Phosphorus oxychloride and melamine were used to synthesize novel halogen-free flame retardants,which contained phosphorus and nitrogen in its molecular structure.The optimal process conditions for synthesis were discussed,that was,the molar ratio of phosphorus oxychloride to melamine was 1/3,and the reaction yield was 95.7％at 100 ℃ for 8 h under one-step control of the synthetic product.Infrared spectrum(FTIR)and nuclear magnetic(1H-NMR)and characterization methods were applied to identify the synthesized target products'structure.The thermal stability of the products was characterized by thermal analysis(TG-DTA).The synthetic product was respectively added to epoxy resin and PBT to test the flame retardant performance.The results showed the LOI value of the epoxy resins increased with the additive amount of phosphoryl melamine,and reached 32％,fire retardant grade when the amount of synthesized target flame retardant was 16％.As the amount of synthetic product added to PBT was 20％,its LOI value reached 31％,achieving a better flame retardant effect.
维普
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