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Preparation and orientation behavior of multi‐walled carbon nanotubes grafted with a side‐chain azobenzene liquid crystalline polymer

Key Laboratory of Polymeric Materials and Application Technology of Hunan Province, Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province, College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province, PR China
Polymer International (Impact Factor: 2.13). 09/2010; 60(1):93 - 101. DOI: 10.1002/pi.2917

ABSTRACT Covalent functionalization of multi‐walled carbon nanotubes (MWNTs) with side‐chain azobenzene liquid crystalline poly{6‐[4‐(4‐methoxyphenylazo)phenoxy]hexyl methacrylate} (PMMAZO) was successfully achieved via atom transfer radical polymerization. The resultant samples were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and transmission electron microscopy. The results of differential scanning calorimetry and polarized optical microscopy show that the liquid crystalline behavior of PMMAZO‐functionalized carbon nanotubes (CNT‐PMMAZO) is similar to that of the PMMAZO homopolymer. The orientation of MWNTs and CNT‐PMMAZO in a PMMAZO matrix in the presence of an electric field was investigated. The results indicate that the orientation of MWNTs is dominated by the viscosity of the matrix, but the orientation of CNT‐PMMAZO is controlled by both the viscosity and the presence of a liquid crystalline phase ascribed to the compatibility between MWNTs and PMMAZO becoming better after covalent modification. Copyright © 2010 Society of Chemical Industry

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