Carbon Nanotubes to Improve Short Glass Fiber Composites

This paper discusses the potential use of multi-walled carbon nanotubes (MWCNTs) to improve the mechanical properties of short glass fiber composites. Two methods to incorporate MWCNTs in short glass fiber composite fabrication were examined. First, Carboxylic-functionalized MWCNTs were dispersed in a silane fiber sizing material and then were allowed to bond to the surface of glass fibers. Second, MWCNTs were grown on the surface of glass fibers using the chemical vapor deposition (CVD) method. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to examine the significance of MWCNTs on fiber surface. Fourier Transform Infrared (FTIR) analysis was also used to identify chemical reactions between MWCNTs, the glass fiber surface, and the sizing material. Short MWCNTsmodified glass fiber reinforced epoxy composites were also fabricated. Mechanical properties of the MWCNTs-modified composites were compared with short glass fiber composites produced with neat fibers using dynamic mechanical analysis (DMA). The experimental investigation showed that dispersing MWCNTs in a silane sizing agent is more efficient than growing MWCNTs on the surface of glass fibers. A significant improvement in the storage elastic modulus was observed when MWCNTs were dispersed in silane. FTIR analysis confirmed the formation of chemical bonds between both COOH–MWCNTs and the glass fiber surface. No significant difference in the loss modulus (i.e. time dependent behavior) of the glass fiber composites was found with the different methods of incorporating MWCNTs during composite fabrication.