Non-covalent interactions between ionic liquid and graphene nanoplatelets as a tool to fine tune the properties of styrene butadiene rubber nanocomposites

Achieving a robust interfacial interaction between the filler and polymer matrix is crucial for the production of polymer nanocomposites with superior performance. 1-butyl-3-methyl imidazolium bromide (BMIB) was used to fine-tune the surface properties of graphene nanoplatelets (GnP) in the preparation of ionic liquid (IL)-functionalized styrene-butadiene rubber (SBR) nanocomposites. The combined results of Fourier transformation infrared (FTIR) spectroscopy, Raman spectroscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) confirmed multiple non-covalent interactions between BMIB molecules and GnP in modified graphene (IMG). FTIR and XRD studies confirmed the role of IL as an efficient surface modifier for the uniform dispersion of GnP in the SBR matrix via secondary interactions. And the TEM micrographs revealed an even dispersion of IMG in the SBR matrix. TGA and DTG studies showed significant improvements in the thermal stability of SBR nanocomposites with IMG loading. The Cole-Cole plot showed imperfect semicircles for all the filled systems, indicating heterogeneity. The novel SBR nanocomposites showed an improvement of 271% in tensile strength with 10-phr IMG loading