Because the polymeric material containing organic phosphorus compounds will form a graphite-like carbonization film on the surface of the material when burning, so that the polymer is isolated from the air, it has good flame retardant performance, high flame retardant efficiency, low volatility, good oil resistance and hydrolysis resistance, and is more and more widely used, and will gradually replace the inorganic and halogen-containing flame retardant materials used today. Using o-phenylphenol as raw material, a new phosphorus-containing flame retardant intermediate DOPO can be synthesized, which mainly has the following applications: (1) Synthetic flame retardant polyester DOP0 is used as raw material to react with itaconic acid to generate the intermediate ODOP-BDA, which can partially replace ethylene glycol to obtain a new phosphorus-containing flame retardant polyester. Studies have shown that polyester exhibits good flame retardant effect when the phosphorus content in PET and PEN reaches 0.75% and 0.5%, respectively. Based on 10,000 tons of polyester, if 5% of it is phosphorus-containing flame retardant polyester, more than 50t/a of o-phenylphenol is required. (2) Synthetic flame retardant epoxy resin epoxy resin has excellent adhesive properties, electrical insulation properties and other advantages, widely used in adhesives, electronic instruments, aerospace, coatings and advanced composite materials and other fields, in 2004 the world's epoxy resin consumption has reached more than 200,000 tons/year. DOPO reacts with benzoquinone to form ODOPB, which partially replaces bisphenol A to form a new epoxy resin with flame retardant properties. The results show that the flame retardant effect of the newly synthesized phosphorus-containing flame retardant epoxy resin is better than that of the Br flame retardant epoxy resin containing 17.26% when the P content is 2.1%, and it does not produce smoke, and the thermal stability is also better than that of the epoxy resin without flame retardant. (3) To improve the organic solubility of polymers, DOPO was used as raw material to synthesize 2DOPO-A to partially replace the monomer DABP of synthetic polyamide, and the new polyamide obtained was soluble in solvents such as NMP, DMAc, DMF, and DMSO, and at the same time, the thermal stability and flame retardancy at high temperature were also significantly improved. (4) As an intermediate in the synthesis of antioxidants, Taiwan patent reports the synthesis of phosphorus-containing antioxidants with DOPO, antioxidants for unsaturated polyesters, phenols and oils, and copper-based sheets used by Formosa Plastics Group for computers, and has good thermal stability. (5) Stabilizer for synthetic polymer materialsThe Japanese patent reports that the stabilizer of polymer materials synthesized by DOPO, adding this compound during the processing of polyethylene, polypropylene, and polyvinyl chloride can improve the stability of polymer compounds during thermal processing. (6) Synthetic light-emitting parent organic light-emitting diode is an important optoelectronic material, Sun et al. used DOPO derivatives as monomers to synthesize polymers with luminescent properties, DOPO derivatives play the role of emission clusters, can emit blue light with a wavelength of 325-350nm, and can be applied to organic light-emitting diodes.
