Decoration of multi-walled carbon nanotubes by polymer wrapping and its application in MWCNT/polyethylene composites

An-En Hsiao,Mei-Wen Hsu,Shinn-Jen Chang,Shu-Ya Tsai

doi:10.1186/1556-276x-7-240

An-En Hsiao, Mei-Wen Hsu + Show 2 more

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https://doi.org/10.1186/1556-276x-7-240

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Abstract

We dispersed the non-covalent functionalization of multi-walled carbon nanotubes (CNTs) with a polymer dispersant and obtained a powder of polymer-wrapped CNTs. The UV–vis absorption spectrum was used to investigate the optimal weight ratio of the CNTs and polymer dispersant. The powder of polymer-wrapped CNTs had improved the drawbacks of CNTs of being lightweight and difficult to process, and it can re-disperse in a solvent. Then, we blended the polymer-wrapped CNTs and polyethylene (PE) by melt-mixing and produced a conductive masterbatch and CNT/PE composites. The polymer-wrapped CNTs showed lower surface resistivity in composites than the raw CNTs. The scanning electron microscopy images also showed that the polymer-wrapped CNTs can disperse well in composites than the raw CNTs.

Highlights

Carbon nanotubes (CNTs), having excellent electrical and extraordinary mechanical properties, are suitable to serve as a conductive filler or a strengthening material in polymer composites; their chemical inertia and smooth surface result in their lack of solubility and poor compatibility with polymers
Dispersion of the powder of polymer-wrapped CNTs Adding too much polymer dispersant will keep excessive polymer dispersant in composites, and it could result in composites with a poor mechanical property
To determine the optimal additive amount of the polymer dispersant for an effective polymer wrapping, we prepared the dispersion of CNTs in n-hexane with various additive amounts of polymer dispersant, filtered the dispersion with a 0.25-μm filter to remove the CNTs, and measured the UV absorption bands of these filtrates

Summary

Introduction

Carbon nanotubes (CNTs), having excellent electrical and extraordinary mechanical properties, are suitable to serve as a conductive filler or a strengthening material in polymer composites; their chemical inertia and smooth surface result in their lack of solubility and poor compatibility with polymers. The first method is so-called in situ polymerization method [1,2,3,4]: the monomers and CNTs are mixed well in a solution. The monomers are polymerized, and the CNTs can disperse in the polymer polymerized from the monomers. Non-covalent functionalization of CNTs by polymer wrapping is a feasible process to disperse CNTs in the solvent and that could not cause dramatic changes in the electronic properties of CNTs. It has been reported that a molecular structure containing functional groups can effectively absorb on the surface of CNTs and provide the dispersion of CNTs in a solution [9-16]. Preparing the polymer-wrapped CNTs by in situ

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