An Easy Route to Lower-Destructive and Highly Functionalized Multi-Walled Carbon Nanotubes with Thermotropic Liquid Crystalline Polymer on a Large Scale

AbstractAn easy and less-destructive method has been developed to highly functionalize multi-walled carbon nanotubes (MWCNTs) with thermotropic liquid crystalline polymer (TLCP) via an elimination reaction between TLCP terminated phenolic hydroxyl groups and p-benzyl chloride groups of active poly(4-chloromethyl styrene) (PCMS) on the surface of tubes, where MWCNTs were functionalized with PCMS through the esterification reaction of carboxylate of the former and p-benzyl chloride groups of the latter in the presence of a phase-transfer catalyst. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) confirmed liquid crystal behavior of TLCP. The high density of covalent bonding between TLCP and nanotubes was confirmed by FTIR and Raman, resulting in a high grafting efficiency, as high as 18 wt% of TGA. Microscopic observations clearly displayed thick TLCP layers formed on the MWCNT surface.KeywordsCarbon nanotubeCovalent bondingFunctionalizationThermotropic liquid crystalline polymer