反复机械拉伸法在聚合物中定向排列单壁纳米碳管

Alignment of SWNTs in Polymer by Repeated Stretching Method

在原位聚合过程中，采用反复机械拉伸的方法，将半干状态的SWNTs／PMMA复合体系沿同一方向反复拉伸，合成了SWNTs在PMMA基体中定向排列并均匀分散的SWNTs／PMMA复合材料SEM和TEM照片分析表明，SWNTs沿拉伸方向排列且均匀分散；不同入射角度下的偏振拉曼光谱分析也表明其定向性良好；电学和力学性能测量结果进一步表明复合材料表现出显著的各向异性，且电导率和力学性能沿SWNTs排列方向得到明显提高；建立了SWNTs在拉伸过程中定向排列的动力学模型，理论分析了SWNTs在流股剪切力作用下在复合体中沿拉伸方向定向排列的机理。

The SWNTs/PMMA composite with good alignment, uniformity and dispersion of SWNTs were fabricated in situ polymerization by using repeated meehanieal stretehing method. The semidried mixture was stretehed along one direetion repeatedly to align SWNTs in the eomposite matrix. The SEM and the TEM mierograph demonstrated that SWNTs were aligned in the stretehing direetion and well dispersed in the matrix. Polarized Raman speetra with various ineidenee angles indieated that SWNTs had a good alignment in the eomposite. The eomposite presented distinet anisotropie eleetrieal and meehanieal properties, and it showed higher eleetrieal eonduetivity and the meehanieal properties along the stretehing direetion than vertieal to it. The dynamie model of SWNTs realigning in the stretehing proeess was established in this paper to explain the meehanism of the SWNTs orientation along stretehing direetion under the aetion of stream shear stress in matrix.