Rationally designed rare earth elements functionalized MoS2 nanosheets towards reducing fire hazards of epoxy resin

Abstract

It is well known that rare earth elements have the potential for enhancing the flame retardancy of polymer materials. Herein, a novel 0D/2D structure of cerium stannate (Ce₂Sn₂O₇) hybridized with molybdenum disulfide (CSO@MoS₂) was synthesized by an in situ co-precipitation method. The structure and morphology of the CSO@MoS₂ hybrid were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The effects of the CSO@MoS₂ hybrid on the fire safety properties of epoxy resin (EP) were investigated. The scanning electron microscopy (SEM) results showed the CSO@MoS₂ hybrid achieved a desired dispersion in EP composites and endowed outstanding thermal stability and flame retardancy to the EP. The EP/CSO@MoS₂ composites exhibited 27%, 31%, 28%, 35%, 40%, and 29% reductions in the peak heat release rate (PHRR), total heat release (THR), peak smoke release rate (PSPR), total smoke release (TSP), peak CO production rate (PCO), and peak CO₂ production rate (PCO₂), respectively, compared with those of neat EP. The improved fire safety performance of the EP composites was attributed to the catalytic carbon formation ability of the rare earth elements and the physical barrier effect of the MoS₂ nanosheets. This provides a simple and efficient strategy for the utilization of rare earth resources in ensuring the fire safety of EP composites.