Synthesis and characterization of N-[4-(chlorocarbonyl)phenyl]maleimide functionalized graphene oxide and reduced graphene oxide

Functionalization of graphene oxide leads improvement in thermal stability and flame retardancy. Acid chloride terminated N-[4-(chlorocarbonyl)phenyl]maleimide (Cl-CPMI) was synthesized to decorate hydroxyl group in graphene oxide (GEO) and glycine-reduced GEO (RGEO). Structural characterization of the materials was performed using FTIR, C-13 NMR and Raman spectroscopic methods. Interlayer distance and surface morphology were also studied using X-ray diffraction and scanning electron microscopic methods, respectively. The absence of the band for C-Cl and shortening of the O-H band in the FTIR and peak in C-13 NMR spectra confirm the functionalization of alcoholic group on the graphitic plane with Cl-CPMI. The ratio, I-D/I-G computed from Raman study, the nature of XRD pattern and interlayer distance between the adjacent graphitic layers were not affected by the functionalization of GEO and RGEO using Cl-CPMI. The tagging of maleimide unit with the graphitic plane was also confirmed by the cloudy appearance in the SEM images.