TY - JOUR
T1 - The preparation of cation-functionalized multi-wall carbon nanotube/sulfonated polyurethane composites
AU - Gao, Renlong
AU - Ramirez, Sean M.
AU - Inglefield, David L.
AU - Bodnar, Robert J.
AU - Long, Timothy Edward
PY - 2013/4/1
Y1 - 2013/4/1
N2 - Covalent functionalization of multi-wall carbon nanotubes (MWCNTs) with minimal alteration to the MWCNT surface is important to achieve homogenously dispersed carbon nanotubes while maintaining their unique mechanical and electrical properties. Carboxylic acid derivatized MWCNTs (MWCNT-COOH) were covalently functionalized with 3,3′-iminobis(N,N-dimethylpropylamine) (DMPA). Upon subsequent quaternization of DMPA, dendritic ammonium cation-functionalized MWCNTs (MWCNT-DMPA+) were formed, where two ammonium cations were incorporated per amide site. Thermogravimetric analysis and X-ray photoelectron spectroscopy demonstrated successful covalent functionalization and formation of the surface-bound ammonium salt. Raman spectroscopy and atomic force microscopy indicated the absence of an appreciable decrease in the MWCNT aspect ratio. Compared with pristine MWCNTs and MWCNT-COOH, MWCNT-DMPA+ exhibited enhanced dispersibility in N,N-dimethylformamide (DMF) as observed with UV-Visible spectroscopy and transmission electron microscopy (TEM). In addition, blending the cation-bound MWCNT-DMPA+ with anion-bound sulfonated polyurethane in DMF generated novel composites with a nanotube content ranging from 0.5 to 5 wt.%. Characterization of the composite films using both field emission scanning electron microscopy and TEM revealed that MWCNT-DMPA+ exhibited uniform dispersion in sulfonated polyurethane matrices even at 5 wt.%. Tensile analysis showed that the modulus of the sulfonated polyurethane matrix linearly increased with MWCNT-DMPA+ content.
AB - Covalent functionalization of multi-wall carbon nanotubes (MWCNTs) with minimal alteration to the MWCNT surface is important to achieve homogenously dispersed carbon nanotubes while maintaining their unique mechanical and electrical properties. Carboxylic acid derivatized MWCNTs (MWCNT-COOH) were covalently functionalized with 3,3′-iminobis(N,N-dimethylpropylamine) (DMPA). Upon subsequent quaternization of DMPA, dendritic ammonium cation-functionalized MWCNTs (MWCNT-DMPA+) were formed, where two ammonium cations were incorporated per amide site. Thermogravimetric analysis and X-ray photoelectron spectroscopy demonstrated successful covalent functionalization and formation of the surface-bound ammonium salt. Raman spectroscopy and atomic force microscopy indicated the absence of an appreciable decrease in the MWCNT aspect ratio. Compared with pristine MWCNTs and MWCNT-COOH, MWCNT-DMPA+ exhibited enhanced dispersibility in N,N-dimethylformamide (DMF) as observed with UV-Visible spectroscopy and transmission electron microscopy (TEM). In addition, blending the cation-bound MWCNT-DMPA+ with anion-bound sulfonated polyurethane in DMF generated novel composites with a nanotube content ranging from 0.5 to 5 wt.%. Characterization of the composite films using both field emission scanning electron microscopy and TEM revealed that MWCNT-DMPA+ exhibited uniform dispersion in sulfonated polyurethane matrices even at 5 wt.%. Tensile analysis showed that the modulus of the sulfonated polyurethane matrix linearly increased with MWCNT-DMPA+ content.
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U2 - 10.1016/j.carbon.2012.11.010
DO - 10.1016/j.carbon.2012.11.010
M3 - Article
AN - SCOPUS:84872849398
SN - 0008-6223
VL - 54
SP - 133
EP - 142
JO - Carbon
JF - Carbon
ER -