Epoxy functionalized multi-walled carbon nanotubes for improved adhesives

TitleEpoxy functionalized multi-walled carbon nanotubes for improved adhesives
Publication TypeJournal Article
Year of Publication2013
AuthorsSydlik, SA, Lee, J-H, Walish, JJ, Thomas, EL, Swager, TM
PaginationAhead of Print
Date Publishedmar

Three different types of epoxy-functionalized multi-walled carbon nanotubes (EpCNTs) were prepd. by multiple covalent functionalization methods. The EpCNTs were characterized by thermogravimetric anal. (TGA), IR spectroscopy (FTIR), and Raman spectroscopy to confirm covalent functionalization. The effect of the different chemistries on the adhesive properties was compared to a neat com. epoxy (Hexion formulation 4007) using functionalized and unfunctionalized multi-walled carbon nanotubes (MWCNT) at 0.5, 1, 2, 3, 5, and 10 wt%. It was found that an EpCNT at 1 wt% increased the lap shear strength, tested using the American Society for Testing and Materials std. test D1002, by 36% over the unfilled epoxy formulation and by 27% over a 1 wt% unmodified MWCNT control sample. SEM images revealed a fracture surface morphol. change with the incorporation of EpCNT and a deflection of the crack fronts at the site of embedded CNTs, as the mechanism accounting for increased adhesive strength. Rheol. studies showed non-linear viscosity and DSC cure studies showed an alteration of cure kinetics with increased CNT concn., and these effects were more pronounced for EpCNT. [on SciFinder(R)]