To take advantage of the benefits of chemical functionalization and the desirable properties of unfunctionalized SWNTs, this research studies the effect of removing functional groups from SWNTs dispersed in a polymer matrix. Chemical functionalization of single wall carbon nanotubes (SWNTs) is a method for disrupting rope structure and adding reactive species to the nanotube to improve interfacial bonding and load transfer in composites, but changes to the nanotube hexagon structure caused by chemical modifications are expected to have a detrimental effect on the SWNTs' intrinsic mechanical properties. Thus, composites containing defunctionalized SWNTs and polyethylene are analyzed to evaluate the effect of functional group removal on the mechanical properties. The mechanical properties are measured using tensile tests. Issues of defects in the SWNT structure, polymer degradation, and changes in the fiber/matrix bonding as a result of functionalization removal are studied using Raman spectroscopy, thermogravimetric analysis, infrared spectroscopy, and dynamic mechanical analysis.