Background and overview[1]
9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is also called 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide ( DOPO) is an important new reactive phosphorus-containing flame retardant. The flame retardant synthesized by DOPO and its derivatives has the characteristics of high efficiency, halogen-free, smoke-free, non-toxic, non-migration, and long-lasting flame retardant performance. DOPO can be used for flame retardant of a variety of polymer materials, such as linear polyester, epoxy resin, bismaleimide, etc., and is widely used for flame retardant of electronics, synthetic fibers, semiconductor packaging materials, etc. At the same time, DOPO and its derivatives can also be used for chemical modification of polymer materials due to their special functions. In addition, DOPO can also be used as a pesticide, fungicide, curing agent, antioxidant, stabilizer, photoinitiator, binder, blocking agent for harmful metal ions, lightening agent for organic matter, and ultraviolet light absorber.
Preparation[1-2]
Report 1,
OPP (200g, 1.175mol) and anhydrous zinc chloride (1.6g, 0.0115mol) were added to the four-necked bottle. At 70°C, phosphorus trichloride (113mL, 1.292mol) was added dropwise within 3 hours; After completion, the temperature was raised to 180°C, and the reaction was kept for 10 hours. During this period, phosphorus trichloride (20.5 mL, 0.234 mol) was evenly added until no HCl gas was released, and a reaction solution containing the intermediate CDOP was obtained. Cool the reaction solution to 90±2°C, release the material into a solution consisting of sodium hydroxide (140.4g, 3.51mol) and water (560mL), cool to 40±2°C, stir for 1 hour, and filter. Adjust the pH of the filtrate to 1.0 with the hydrochloric acid produced in the first step of the reaction, stir for 3 hours at 40±2°C, crystallize the solid saturated polyester, filter it with suction, and wash it three times with distilled water (200 mL × 3); dissolve the solid in toluene (mL) , reflux for 1 hour, cool to room temperature, crystallize, and filter to obtain the hydrolyzate HPPA. The obtained HPPA was heated to 150°C and distilled under reduced pressure for 0.5 h under vacuum degree ≥ 30 mmHg to obtain the target product DOPO (231 g, 92%). Purity is 99.2% (HPLC). Melting point: 117~119℃; zinc ion content: 2ppm.
Report 2,
Weigh 170g of OPP, and take 1.25 times the mole number of OPP as phosphorus trichloride for later use. Add OPP and 0.8% of OPP mass of anhydrous zinc chloride into a 500mL four-neck bottle, and raise the temperature to 79 in 2-4 hours. -81°C, add 30% phosphorus trichloride dropwise within 2-4 hours, continue to raise the temperature to 179-182°C, add 50% phosphorus trichloride dropwise within the next 4-6 hours, and keep warm 6-10 hours, the remaining phosphorus trichloride is added dropwise within the first 3 hours of the heat preservation stage, the temperature is cooled to 8 conductive carbon black 5-90°C, excess phosphorus trichloride is evaporated under reduced pressure, and OPP quality Mix 2% activated carbon and 70% isooctyl alcohol of OPP quality, stir, and filter under reduced pressure. Add the CDOP isooctyl alcohol solution dropwise to 350 mL of distilled water, raise the temperature to 90-95°C, hydrolyze for 1.5 hours, and cool down in an ice bath. The reaction solution was kept below 5°C for 1 hour, filtered under reduced pressure to obtain HPPA and washed three times with distilled water. The amount of distilled water added each time was 3.0 times the mass of OPP. After washing was completed, filtered under reduced pressure to obtain HPPA wet product. Toluene with a mass of 0.8 times the mass of OPP was added to the HPPA wet product, distilled under reduced pressure, raised to 110-120°C, dehydrated under reduced pressure for 1-1.5 hours, and discharged to obtain white lump DOPO, with a liquid chromatography purity of 99.5% , melting point: 117-119°C, chlorine content less than 37ppm, zinc content 8ppm, whiteness 95%.
