Particulate nanocomposites based on bismaleimide–graphene oxide: Thermal studies

Abstract

The structurally different bismaleimides (BMIs) such as 4,4’-bismaleimidodiphenyl ether (BMIE), 4,4’-bismaleimidodiphenyl sulphone (BMIS) and 4,4’-bismaleimidodiphenyl methane (BMIM) were synthesized. The materials graphite (G), graphene oxide (GO) and washed graphene oxide (WGO) particles are separately blended (3% w/w) with BMIs and thermally polymerized under appropriate conditions. The effects of the presence of the nanoparticles in BMIs were investigated using Differential Scanning Calorimetry (DSC). The DSC results show that the blended nanoparticles alter both the cure exotherm and the enthalpy of curing of the BMIs. Thermogravimetric analysis (TGA) was employed to understand the thermal stability of the cured pure BMIs and their blends with nanoparticles. The presence of the nanoparticles in the crosslinked BMIE matrix shifts the onset of the thermal degradation temperature to higher temperature region (around 15 °C). Among all the materials investigated, the nanoparticles incorporated BMIS increases the char residue. This is due to the efficiency of the physical dispersion and the possible chemical interactions shown by nanoparticles in the cured bismaleimides. The SEM results reveal that the debris of GO are removed by the base washing of GO and the incorporated nanoparticles are well dispersed in the cured BMIM.