着纳米管载荷量的增加，材料的储能剪切模数(G‘)几乎与频率无关，这表明在这些复合材料中出现了类固体行为。通过G‘与纳米管载荷的关系图和幂函数拟合，发现高剪切复合材料的流变阈值约为0.96wt%，而低剪切复合材料的流变阈值约为1.76wt%。高剪切加工复合材料的电渗流阈值低于低剪切加工复合材料。(C)2007爱思唯尔有限公司。保留所有权利。
Poly(vinylidene fluoride) (PVDF)/multiwalled carbon nanotube (MWCNT) composites were prepared using a novel ultrahigh-shear extruder by directly mixing MWCNT with PVDF in the molten state. A special feedback-type screw was used to obtain a high shear field and obtain a very uniform dispersion of the nanotubes in the polymer matrix under a higher screw rotation speed. Raman spectroscopy and scanning electron microscopy were used to determine the interaction and dispersion of nanotubes in the PVDF. The linear viscoelastic behavior and electrical conductivity of these composites were investigated. At low-frequencies, the storage shear modulus (G') becomes almost independent of the frequency as nanotube loading increases, suggesting the onset of solid-like behavior in these composites. By plotting G' vs. nanotube loading and fitting with a power-law function, we found that the rheological threshold of high-shear processed composites is about 0.96 wt% whereas that of low-shear processed composites is about 1.76 wt%. The electrical percolation threshold of high-shear processed composites is lower than that of low-shear processed composites. (c) 2007 Elsevier Ltd. All rights reserved.