Synthesis of Phosphorus-Containing Flame Retardant Monomer and Grafting of PET Fabrics via Electron Beam Irradiation

The flame retardant, diethyl methacryloylphosphoramidate (DMPP), was synthesized by the reaction of diethyl chlorophosphate with methacrylamide and triethylamine. DMPP was grafted onto polyethylene terephthalate (PET) fabrics by electron beam (EB) irradiation. scanning electron microscopy (SEM) images and Fourier transform-infrared (FT-IR) spectra showed that the flame retardant was successfully grafted on the surface of PET fabrics. The morphology of the grafted fabrics after burning showed a porous protective layer on the surface. The FT-IR spectra showed that the flame retardant generated a large amount of phosphorus oxygen-nitrogen compounds after burning. The limiting oxygen index (LOI) of the grafted fabrics increased with the increase of DMPP concentration. The char length of fabrics treated with DMPP after combustion decreased from 30 cm to 5.9 cm, which demonstrated effective flame resistance.