Preparation of a novel flame retardant based on diatomite/polyethyleneimine modified MWCNT for applications in silicone rubber composites

Abstract

A new flame retardant, DM/PEI/MWCNT, was prepared by self-assembly method based on non-covalent interactions between hydroxyl and amino groups on the surface of hydroxyl multi-walled carbon nanotubes (MWCNT), polyethyleneimine (PEI) and diatomite (DM). The flame-retardant composites were prepared by adding DM/PEI/MWCNT to room-temperature vulcanisated silicone rubber (RTV-silicone). The structure of the flame retardant and composites was characterised by polarising light microscope, scanning electron microscopy and Fourier-transform infrared spectroscopy. The flame retardancy of composites was studied by limited oxygen index and cone calorimeter measurement. Results showed that RTV-silicone composites with DM/PEI/MWCNT owned better flame retardancy. In addition, DM/PEI/MWCNT exhibited better compatibility in silicone rubber than that of unmodified DM, and the tensile properties of RTV-silicone/DM/PEI/MWCNT composites were improved compared to pure RTV-silicone.