Interphase tailoring via π-cation interaction in graphene and graphene oxide containing NR nanocomposites prepared by latex compounding

Abstract Natural rubber (NR) latex was modified with graphene (GR) and graphene oxide (GO). These flaky carbonaceous nanofillers were characterized by Raman and X-ray photoelectron spectroscopy techniques, and added to NR in an amount of up to 5 parts per hundred rubber (phr) in the presence and absence of cetyltrimethyl ammonium bromide (CTAB). CTAB was supposed to trigger π-cation interactions with GR and GO. Interfacial changes were examined by Raman and infrared spectroscopy techniques, dynamic mechanical analysis and differential scanning calorimetry. The dispersion of the nanofillers using scanning electron microscopy was studied. It was found that CTAB prominently affected the reinforcing efficiency and mechanical loss of the NR nanocomposites, which was traced to changes in the NR fraction immobilized on the filler's surfaces. The π-cation interaction between GR, GO and CTAB, for which indirect proof was found, seems to be a useful tool to tailor the interphase, and thus the related properties (mechanical loss, reinforcing and Payne effects) in the corresponding NR nanocomposites.