Primaset(R) BADCy is a cyanate ester monomer which is soluble in Methyl Ethyl Ketone (MEK), acetone and other prepreg solvents.This monomer will dissolve in other cyanate esters (PT resins, METHYLCy, LECy), epoxy and BMI (Maleinbisimides) and thermoplastics
D. Preparation of bisphenol A dicyanate
456.60 g of 4,4'-isopropylidene diphenol (2.00 mol), 444.91 g of cyanogen bromide (4.20 mol) and 1,100 ml of acetone were added to the reactor and stirred under nitrogen protection. The stirred solution was cooled to -5°C and then 406.82 g of triethylamine (4.02 moles) was added slowly and dropwise over a period of 60 minutes, keeping the reaction temperature between -5 and -3°C. After the triethylamine was added, stirring was continued at -5 to -3°C for 25 minutes. Subsequently, the reaction mixture was poured into 5.685 liters of deionized water. After standing for 5 minutes, the aqueous phase and product mixture were extracted with dichloromethane (500 mL each time, three times). The combined dichloromethane extracts were sequentially washed with 500 ml of 0.05% by weight aqueous hydrochloric acid and 500 ml of deionized water and then dried over anhydrous sodium sulfate. The dried dichloromethane solution was filtered and the solvent was removed by rotary evaporation under reduced pressure at 100 °C for 60 min. 545.8 g of bisphenol A dicyanate was obtained in 98.1% yield and the product was a light tan crystalline solid. The structure of the product was confirmed by analyzing the product film sample by infrared spectroscopy (phenolic hydroxyl absorption peak disappeared and cyanate absorption peak appeared).
[1] Patent: EP291552, 1988, A1
[2] Patent: EP409069, 1991, A2
[3] Journal of Crystallographic and Spectroscopic Research, 1990, vol. 20, # 3, p. 285 - 289
[4] Russian Journal of Organic Chemistry, 2009, vol. 45, # 1, p. 154 - 157