(693g) The Effects of Bingel Functionalization On CoMoCAT® SWNT and Their Dispersibility In Unsaturated Polyester Resin

Sidewall esterification of single-walled carbon nanotubes (SWNT) can be achieved via the Bingel reaction.  Stemming from the cyclopropanation of fullerenes, Bingel reaction conditions require sonication of nanotubes in 1,2-dichlorobenzene (o-DCB) followed by treatment with diethylbromomalonate in presence of the base 1,8-diazabicyclo[5.4.0]undec-7-ene.  However, sonication of o-DCB generates a significant amount of sonopolymer.  In contrast to previous studies with HiPco SWNT, we find that exposing CoMoCAT^® SWNT (CG 200) to Bingel reaction conditions alters the content of carbonaceous species in the starting material.  These effects must be carefully decoupled in order to study the reactivity of SWNT. 

     Sonopolymer generation and removal was studied using thermal gravimetric analysis (TGA) and attenuated total reflectance - Fourier transform infrared spectroscopy (ATR).  The effect of sonopolymer removal on functional groups was monitored via resonant Raman spectroscopy (Raman), under low laser powers.  The extent of reaction and inherent doping effect on the nanotubes is unknown for CoMoCAT^® SWNT.  We examine these effects with treatment time using Raman.  In addition to ATR, coupled TGA-FTIR data was used to examine thermal stability of components and to provide confirmation of the surface functional groups present.  Finally, factors controlling the high-shear dispersibility of the Bingel SWNT in to UPR were studied.  Remarkably, SWNT sonicated in o-DCB alone show no re-dispersion in UPR while Bingel functionalized SWNT do disperse.