The Main Preparation Method Of Polyethersulfone

A method for synthesizing polyethersulfone resin, the main raw materials of which are bisphenol S and 4,4-dichlorodiphenyl sulfone in non-equal molar ratios, wherein the bisphenol S and 4,4-dichlorodiphenyl sulfone The molar ratio is 0.90~0.999:1; the mass ratio of solvent used in the reaction process is 3:5~5:2 mixed solvent of dimethyl sulfone and sulfolane, xylene is used as dehydrating agent, K2CO3 is used as salt forming agent, the whole reaction The process was carried out under nitrogen protection. The solid content of the system is controlled at 25%~40%, the xylene is 10%~20% of the solvent weight, and the molar amount of K2CO3 is 1.01~1.1 times that of bisphenol S.

The specific steps are: add 0.5 mol of 4,4-dichlorodiphenyl sulfone, 0.4985 mol of bisphenol S, and 3:5 mass ratio of dimethyl sulfone to sulfolane into a four-necked flask equipped with a condensation water separator and a thermometer. Mix solvent 987.45g, xylene 148.118g and K2CO372.3321g, stir and heat up under nitrogen protection until all the added substances are dissolved and continue to heat up to 100°C~110°C, the reaction system starts to azeotrope, the upper layer of xylene is refluxed into the flask, The moisture in the lower layer flows out directly. During the reaction process, the above-mentioned mixed solvent was continuously added dropwise to replace the steamed water to maintain the liquid level balance. After all the water in the reaction system was azeotropically taken out, the reflux was continued for 30 minutes to steam out the xylene. Raise the temperature to 220°C, continue the reaction for 4-5 hours, then stop heating and continue flushing with nitrogen until the solution temperature is 95°C-100°C. The solution was slowly poured onto a clean glass plate and placed in a fume hood to cool naturally to room temperature. The obtained product was dried in a vacuum oven, crushed and then boiled repeatedly with distilled water for 10 times to remove the solvent and by-products in the product, and use The AgNO3 solution is detected until no white precipitate appears, and then dried in a vacuum oven to obtain polyethersulfone resin.