Viscoelastic changes in chlorinated butyl rubber modified with graphene oxide

Abstract

The glass–rubber transition region in multiple component systems is significant for studying the slow relaxation processes in amorphous polymers. It is the first time that graphene oxide (GO) is added into chlorinated butyl rubber (CIIR) to study the effect of GO on different relaxation processes of CIIR. We aimed to give a possible insight to the molecular relaxation behaviors of CIIR/GO nanocomposites. In this study, GO was synthesized by a revised Hummers method, and it was incorporated with CIIR at different contents of 0, 1, 2, 3 and 5 phr (parts per hundred rubber). The structure of GO and CIIR/GO nanocomposites was studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), scanning electron microscopy (SEM) and transmission electron microscope (TEM).Bound rubber was adopted to study the interfacial interaction between GO and CIIR. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were also performed. Since there were many conflicting results on the effect of nanoparticles in relation to the glass transition temperature (T g) of polymer matrixes in correlative literature, we investigated the effect of GO on that of CIIR. The T g determined by DSC shows slight shifting. However, the maximum and the shoulder of tan δ both shift to low temperatures. In addition, GO increases the coupling effect of CIIR, resulting the shoulder merged with the maximum. A mechanism, though still needs to be further refined, has been proposed to interpret the contradictory results in our case.