In situ preparation and continuous fiber spinning of poly(p-phenylene benzobisoxazole) composites with oligo-hydroxyamide-functionalized multi-walled carbon nanotubes
In situ preparation and continuous fiber spinning of poly(p-phenylene benzobisoxazole) composites with oligo-hydroxyamide-functionalized multi-walled carbon nanotubes
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DOI：
10.1016/j.polymer.2008.04.003
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发表时间：
2008-05
期刊：
影响因子：
4.6
通讯作者：
Chengjun Zhou;Shanfeng Wang;Yi Zhang;Q. Zhuang;Zhe‐wen Han
中科院分区：
文献类型：
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作者：
Chengjun Zhou;Shanfeng Wang;Yi Zhang;Q. Zhuang;Zhe‐wen Han
采用接枝自组装法制备了具有低聚羟基酰胺（oHA）的多壁碳纳米管（MWNTs）。原始MWNT首先氧化成MWNT-COOH，然后通过酰氯官能化成MWNT-COCl。MWNT-COCl与oHA共聚以产生oHA接枝的MWNTs（MWNT-oHA）。MWNT-oHA中的oHA壳的厚度约为7.5nm。MWNT-oHA在极性溶剂中具有显著的溶解度和良好的热稳定性，因为在加热时发生特征性脱水闭环并形成热更稳定的苯并恶唑组分。通过原位聚合，MWNT-oHA进一步与刚性棒聚合物基质聚（对亚苯基苯并双恶唑）（PBO）共价结合。采用干喷湿纺技术制备了不同碳纳米管组成的连续PBO-MWNT复合纤维。对PBO-MWNT复合纤维的结构和形态进行了表征，并对其力学性能、热性能、导电性能进行了研究。由于多壁碳纳米管在PBO中具有良好的分散性和高度的取向性，以及两组分间界面相互作用的增强，PBO-MWNT复合纤维的拉伸模量、拉伸强度和热稳定性得到了提高。此外，在PBO-MWNT复合膜和复合纤维的内核中发现了增加的导电性;然而，在外表面上没有。这一现象可以用渗流模型、纤维的非均匀形态和纳米管在纤维横截面上的分布来解释。
A graft-from approach has been performed to achieve covalent functionalization of multi-walled carbon nanotubes (MWNTs) with oligo-hydroxyamide (oHA). Pristine MWNT was first oxidized to MWNT-COOH and then functionalized to MWNT-COCl by acyl chloride. MWNT-COCl was copolymerized with oHA to produce oHA-grafted MWNTs (MWNT-oHA). The thickness of the oHA shell in MWNT-oHA is about 7.5nm. MWNT-oHA has a remarkable solubility in polar solvents and a good thermal stability because characteristic dehydrative ring closure occurs upon heating and forms a thermally more stable benzoxazole component. MWNT-oHA has been further covalently incorporated with a rigid-rod polymer matrix, poly(p-phenylene benzobisoxazole) (PBO), through in situ polymerization. Continuous PBO–MWNT composite fibers with different MWNT compositions have been fabricated using dry-jet wet-spinning technique. The structure and morphology of PBO–MWNT composite fibers have been characterized and their mechanical, thermal, conducting properties have been investigated. The tensile modulus, tensile strength, and thermal stability of PBO–MWNT composite fibers have been improved because of a good dispersion and high alignment of MWNTs in PBO as well as enhanced interfacial interaction between these two components. Furthermore, increased conductivity has been discovered in the PBO–MWNT composite films and the inner core of the composite fibers; however, not on the outer surface. The phenomena can be interpreted using percolation model together with the heterogeneous fiber morphology and nanotube distribution over the cross-section of the fiber.