Study on the synthesis of boric ester brake fluid

Two kinds of propylene oxide polyether based on butanol and methanol and their boric esters are synthesized. Diethanolamine boric ester is also synthesized and the optimal reaction conditions are reviewed. The optimal synthesis process for such amino alcohol boric ester is as follows: n (diethanol amine)∶ n (boric acid) = 3∶1, the reaction temperature is 130℃ and the reaction time is 3 hours. Primary characteristics of the synthesized product are analyzed by IR. Two kinds of boric ester brake fluid are prepared, and the performance test results show that properties of the brake fluid reach the American DOT 4 standard.