Effects of multi-walled carbon nanotubes on rheological and physical properties of polyamide-based thermoplastic elastomers
Effects of multi-walled carbon nanotubes on rheological and physical properties of polyamide-based thermoplastic elastomers
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DOI：
10.1007/s13367-012-0027-9
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发表时间：
2012-09-01
影响因子：
1.3
通讯作者：
Chae, Dong Wook
中科院分区：
文献类型：
--
作者：
Bae, Won-Sik;Kwon, Oh Joo;Chae, Dong Wook
将聚酰胺基热塑性弹性体（Pebax（R））与多壁碳纳米管（MWNTs：0.25类似于5wt%）熔融混配，并研究了流变性和物理性能随MWNT含量的变化。添加0.5wt% MWNTs的纳米复合材料的结晶温度（T-c）提高了约100 ℃。8摄氏度，但通过进一步添加而降低。此外，MWNTs的存在拓宽了T-c峰随着纳米管含量的增加。与此相反，熔融行为的影响不大的MWNTs的存在下，所有的组合物。MWNTs的掺入使复合粘度随MWNTs含量的增加而增加，并且从1wt%开始观察到突然增加。此外，随着MWNT含量的增加，低牛顿流动区消失，从1 wt%负载表现出显着的剪切变稀行为。储能模量以与粘度类似的方式随着MWNT含量而增加。Casson图显示所有样品的非零正截距。特别地，从1重量%负载观察到屈服应力的突然增加。在Cole-Cole图中，纳米复合材料给出了偏离纯Pebax的曲线，并且斜率随着MWNT含量的增加而减小。由粘弹性参数计算的弛豫时间随纳米管含量的增加而增加，但增加的幅度随频率的增加而减小。从2wt%的MWNTs，观察到的导电性，表明电渗流存在于1.5和2wt%之间。在0.25wt%负载下，拉伸强度略微增加，但通过进一步添加而逐渐降低。多壁碳纳米管的引入增加了拉伸模量与纳米管的内容。此外，随着MWNT含量的增加，延性性能降低，导致韧性低。
The polyamide-based thermoplastic elastomers (Pebax (R)) were melt compounded with multi-walled carbon nanotubes (MWNTs: 0.25 similar to 5 wt%) and the variation of rheological and physical properties with MWNT contents was investigated. The crystallization temperature (T-c) of the nanocomposites with 0.5 wt% MWNTs was most increased by ca. 8 degrees C, but it was decreased by further addition. In addition, the presence of MWNTs broadened the T-c peak with increasing nanotube contents. In contrast, the melting behavior was little influenced by the presence of MWNTs for all compositions. The incorporation of MWNTs increased the complex viscosity with MWNT contents and the abrupt increase was observed from 1 wt%. In addition, lower Newtonian flow region became disappearing with increasing MWNT contents, exhibiting notable shear thinning behavior from 1 wt% loading. Storage modulus was increased with MWNT contents in a similar manner to viscosity. Casson plot demonstrated a non-zero positive intercept for all the samples. In particular, the abrupt increase of yield stress was observed from 1 wt% loading. In the Cole-Cole plot, the nanocomposites gave a deviated curve from pure Pebax and the slope was decreased with increasing MWNT contents. The relaxation time calculated from viscoelastic parameters was increased with nanotube contents, but the increasing extents were reduced with increasing frequency. From 2 wt% MWNTs, the electrical conductivity was observed, indicating that the electrical percolation existed between 1.5 and 2 wt%. At 0.25 wt% loading the tensile strength was slightly increased, but it was gradually decreased by further addition. The introduction of MWNTs increased the tensile modulus with nanotube contents. In addition, ductile properties were reduced with increasing MWNT contents, resulting in low toughness.