Graphene oxide (GO) was functionalized with pimelic acid (PA) on its surface to produce a -crystal nucleating agent. The functionalization was characterized by Fourier transform infrared spectroscopy, showing the presence of new bands at 1570 and 1406cm(-1) indicating a bridging bidentate link of the PA on the GO surface through the Ca used during the functionalization. These observations were concomitant with the Raman spectroscopy results where the D-G intensity ratio increased, suggesting that the disorder in GO structure increased when the PA molecules are attached on the GO surface. The modified graphene oxide (GO-PA) showed high thermal stability, making it attractive for melt blending composites. These results were observed by thermal differential scanning calorimetry (DSC) and thermogravimetric analysis. The DSC and wide-angle X-ray diffraction (WAXD) results demonstrated that the modified GO is an excellent -nucleating promoter even at low percentages (0.05 GO-PA % w/w) in contrast to the unmodified GO. The content of -crystals under isothermal crystallization conditions reached a value as high as 92% by DSC while the extrudes prepared by compression and analyzed by WAXD showed a k=0.78 by Turner-Jones method at the same percentage of modified filler. The storage modulus for the iPP composites (GO/iPP and GO-PA/iPP) was in all cases higher than that for the raw iPP sample because of the presence of GO in the polymer matrix. However, a decrease in the storage modulus can be observed for the GO-PA/iPP composites because of the presence of high percentages of -crystal.