Study On Halogen-free Flameretardancy For Epoxy Resins

In this paper, a epoxy resin containing phosphorus, bisdiglycol spirocyclic pentaerythritol bisphosphorate(BDSPBP) and 2-carbonxylethyl(phenyl) phosphinic sulfanilammonium were synthesized and their chemical structures were characterized by FT-IR, Nuclear Magnetic Resonance Spectroscopy(NMR).Flammabilities and thermal behaviors of added BDSPBP of the cured resins, added CEPPSAA of the cured resins and added BDSPBP-others flame retardants of the cured resins were investigated by Limit Oxygen Index (LOI), Vertical Burning Test, Thermogravimetric Analysis (TGA).The flame-retardant mechanism of BDSPBP for epoxy resins was investigated by X-ray Photoelctron Spectroscopy (XPS), and Scanning electron microscope (SEM).Results show that added BDSPBP of the cured resins, added CEPPSAA of the cured resins and added BDSPBP-melamine of the cured resins could improve of epoxy resins to a great extent respectively. When the add-on of BDSPBP reaches 18%, the LOI of the added BDSPBP of the cured resins increases to 29.4 and UL-94 reaches V-0 grade. When the add-on of CEPPSAA reaches 20%, the LOI of the added CEPPSAA of the cured resins increases to 28.2 and UL-94 reaches V-0 grade. When the add-on of 15%BDSPBP-3%melamine reaches 18%, the LOI of the added BDSPBP-melamine of the cured resins increases to 31.5 and UL-94 reaches V-0 grade. The TGA thermograms indicate BDSPBP is an effective charring agent because the epoxy resin containing BDSPBP has high char yields, at high temperatures. The char, the decomposition product of BDSPBP, has outstanding...