Functionalized multiwalled carbon nanotubes in mild polyphosphoric acid/phosphorous pentoxide/phosphoric acid and their composites with epoxy resin. Issue 7 (14th November 2013) - Li, Na
Abstract Multiwalled carbon nanotubes (MWCNTs) were functionalized through "Friedel‐Craft" acylation with 1, 3, 5‐Benzenetricarboxylic acid (BTC) in mild polyphosphoric acid (PPA)/ phosphorus pentoxide (P2O5)/phosphoric acid (PA) medium at 130°C. The high‐resolution transmission electron microscopy, Raman spectra, and X‐ray photoelectron spectra (XPS) were used to characterize the surface microstructure nature of functionalized MWCNTs in optimum PPA/P2O5/PA medium. The thermostability of functionalized MWCNTs was characterized by thermogravimetric analysis. The maximum rate of weight loss temperature increased as compared with pristine MWCNTs. The dispersion properties of MWCNTs and the flexural properties of the MWCNTs/epoxy composites affected by MWCNTs functionalization are investigated. It is demonstrated that the functionalized MWCNTs exhibit much better dispersability than pristine MWCNTs. The attached BTC molecules arising from the functionalization effectively improved interfacial adhesion between the epoxy resin and functionalized MWCNTs through covalent bonds, resulting in improved flexural properties compared with those without functionalization. POLYM. COMPOS., 35:1275–1284, 2014. © 2013 Society of Plastics Engineers