Mechanical, thermal, and rheological studies of phenolic resin modified with intercalated graphite prepared via liquid phase intercalation

In this study, phenolic resole resin was modified at polymeric level with a particulate additive (intercalated graphite (IG)), and its effect on mechanical, thermal and rheological properties was studied. Intercalated graphite was prepared via liquid phase intercalation method using H2SO4 as the intercalant species and KMnO4 as the oxidizer. X-Ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM) image and Fourier Transform Infra-Red (FTIR) spectrum confirmed the formation of intercalated species. Composites with three different IG concentrations were prepared using tetrahydrofuran (THF) as the solvent. Thermogravimetric analysis (TGA) of the composites showed improvement in degradation temperature and char yield even at 1% IG concentration. The mechanical and ageing properties were evaluated using Universal Testing Machine (UTM) as per ASTM standards. Visible enhancement in properties (about 25% rise in tensile strength) for the composites was observed in the studies. The addition of intercalated graphite also enhanced the shelf life. Moreover, phenolic resin - IG composites showed superior properties than composites with natural graphite as a modifier due to better dispersion. Rheological characterizations were also done to study the flow behavior of resin systems.